From 9ebc57cfaad21aacbc363eecead579269a46b493 Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Tue, 12 Apr 2016 20:39:55 -0400 Subject: [PATCH 01/45] tracing: Rename check_ignore_pid() to ignore_this_task() The name "check_ignore_pid" is confusing in trying to figure out if the pid should be ignored or not. Rename it to "ignore_this_task" which is pretty straight forward, as a task (not a pid) is passed in, and should if true should be ignored. Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 14 +++++++------- 1 file changed, 7 insertions(+), 7 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 05ddc0820771..598a18675a6b 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -484,7 +484,7 @@ static int cmp_pid(const void *key, const void *elt) } static bool -check_ignore_pid(struct trace_pid_list *filtered_pids, struct task_struct *task) +ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task) { pid_t search_pid; pid_t *pid; @@ -517,8 +517,8 @@ event_filter_pid_sched_switch_probe_pre(void *data, bool preempt, pid_list = rcu_dereference_sched(tr->filtered_pids); this_cpu_write(tr->trace_buffer.data->ignore_pid, - check_ignore_pid(pid_list, prev) && - check_ignore_pid(pid_list, next)); + ignore_this_task(pid_list, prev) && + ignore_this_task(pid_list, next)); } static void @@ -531,7 +531,7 @@ event_filter_pid_sched_switch_probe_post(void *data, bool preempt, pid_list = rcu_dereference_sched(tr->filtered_pids); this_cpu_write(tr->trace_buffer.data->ignore_pid, - check_ignore_pid(pid_list, next)); + ignore_this_task(pid_list, next)); } static void @@ -547,7 +547,7 @@ event_filter_pid_sched_wakeup_probe_pre(void *data, struct task_struct *task) pid_list = rcu_dereference_sched(tr->filtered_pids); this_cpu_write(tr->trace_buffer.data->ignore_pid, - check_ignore_pid(pid_list, task)); + ignore_this_task(pid_list, task)); } static void @@ -564,7 +564,7 @@ event_filter_pid_sched_wakeup_probe_post(void *data, struct task_struct *task) /* Set tracing if current is enabled */ this_cpu_write(tr->trace_buffer.data->ignore_pid, - check_ignore_pid(pid_list, current)); + ignore_this_task(pid_list, current)); } static void __ftrace_clear_event_pids(struct trace_array *tr) @@ -1561,7 +1561,7 @@ static void ignore_task_cpu(void *data) mutex_is_locked(&event_mutex)); this_cpu_write(tr->trace_buffer.data->ignore_pid, - check_ignore_pid(pid_list, current)); + ignore_this_task(pid_list, current)); } static ssize_t From f4d34a87e9c10f0ffd03d3548db6bfb200d06cdf Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 13 Apr 2016 16:27:49 -0400 Subject: [PATCH 02/45] tracing: Use pid bitmap instead of a pid array for set_event_pid In order to add the ability to let tasks that are filtered by the events have their children also be traced on fork (and then not traced on exit), convert the array into a pid bitmask. Most of the time the number of pids is only 32768 pids or a 4k bitmask, which is the same size as the default list currently is, and that list could grow if more pids are listed. This also greatly simplifies the code. Suggested-by: "H. Peter Anvin" Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 5 +- kernel/trace/trace_events.c | 221 ++++++++++++++++-------------------- 2 files changed, 102 insertions(+), 124 deletions(-) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 3fff4adfd431..68cbb8e10aea 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -177,9 +177,8 @@ struct trace_options { }; struct trace_pid_list { - unsigned int nr_pids; - int order; - pid_t *pids; + int pid_max; + unsigned long *pids; }; /* diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 598a18675a6b..45f7cc72bf25 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -15,7 +15,7 @@ #include #include #include -#include +#include #include #include #include @@ -471,23 +471,13 @@ static void ftrace_clear_events(struct trace_array *tr) mutex_unlock(&event_mutex); } -static int cmp_pid(const void *key, const void *elt) -{ - const pid_t *search_pid = key; - const pid_t *pid = elt; - - if (*search_pid == *pid) - return 0; - if (*search_pid < *pid) - return -1; - return 1; -} +/* Shouldn't this be in a header? */ +extern int pid_max; static bool ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task) { - pid_t search_pid; - pid_t *pid; + pid_t pid; /* * Return false, because if filtered_pids does not exist, @@ -496,15 +486,16 @@ ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task) if (!filtered_pids) return false; - search_pid = task->pid; + pid = task->pid; - pid = bsearch(&search_pid, filtered_pids->pids, - filtered_pids->nr_pids, sizeof(pid_t), - cmp_pid); - if (!pid) + /* + * If pid_max changed after filtered_pids was created, we + * by default ignore all pids greater than the previous pid_max. + */ + if (task->pid >= filtered_pids->pid_max) return true; - return false; + return !test_bit(task->pid, filtered_pids->pids); } static void @@ -602,7 +593,7 @@ static void __ftrace_clear_event_pids(struct trace_array *tr) /* Wait till all users are no longer using pid filtering */ synchronize_sched(); - free_pages((unsigned long)pid_list->pids, pid_list->order); + vfree(pid_list->pids); kfree(pid_list); } @@ -946,11 +937,32 @@ static void t_stop(struct seq_file *m, void *p) mutex_unlock(&event_mutex); } +static void * +p_next(struct seq_file *m, void *v, loff_t *pos) +{ + struct trace_array *tr = m->private; + struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids); + unsigned long pid = (unsigned long)v; + + (*pos)++; + + /* pid already is +1 of the actual prevous bit */ + pid = find_next_bit(pid_list->pids, pid_list->pid_max, pid); + + /* Return pid + 1 to allow zero to be represented */ + if (pid < pid_list->pid_max) + return (void *)(pid + 1); + + return NULL; +} + static void *p_start(struct seq_file *m, loff_t *pos) __acquires(RCU) { struct trace_pid_list *pid_list; struct trace_array *tr = m->private; + unsigned long pid; + loff_t l = 0; /* * Grab the mutex, to keep calls to p_next() having the same @@ -963,10 +975,18 @@ static void *p_start(struct seq_file *m, loff_t *pos) pid_list = rcu_dereference_sched(tr->filtered_pids); - if (!pid_list || *pos >= pid_list->nr_pids) + if (!pid_list) return NULL; - return (void *)&pid_list->pids[*pos]; + pid = find_first_bit(pid_list->pids, pid_list->pid_max); + if (pid >= pid_list->pid_max) + return NULL; + + /* Return pid + 1 so that zero can be the exit value */ + for (pid++; pid && l < *pos; + pid = (unsigned long)p_next(m, (void *)pid, &l)) + ; + return (void *)pid; } static void p_stop(struct seq_file *m, void *p) @@ -976,25 +996,11 @@ static void p_stop(struct seq_file *m, void *p) mutex_unlock(&event_mutex); } -static void * -p_next(struct seq_file *m, void *v, loff_t *pos) -{ - struct trace_array *tr = m->private; - struct trace_pid_list *pid_list = rcu_dereference_sched(tr->filtered_pids); - - (*pos)++; - - if (*pos >= pid_list->nr_pids) - return NULL; - - return (void *)&pid_list->pids[*pos]; -} - static int p_show(struct seq_file *m, void *v) { - pid_t *pid = v; + unsigned long pid = (unsigned long)v - 1; - seq_printf(m, "%d\n", *pid); + seq_printf(m, "%lu\n", pid); return 0; } @@ -1543,11 +1549,6 @@ show_header(struct file *filp, char __user *ubuf, size_t cnt, loff_t *ppos) return r; } -static int max_pids(struct trace_pid_list *pid_list) -{ - return (PAGE_SIZE << pid_list->order) / sizeof(pid_t); -} - static void ignore_task_cpu(void *data) { struct trace_array *tr = data; @@ -1571,7 +1572,7 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, struct seq_file *m = filp->private_data; struct trace_array *tr = m->private; struct trace_pid_list *filtered_pids = NULL; - struct trace_pid_list *pid_list = NULL; + struct trace_pid_list *pid_list; struct trace_event_file *file; struct trace_parser parser; unsigned long val; @@ -1579,7 +1580,7 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, ssize_t read = 0; ssize_t ret = 0; pid_t pid; - int i; + int nr_pids = 0; if (!cnt) return 0; @@ -1592,10 +1593,43 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, return -ENOMEM; mutex_lock(&event_mutex); + filtered_pids = rcu_dereference_protected(tr->filtered_pids, + lockdep_is_held(&event_mutex)); + /* - * Load as many pids into the array before doing a - * swap from the tr->filtered_pids to the new list. + * Always recreate a new array. The write is an all or nothing + * operation. Always create a new array when adding new pids by + * the user. If the operation fails, then the current list is + * not modified. */ + pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL); + if (!pid_list) { + read = -ENOMEM; + goto out; + } + pid_list->pid_max = READ_ONCE(pid_max); + /* Only truncating will shrink pid_max */ + if (filtered_pids && filtered_pids->pid_max > pid_list->pid_max) + pid_list->pid_max = filtered_pids->pid_max; + pid_list->pids = vzalloc((pid_list->pid_max + 7) >> 3); + if (!pid_list->pids) { + kfree(pid_list); + read = -ENOMEM; + goto out; + } + if (filtered_pids) { + /* copy the current bits to the new max */ + pid = find_first_bit(filtered_pids->pids, + filtered_pids->pid_max); + while (pid < filtered_pids->pid_max) { + set_bit(pid, pid_list->pids); + pid = find_next_bit(filtered_pids->pids, + filtered_pids->pid_max, + pid + 1); + nr_pids++; + } + } + while (cnt > 0) { this_pos = 0; @@ -1613,92 +1647,35 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, ret = -EINVAL; if (kstrtoul(parser.buffer, 0, &val)) break; - if (val > INT_MAX) + if (val >= pid_list->pid_max) break; pid = (pid_t)val; - ret = -ENOMEM; - if (!pid_list) { - pid_list = kmalloc(sizeof(*pid_list), GFP_KERNEL); - if (!pid_list) - break; + set_bit(pid, pid_list->pids); + nr_pids++; - filtered_pids = rcu_dereference_protected(tr->filtered_pids, - lockdep_is_held(&event_mutex)); - if (filtered_pids) - pid_list->order = filtered_pids->order; - else - pid_list->order = 0; - - pid_list->pids = (void *)__get_free_pages(GFP_KERNEL, - pid_list->order); - if (!pid_list->pids) - break; - - if (filtered_pids) { - pid_list->nr_pids = filtered_pids->nr_pids; - memcpy(pid_list->pids, filtered_pids->pids, - pid_list->nr_pids * sizeof(pid_t)); - } else - pid_list->nr_pids = 0; - } - - if (pid_list->nr_pids >= max_pids(pid_list)) { - pid_t *pid_page; - - pid_page = (void *)__get_free_pages(GFP_KERNEL, - pid_list->order + 1); - if (!pid_page) - break; - memcpy(pid_page, pid_list->pids, - pid_list->nr_pids * sizeof(pid_t)); - free_pages((unsigned long)pid_list->pids, pid_list->order); - - pid_list->order++; - pid_list->pids = pid_page; - } - - pid_list->pids[pid_list->nr_pids++] = pid; trace_parser_clear(&parser); ret = 0; } trace_parser_put(&parser); if (ret < 0) { - if (pid_list) - free_pages((unsigned long)pid_list->pids, pid_list->order); + vfree(pid_list->pids); kfree(pid_list); - mutex_unlock(&event_mutex); - return ret; + read = ret; + goto out; } - if (!pid_list) { - mutex_unlock(&event_mutex); - return ret; + if (!nr_pids) { + /* Cleared the list of pids */ + vfree(pid_list->pids); + kfree(pid_list); + read = ret; + if (!filtered_pids) + goto out; + pid_list = NULL; } - - sort(pid_list->pids, pid_list->nr_pids, sizeof(pid_t), cmp_pid, NULL); - - /* Remove duplicates */ - for (i = 1; i < pid_list->nr_pids; i++) { - int start = i; - - while (i < pid_list->nr_pids && - pid_list->pids[i - 1] == pid_list->pids[i]) - i++; - - if (start != i) { - if (i < pid_list->nr_pids) { - memmove(&pid_list->pids[start], &pid_list->pids[i], - (pid_list->nr_pids - i) * sizeof(pid_t)); - pid_list->nr_pids -= i - start; - i = start; - } else - pid_list->nr_pids = start; - } - } - rcu_assign_pointer(tr->filtered_pids, pid_list); list_for_each_entry(file, &tr->events, list) { @@ -1708,7 +1685,7 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, if (filtered_pids) { synchronize_sched(); - free_pages((unsigned long)filtered_pids->pids, filtered_pids->order); + vfree(filtered_pids->pids); kfree(filtered_pids); } else { /* @@ -1745,10 +1722,12 @@ ftrace_event_pid_write(struct file *filp, const char __user *ubuf, */ on_each_cpu(ignore_task_cpu, tr, 1); + out: mutex_unlock(&event_mutex); ret = read; - *ppos += read; + if (read > 0) + *ppos += read; return ret; } From c37775d57830a36382a9774bb84eca4ce3d019cc Mon Sep 17 00:00:00 2001 From: Steven Rostedt Date: Wed, 13 Apr 2016 16:59:18 -0400 Subject: [PATCH 03/45] tracing: Add infrastructure to allow set_event_pid to follow children Add the infrastructure needed to have the PIDs in set_event_pid to automatically add PIDs of the children of the tasks that have their PIDs in set_event_pid. This will also remove PIDs from set_event_pid when a task exits This is implemented by adding hooks into the fork and exit tracepoints. On fork, the PIDs are added to the list, and on exit, they are removed. Add a new option called event_fork that when set, PIDs in set_event_pid will automatically get their children PIDs added when they fork, as well as any task that exits will have its PID removed from set_event_pid. This works for instances as well. Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 3 ++ kernel/trace/trace.h | 2 + kernel/trace/trace_events.c | 84 ++++++++++++++++++++++++++++++++----- 3 files changed, 79 insertions(+), 10 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index a2f0b9f33e9b..0d12dbde8399 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3571,6 +3571,9 @@ int set_tracer_flag(struct trace_array *tr, unsigned int mask, int enabled) if (mask == TRACE_ITER_RECORD_CMD) trace_event_enable_cmd_record(enabled); + if (mask == TRACE_ITER_EVENT_FORK) + trace_event_follow_fork(tr, enabled); + if (mask == TRACE_ITER_OVERWRITE) { ring_buffer_change_overwrite(tr->trace_buffer.buffer, enabled); #ifdef CONFIG_TRACER_MAX_TRACE diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 68cbb8e10aea..2525042760e6 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -655,6 +655,7 @@ static inline void __trace_stack(struct trace_array *tr, unsigned long flags, extern cycle_t ftrace_now(int cpu); extern void trace_find_cmdline(int pid, char comm[]); +extern void trace_event_follow_fork(struct trace_array *tr, bool enable); #ifdef CONFIG_DYNAMIC_FTRACE extern unsigned long ftrace_update_tot_cnt; @@ -966,6 +967,7 @@ extern int trace_get_user(struct trace_parser *parser, const char __user *ubuf, C(STOP_ON_FREE, "disable_on_free"), \ C(IRQ_INFO, "irq-info"), \ C(MARKERS, "markers"), \ + C(EVENT_FORK, "event-fork"), \ FUNCTION_FLAGS \ FGRAPH_FLAGS \ STACK_FLAGS \ diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index 45f7cc72bf25..add81dff7520 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -474,11 +474,23 @@ static void ftrace_clear_events(struct trace_array *tr) /* Shouldn't this be in a header? */ extern int pid_max; +/* Returns true if found in filter */ +static bool +find_filtered_pid(struct trace_pid_list *filtered_pids, pid_t search_pid) +{ + /* + * If pid_max changed after filtered_pids was created, we + * by default ignore all pids greater than the previous pid_max. + */ + if (search_pid >= filtered_pids->pid_max) + return false; + + return test_bit(search_pid, filtered_pids->pids); +} + static bool ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task) { - pid_t pid; - /* * Return false, because if filtered_pids does not exist, * all pids are good to trace. @@ -486,16 +498,68 @@ ignore_this_task(struct trace_pid_list *filtered_pids, struct task_struct *task) if (!filtered_pids) return false; - pid = task->pid; + return !find_filtered_pid(filtered_pids, task->pid); +} - /* - * If pid_max changed after filtered_pids was created, we - * by default ignore all pids greater than the previous pid_max. - */ - if (task->pid >= filtered_pids->pid_max) - return true; +static void filter_add_remove_task(struct trace_pid_list *pid_list, + struct task_struct *self, + struct task_struct *task) +{ + if (!pid_list) + return; - return !test_bit(task->pid, filtered_pids->pids); + /* For forks, we only add if the forking task is listed */ + if (self) { + if (!find_filtered_pid(pid_list, self->pid)) + return; + } + + /* Sorry, but we don't support pid_max changing after setting */ + if (task->pid >= pid_list->pid_max) + return; + + /* "self" is set for forks, and NULL for exits */ + if (self) + set_bit(task->pid, pid_list->pids); + else + clear_bit(task->pid, pid_list->pids); +} + +static void +event_filter_pid_sched_process_exit(void *data, struct task_struct *task) +{ + struct trace_pid_list *pid_list; + struct trace_array *tr = data; + + pid_list = rcu_dereference_sched(tr->filtered_pids); + filter_add_remove_task(pid_list, NULL, task); +} + +static void +event_filter_pid_sched_process_fork(void *data, + struct task_struct *self, + struct task_struct *task) +{ + struct trace_pid_list *pid_list; + struct trace_array *tr = data; + + pid_list = rcu_dereference_sched(tr->filtered_pids); + filter_add_remove_task(pid_list, self, task); +} + +void trace_event_follow_fork(struct trace_array *tr, bool enable) +{ + if (enable) { + register_trace_prio_sched_process_fork(event_filter_pid_sched_process_fork, + tr, INT_MIN); + register_trace_prio_sched_process_exit(event_filter_pid_sched_process_exit, + tr, INT_MAX); + } else { + unregister_trace_sched_process_fork(event_filter_pid_sched_process_fork, + tr); + unregister_trace_sched_process_exit(event_filter_pid_sched_process_exit, + tr); + } } static void From 540b589e6349779c0eeb8de82450b62a4569ffd9 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 19 Apr 2016 10:24:38 -0400 Subject: [PATCH 04/45] tracing: Update the documentation to describe "event-fork" option Add documentation to the ftrace.txt file in Documentation to describe the event-fork option. Also add the missing "display-graph" option now that it shows up in the trace_options file (from a previous commit). Signed-off-by: Steven Rostedt --- Documentation/trace/ftrace.txt | 34 ++++++++++++++++++++++++---------- 1 file changed, 24 insertions(+), 10 deletions(-) diff --git a/Documentation/trace/ftrace.txt b/Documentation/trace/ftrace.txt index f52f297cb406..fdf18485db2b 100644 --- a/Documentation/trace/ftrace.txt +++ b/Documentation/trace/ftrace.txt @@ -210,6 +210,11 @@ of ftrace. Here is a list of some of the key files: Note, sched_switch and sched_wake_up will also trace events listed in this file. + To have the PIDs of children of tasks with their PID in this file + added on fork, enable the "event-fork" option. That option will also + cause the PIDs of tasks to be removed from this file when the task + exits. + set_graph_function: Set a "trigger" function where tracing should start @@ -725,16 +730,14 @@ noraw nohex nobin noblock -nostacktrace trace_printk -noftrace_preempt nobranch annotate nouserstacktrace nosym-userobj noprintk-msg-only context-info -latency-format +nolatency-format sleep-time graph-time record-cmd @@ -742,7 +745,10 @@ overwrite nodisable_on_free irq-info markers +noevent-fork function-trace +nodisplay-graph +nostacktrace To disable one of the options, echo in the option prepended with "no". @@ -796,11 +802,6 @@ Here are the available options: block - When set, reading trace_pipe will not block when polled. - stacktrace - This is one of the options that changes the trace - itself. When a trace is recorded, so is the stack - of functions. This allows for back traces of - trace sites. - trace_printk - Can disable trace_printk() from writing into the buffer. branch - Enable branch tracing with the tracer. @@ -897,6 +898,10 @@ x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6] When disabled, the trace_marker will error with EINVAL on write. + event-fork - When set, tasks with PIDs listed in set_event_pid will have + the PIDs of their children added to set_event_pid when those + tasks fork. Also, when tasks with PIDs in set_event_pid exit, + their PIDs will be removed from the file. function-trace - The latency tracers will enable function tracing if this option is enabled (default it is). When @@ -904,8 +909,17 @@ x494] <- /root/a.out[+0x4a8] <- /lib/libc-2.7.so[+0x1e1a6] functions. This keeps the overhead of the tracer down when performing latency tests. - Note: Some tracers have their own options. They only appear - when the tracer is active. + display-graph - When set, the latency tracers (irqsoff, wakeup, etc) will + use function graph tracing instead of function tracing. + + stacktrace - This is one of the options that changes the trace + itself. When a trace is recorded, so is the stack + of functions. This allows for back traces of + trace sites. + + Note: Some tracers have their own options. They only appear in this + file when the tracer is active. They always appear in the + options directory. From 08d43a5fa063e03c860f2f391a30c388bcbc948e Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 10 Dec 2015 12:50:50 -0600 Subject: [PATCH 05/45] tracing: Add lock-free tracing_map Add tracing_map, a special-purpose lock-free map for tracing. tracing_map is designed to aggregate or 'sum' one or more values associated with a specific object of type tracing_map_elt, which is associated by the map to a given key. It provides various hooks allowing per-tracer customization and is separated out into a separate file in order to allow it to be shared between multiple tracers, but isn't meant to be generally used outside of that context. The tracing_map implementation was inspired by lock-free map algorithms originated by Dr. Cliff Click: http://www.azulsystems.com/blog/cliff/2007-03-26-non-blocking-hashtable http://www.azulsystems.com/events/javaone_2007/2007_LockFreeHash.pdf Link: http://lkml.kernel.org/r/b43d68d1add33582a396f553c8ef705a33a6a748.1449767187.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/Kconfig | 13 + kernel/trace/Makefile | 1 + kernel/trace/tracing_map.c | 1058 ++++++++++++++++++++++++++++++++++++ kernel/trace/tracing_map.h | 282 ++++++++++ 4 files changed, 1354 insertions(+) create mode 100644 kernel/trace/tracing_map.c create mode 100644 kernel/trace/tracing_map.h diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index e45db6b0d878..48b732943e0e 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -528,6 +528,19 @@ config MMIOTRACE See Documentation/trace/mmiotrace.txt. If you are not helping to develop drivers, say N. +config TRACING_MAP + bool + depends on ARCH_HAVE_NMI_SAFE_CMPXCHG + default n + help + tracing_map is a special-purpose lock-free map for tracing, + separated out as a stand-alone facility in order to allow it + to be shared between multiple tracers. It isn't meant to be + generally used outside of that context, and is normally + selected by tracers that use it. + + If in doubt, say N. + config MMIOTRACE_TEST tristate "Test module for mmiotrace" depends on MMIOTRACE && m diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 9b1044e936a6..4255c4057aaa 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -31,6 +31,7 @@ obj-$(CONFIG_TRACING) += trace_output.o obj-$(CONFIG_TRACING) += trace_seq.o obj-$(CONFIG_TRACING) += trace_stat.o obj-$(CONFIG_TRACING) += trace_printk.o +obj-$(CONFIG_TRACING_MAP) += tracing_map.o obj-$(CONFIG_CONTEXT_SWITCH_TRACER) += trace_sched_switch.o obj-$(CONFIG_FUNCTION_TRACER) += trace_functions.o obj-$(CONFIG_IRQSOFF_TRACER) += trace_irqsoff.o diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c new file mode 100644 index 000000000000..dd6401dd145e --- /dev/null +++ b/kernel/trace/tracing_map.c @@ -0,0 +1,1058 @@ +/* + * tracing_map - lock-free map for tracing + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * Copyright (C) 2015 Tom Zanussi + * + * tracing_map implementation inspired by lock-free map algorithms + * originated by Dr. Cliff Click: + * + * http://www.azulsystems.com/blog/cliff/2007-03-26-non-blocking-hashtable + * http://www.azulsystems.com/events/javaone_2007/2007_LockFreeHash.pdf + */ + +#include +#include +#include +#include + +#include "tracing_map.h" +#include "trace.h" + +/* + * NOTE: For a detailed description of the data structures used by + * these functions (such as tracing_map_elt) please see the overview + * of tracing_map data structures at the beginning of tracing_map.h. + */ + +/** + * tracing_map_update_sum - Add a value to a tracing_map_elt's sum field + * @elt: The tracing_map_elt + * @i: The index of the given sum associated with the tracing_map_elt + * @n: The value to add to the sum + * + * Add n to sum i associated with the specified tracing_map_elt + * instance. The index i is the index returned by the call to + * tracing_map_add_sum_field() when the tracing map was set up. + */ +void tracing_map_update_sum(struct tracing_map_elt *elt, unsigned int i, u64 n) +{ + atomic64_add(n, &elt->fields[i].sum); +} + +/** + * tracing_map_read_sum - Return the value of a tracing_map_elt's sum field + * @elt: The tracing_map_elt + * @i: The index of the given sum associated with the tracing_map_elt + * + * Retrieve the value of the sum i associated with the specified + * tracing_map_elt instance. The index i is the index returned by the + * call to tracing_map_add_sum_field() when the tracing map was set + * up. + * + * Return: The sum associated with field i for elt. + */ +u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i) +{ + return (u64)atomic64_read(&elt->fields[i].sum); +} + +int tracing_map_cmp_string(void *val_a, void *val_b) +{ + char *a = val_a; + char *b = val_b; + + return strcmp(a, b); +} + +int tracing_map_cmp_none(void *val_a, void *val_b) +{ + return 0; +} + +static int tracing_map_cmp_atomic64(void *val_a, void *val_b) +{ + u64 a = atomic64_read((atomic64_t *)val_a); + u64 b = atomic64_read((atomic64_t *)val_b); + + return (a > b) ? 1 : ((a < b) ? -1 : 0); +} + +#define DEFINE_TRACING_MAP_CMP_FN(type) \ +static int tracing_map_cmp_##type(void *val_a, void *val_b) \ +{ \ + type a = *(type *)val_a; \ + type b = *(type *)val_b; \ + \ + return (a > b) ? 1 : ((a < b) ? -1 : 0); \ +} + +DEFINE_TRACING_MAP_CMP_FN(s64); +DEFINE_TRACING_MAP_CMP_FN(u64); +DEFINE_TRACING_MAP_CMP_FN(s32); +DEFINE_TRACING_MAP_CMP_FN(u32); +DEFINE_TRACING_MAP_CMP_FN(s16); +DEFINE_TRACING_MAP_CMP_FN(u16); +DEFINE_TRACING_MAP_CMP_FN(s8); +DEFINE_TRACING_MAP_CMP_FN(u8); + +tracing_map_cmp_fn_t tracing_map_cmp_num(int field_size, + int field_is_signed) +{ + tracing_map_cmp_fn_t fn = tracing_map_cmp_none; + + switch (field_size) { + case 8: + if (field_is_signed) + fn = tracing_map_cmp_s64; + else + fn = tracing_map_cmp_u64; + break; + case 4: + if (field_is_signed) + fn = tracing_map_cmp_s32; + else + fn = tracing_map_cmp_u32; + break; + case 2: + if (field_is_signed) + fn = tracing_map_cmp_s16; + else + fn = tracing_map_cmp_u16; + break; + case 1: + if (field_is_signed) + fn = tracing_map_cmp_s8; + else + fn = tracing_map_cmp_u8; + break; + } + + return fn; +} + +static int tracing_map_add_field(struct tracing_map *map, + tracing_map_cmp_fn_t cmp_fn) +{ + int ret = -EINVAL; + + if (map->n_fields < TRACING_MAP_FIELDS_MAX) { + ret = map->n_fields; + map->fields[map->n_fields++].cmp_fn = cmp_fn; + } + + return ret; +} + +/** + * tracing_map_add_sum_field - Add a field describing a tracing_map sum + * @map: The tracing_map + * + * Add a sum field to the key and return the index identifying it in + * the map and associated tracing_map_elts. This is the index used + * for instance to update a sum for a particular tracing_map_elt using + * tracing_map_update_sum() or reading it via tracing_map_read_sum(). + * + * Return: The index identifying the field in the map and associated + * tracing_map_elts. + */ +int tracing_map_add_sum_field(struct tracing_map *map) +{ + return tracing_map_add_field(map, tracing_map_cmp_atomic64); +} + +/** + * tracing_map_add_key_field - Add a field describing a tracing_map key + * @map: The tracing_map + * @offset: The offset within the key + * @cmp_fn: The comparison function that will be used to sort on the key + * + * Let the map know there is a key and that if it's used as a sort key + * to use cmp_fn. + * + * A key can be a subset of a compound key; for that purpose, the + * offset param is used to describe where within the the compound key + * the key referenced by this key field resides. + * + * Return: The index identifying the field in the map and associated + * tracing_map_elts. + */ +int tracing_map_add_key_field(struct tracing_map *map, + unsigned int offset, + tracing_map_cmp_fn_t cmp_fn) + +{ + int idx = tracing_map_add_field(map, cmp_fn); + + if (idx < 0) + return idx; + + map->fields[idx].offset = offset; + + map->key_idx[map->n_keys++] = idx; + + return idx; +} + +void tracing_map_array_clear(struct tracing_map_array *a) +{ + unsigned int i; + + if (!a->pages) + return; + + for (i = 0; i < a->n_pages; i++) + memset(a->pages[i], 0, PAGE_SIZE); +} + +void tracing_map_array_free(struct tracing_map_array *a) +{ + unsigned int i; + + if (!a) + return; + + if (!a->pages) { + kfree(a); + return; + } + + for (i = 0; i < a->n_pages; i++) { + if (!a->pages[i]) + break; + free_page((unsigned long)a->pages[i]); + } +} + +struct tracing_map_array *tracing_map_array_alloc(unsigned int n_elts, + unsigned int entry_size) +{ + struct tracing_map_array *a; + unsigned int i; + + a = kzalloc(sizeof(*a), GFP_KERNEL); + if (!a) + return NULL; + + a->entry_size_shift = fls(roundup_pow_of_two(entry_size) - 1); + a->entries_per_page = PAGE_SIZE / (1 << a->entry_size_shift); + a->n_pages = n_elts / a->entries_per_page; + if (!a->n_pages) + a->n_pages = 1; + a->entry_shift = fls(a->entries_per_page) - 1; + a->entry_mask = (1 << a->entry_shift) - 1; + + a->pages = kcalloc(a->n_pages, sizeof(void *), GFP_KERNEL); + if (!a->pages) + goto free; + + for (i = 0; i < a->n_pages; i++) { + a->pages[i] = (void *)get_zeroed_page(GFP_KERNEL); + if (!a->pages[i]) + goto free; + } + out: + return a; + free: + tracing_map_array_free(a); + a = NULL; + + goto out; +} + +static void tracing_map_elt_clear(struct tracing_map_elt *elt) +{ + unsigned i; + + for (i = 0; i < elt->map->n_fields; i++) + if (elt->fields[i].cmp_fn == tracing_map_cmp_atomic64) + atomic64_set(&elt->fields[i].sum, 0); + + if (elt->map->ops && elt->map->ops->elt_clear) + elt->map->ops->elt_clear(elt); +} + +static void tracing_map_elt_init_fields(struct tracing_map_elt *elt) +{ + unsigned int i; + + tracing_map_elt_clear(elt); + + for (i = 0; i < elt->map->n_fields; i++) { + elt->fields[i].cmp_fn = elt->map->fields[i].cmp_fn; + + if (elt->fields[i].cmp_fn != tracing_map_cmp_atomic64) + elt->fields[i].offset = elt->map->fields[i].offset; + } +} + +static void tracing_map_elt_free(struct tracing_map_elt *elt) +{ + if (!elt) + return; + + if (elt->map->ops && elt->map->ops->elt_free) + elt->map->ops->elt_free(elt); + kfree(elt->fields); + kfree(elt->key); + kfree(elt); +} + +static struct tracing_map_elt *tracing_map_elt_alloc(struct tracing_map *map) +{ + struct tracing_map_elt *elt; + int err = 0; + + elt = kzalloc(sizeof(*elt), GFP_KERNEL); + if (!elt) + return ERR_PTR(-ENOMEM); + + elt->map = map; + + elt->key = kzalloc(map->key_size, GFP_KERNEL); + if (!elt->key) { + err = -ENOMEM; + goto free; + } + + elt->fields = kcalloc(map->n_fields, sizeof(*elt->fields), GFP_KERNEL); + if (!elt->fields) { + err = -ENOMEM; + goto free; + } + + tracing_map_elt_init_fields(elt); + + if (map->ops && map->ops->elt_alloc) { + err = map->ops->elt_alloc(elt); + if (err) + goto free; + } + return elt; + free: + tracing_map_elt_free(elt); + + return ERR_PTR(err); +} + +static struct tracing_map_elt *get_free_elt(struct tracing_map *map) +{ + struct tracing_map_elt *elt = NULL; + int idx; + + idx = atomic_inc_return(&map->next_elt); + if (idx < map->max_elts) { + elt = *(TRACING_MAP_ELT(map->elts, idx)); + if (map->ops && map->ops->elt_init) + map->ops->elt_init(elt); + } + + return elt; +} + +static void tracing_map_free_elts(struct tracing_map *map) +{ + unsigned int i; + + if (!map->elts) + return; + + for (i = 0; i < map->max_elts; i++) + tracing_map_elt_free(*(TRACING_MAP_ELT(map->elts, i))); + + tracing_map_array_free(map->elts); +} + +static int tracing_map_alloc_elts(struct tracing_map *map) +{ + unsigned int i; + + map->elts = tracing_map_array_alloc(map->max_elts, + sizeof(struct tracing_map_elt *)); + if (!map->elts) + return -ENOMEM; + + for (i = 0; i < map->max_elts; i++) { + *(TRACING_MAP_ELT(map->elts, i)) = tracing_map_elt_alloc(map); + if (!(*(TRACING_MAP_ELT(map->elts, i)))) { + tracing_map_free_elts(map); + + return -ENOMEM; + } + } + + return 0; +} + +static inline bool keys_match(void *key, void *test_key, unsigned key_size) +{ + bool match = true; + + if (memcmp(key, test_key, key_size)) + match = false; + + return match; +} + +static inline struct tracing_map_elt * +__tracing_map_insert(struct tracing_map *map, void *key, bool lookup_only) +{ + u32 idx, key_hash, test_key; + struct tracing_map_entry *entry; + + key_hash = jhash(key, map->key_size, 0); + if (key_hash == 0) + key_hash = 1; + idx = key_hash >> (32 - (map->map_bits + 1)); + + while (1) { + idx &= (map->map_size - 1); + entry = TRACING_MAP_ENTRY(map->map, idx); + test_key = entry->key; + + if (test_key && test_key == key_hash && entry->val && + keys_match(key, entry->val->key, map->key_size)) { + atomic64_inc(&map->hits); + return entry->val; + } + + if (!test_key) { + if (lookup_only) + break; + + if (!cmpxchg(&entry->key, 0, key_hash)) { + struct tracing_map_elt *elt; + + elt = get_free_elt(map); + if (!elt) { + atomic64_inc(&map->drops); + entry->key = 0; + break; + } + + memcpy(elt->key, key, map->key_size); + entry->val = elt; + atomic64_inc(&map->hits); + + return entry->val; + } + } + + idx++; + } + + return NULL; +} + +/** + * tracing_map_insert - Insert key and/or retrieve val from a tracing_map + * @map: The tracing_map to insert into + * @key: The key to insert + * + * Inserts a key into a tracing_map and creates and returns a new + * tracing_map_elt for it, or if the key has already been inserted by + * a previous call, returns the tracing_map_elt already associated + * with it. When the map was created, the number of elements to be + * allocated for the map was specified (internally maintained as + * 'max_elts' in struct tracing_map), and that number of + * tracing_map_elts was created by tracing_map_init(). This is the + * pre-allocated pool of tracing_map_elts that tracing_map_insert() + * will allocate from when adding new keys. Once that pool is + * exhausted, tracing_map_insert() is useless and will return NULL to + * signal that state. There are two user-visible tracing_map + * variables, 'hits' and 'drops', which are updated by this function. + * Every time an element is either successfully inserted or retrieved, + * the 'hits' value is incrememented. Every time an element insertion + * fails, the 'drops' value is incremented. + * + * This is a lock-free tracing map insertion function implementing a + * modified form of Cliff Click's basic insertion algorithm. It + * requires the table size be a power of two. To prevent any + * possibility of an infinite loop we always make the internal table + * size double the size of the requested table size (max_elts * 2). + * Likewise, we never reuse a slot or resize or delete elements - when + * we've reached max_elts entries, we simply return NULL once we've + * run out of entries. Readers can at any point in time traverse the + * tracing map and safely access the key/val pairs. + * + * Return: the tracing_map_elt pointer val associated with the key. + * If this was a newly inserted key, the val will be a newly allocated + * and associated tracing_map_elt pointer val. If the key wasn't + * found and the pool of tracing_map_elts has been exhausted, NULL is + * returned and no further insertions will succeed. + */ +struct tracing_map_elt *tracing_map_insert(struct tracing_map *map, void *key) +{ + return __tracing_map_insert(map, key, false); +} + +/** + * tracing_map_lookup - Retrieve val from a tracing_map + * @map: The tracing_map to perform the lookup on + * @key: The key to look up + * + * Looks up key in tracing_map and if found returns the matching + * tracing_map_elt. This is a lock-free lookup; see + * tracing_map_insert() for details on tracing_map and how it works. + * Every time an element is retrieved, the 'hits' value is + * incrememented. There is one user-visible tracing_map variable, + * 'hits', which is updated by this function. Every time an element + * is successfully retrieved, the 'hits' value is incrememented. The + * 'drops' value is never updated by this function. + * + * Return: the tracing_map_elt pointer val associated with the key. + * If the key wasn't found, NULL is returned. + */ +struct tracing_map_elt *tracing_map_lookup(struct tracing_map *map, void *key) +{ + return __tracing_map_insert(map, key, true); +} + +/** + * tracing_map_destroy - Destroy a tracing_map + * @map: The tracing_map to destroy + * + * Frees a tracing_map along with its associated array of + * tracing_map_elts. + * + * Callers should make sure there are no readers or writers actively + * reading or inserting into the map before calling this. + */ +void tracing_map_destroy(struct tracing_map *map) +{ + if (!map) + return; + + tracing_map_free_elts(map); + + tracing_map_array_free(map->map); + kfree(map); +} + +/** + * tracing_map_clear - Clear a tracing_map + * @map: The tracing_map to clear + * + * Resets the tracing map to a cleared or initial state. The + * tracing_map_elts are all cleared, and the array of struct + * tracing_map_entry is reset to an initialized state. + * + * Callers should make sure there are no writers actively inserting + * into the map before calling this. + */ +void tracing_map_clear(struct tracing_map *map) +{ + unsigned int i; + + atomic_set(&map->next_elt, -1); + atomic64_set(&map->hits, 0); + atomic64_set(&map->drops, 0); + + tracing_map_array_clear(map->map); + + for (i = 0; i < map->max_elts; i++) + tracing_map_elt_clear(*(TRACING_MAP_ELT(map->elts, i))); +} + +static void set_sort_key(struct tracing_map *map, + struct tracing_map_sort_key *sort_key) +{ + map->sort_key = *sort_key; +} + +/** + * tracing_map_create - Create a lock-free map and element pool + * @map_bits: The size of the map (2 ** map_bits) + * @key_size: The size of the key for the map in bytes + * @ops: Optional client-defined tracing_map_ops instance + * @private_data: Client data associated with the map + * + * Creates and sets up a map to contain 2 ** map_bits number of + * elements (internally maintained as 'max_elts' in struct + * tracing_map). Before using, map fields should be added to the map + * with tracing_map_add_sum_field() and tracing_map_add_key_field(). + * tracing_map_init() should then be called to allocate the array of + * tracing_map_elts, in order to avoid allocating anything in the map + * insertion path. The user-specified map size reflects the maximum + * number of elements that can be contained in the table requested by + * the user - internally we double that in order to keep the table + * sparse and keep collisions manageable. + * + * A tracing_map is a special-purpose map designed to aggregate or + * 'sum' one or more values associated with a specific object of type + * tracing_map_elt, which is attached by the map to a given key. + * + * tracing_map_create() sets up the map itself, and provides + * operations for inserting tracing_map_elts, but doesn't allocate the + * tracing_map_elts themselves, or provide a means for describing the + * keys or sums associated with the tracing_map_elts. All + * tracing_map_elts for a given map have the same set of sums and + * keys, which are defined by the client using the functions + * tracing_map_add_key_field() and tracing_map_add_sum_field(). Once + * the fields are defined, the pool of elements allocated for the map + * can be created, which occurs when the client code calls + * tracing_map_init(). + * + * When tracing_map_init() returns, tracing_map_elt elements can be + * inserted into the map using tracing_map_insert(). When called, + * tracing_map_insert() grabs a free tracing_map_elt from the pool, or + * finds an existing match in the map and in either case returns it. + * The client can then use tracing_map_update_sum() and + * tracing_map_read_sum() to update or read a given sum field for the + * tracing_map_elt. + * + * The client can at any point retrieve and traverse the current set + * of inserted tracing_map_elts in a tracing_map, via + * tracing_map_sort_entries(). Sorting can be done on any field, + * including keys. + * + * See tracing_map.h for a description of tracing_map_ops. + * + * Return: the tracing_map pointer if successful, ERR_PTR if not. + */ +struct tracing_map *tracing_map_create(unsigned int map_bits, + unsigned int key_size, + const struct tracing_map_ops *ops, + void *private_data) +{ + struct tracing_map *map; + unsigned int i; + + if (map_bits < TRACING_MAP_BITS_MIN || + map_bits > TRACING_MAP_BITS_MAX) + return ERR_PTR(-EINVAL); + + map = kzalloc(sizeof(*map), GFP_KERNEL); + if (!map) + return ERR_PTR(-ENOMEM); + + map->map_bits = map_bits; + map->max_elts = (1 << map_bits); + atomic_set(&map->next_elt, -1); + + map->map_size = (1 << (map_bits + 1)); + map->ops = ops; + + map->private_data = private_data; + + map->map = tracing_map_array_alloc(map->map_size, + sizeof(struct tracing_map_entry)); + if (!map->map) + goto free; + + map->key_size = key_size; + for (i = 0; i < TRACING_MAP_KEYS_MAX; i++) + map->key_idx[i] = -1; + out: + return map; + free: + tracing_map_destroy(map); + map = ERR_PTR(-ENOMEM); + + goto out; +} + +/** + * tracing_map_init - Allocate and clear a map's tracing_map_elts + * @map: The tracing_map to initialize + * + * Allocates a clears a pool of tracing_map_elts equal to the + * user-specified size of 2 ** map_bits (internally maintained as + * 'max_elts' in struct tracing_map). Before using, the map fields + * should be added to the map with tracing_map_add_sum_field() and + * tracing_map_add_key_field(). tracing_map_init() should then be + * called to allocate the array of tracing_map_elts, in order to avoid + * allocating anything in the map insertion path. The user-specified + * map size reflects the max number of elements requested by the user + * - internally we double that in order to keep the table sparse and + * keep collisions manageable. + * + * See tracing_map.h for a description of tracing_map_ops. + * + * Return: the tracing_map pointer if successful, ERR_PTR if not. + */ +int tracing_map_init(struct tracing_map *map) +{ + int err; + + if (map->n_fields < 2) + return -EINVAL; /* need at least 1 key and 1 val */ + + err = tracing_map_alloc_elts(map); + if (err) + return err; + + tracing_map_clear(map); + + return err; +} + +static int cmp_entries_dup(const struct tracing_map_sort_entry **a, + const struct tracing_map_sort_entry **b) +{ + int ret = 0; + + if (memcmp((*a)->key, (*b)->key, (*a)->elt->map->key_size)) + ret = 1; + + return ret; +} + +static int cmp_entries_sum(const struct tracing_map_sort_entry **a, + const struct tracing_map_sort_entry **b) +{ + const struct tracing_map_elt *elt_a, *elt_b; + struct tracing_map_sort_key *sort_key; + struct tracing_map_field *field; + tracing_map_cmp_fn_t cmp_fn; + void *val_a, *val_b; + int ret = 0; + + elt_a = (*a)->elt; + elt_b = (*b)->elt; + + sort_key = &elt_a->map->sort_key; + + field = &elt_a->fields[sort_key->field_idx]; + cmp_fn = field->cmp_fn; + + val_a = &elt_a->fields[sort_key->field_idx].sum; + val_b = &elt_b->fields[sort_key->field_idx].sum; + + ret = cmp_fn(val_a, val_b); + if (sort_key->descending) + ret = -ret; + + return ret; +} + +static int cmp_entries_key(const struct tracing_map_sort_entry **a, + const struct tracing_map_sort_entry **b) +{ + const struct tracing_map_elt *elt_a, *elt_b; + struct tracing_map_sort_key *sort_key; + struct tracing_map_field *field; + tracing_map_cmp_fn_t cmp_fn; + void *val_a, *val_b; + int ret = 0; + + elt_a = (*a)->elt; + elt_b = (*b)->elt; + + sort_key = &elt_a->map->sort_key; + + field = &elt_a->fields[sort_key->field_idx]; + + cmp_fn = field->cmp_fn; + + val_a = elt_a->key + field->offset; + val_b = elt_b->key + field->offset; + + ret = cmp_fn(val_a, val_b); + if (sort_key->descending) + ret = -ret; + + return ret; +} + +static void destroy_sort_entry(struct tracing_map_sort_entry *entry) +{ + if (!entry) + return; + + if (entry->elt_copied) + tracing_map_elt_free(entry->elt); + + kfree(entry); +} + +/** + * tracing_map_destroy_sort_entries - Destroy an array of sort entries + * @entries: The entries to destroy + * @n_entries: The number of entries in the array + * + * Destroy the elements returned by a tracing_map_sort_entries() call. + */ +void tracing_map_destroy_sort_entries(struct tracing_map_sort_entry **entries, + unsigned int n_entries) +{ + unsigned int i; + + for (i = 0; i < n_entries; i++) + destroy_sort_entry(entries[i]); + + vfree(entries); +} + +static struct tracing_map_sort_entry * +create_sort_entry(void *key, struct tracing_map_elt *elt) +{ + struct tracing_map_sort_entry *sort_entry; + + sort_entry = kzalloc(sizeof(*sort_entry), GFP_KERNEL); + if (!sort_entry) + return NULL; + + sort_entry->key = key; + sort_entry->elt = elt; + + return sort_entry; +} + +static struct tracing_map_elt *copy_elt(struct tracing_map_elt *elt) +{ + struct tracing_map_elt *dup_elt; + unsigned int i; + + dup_elt = tracing_map_elt_alloc(elt->map); + if (!dup_elt) + return NULL; + + if (elt->map->ops && elt->map->ops->elt_copy) + elt->map->ops->elt_copy(dup_elt, elt); + + dup_elt->private_data = elt->private_data; + memcpy(dup_elt->key, elt->key, elt->map->key_size); + + for (i = 0; i < elt->map->n_fields; i++) { + atomic64_set(&dup_elt->fields[i].sum, + atomic64_read(&elt->fields[i].sum)); + dup_elt->fields[i].cmp_fn = elt->fields[i].cmp_fn; + } + + return dup_elt; +} + +static int merge_dup(struct tracing_map_sort_entry **sort_entries, + unsigned int target, unsigned int dup) +{ + struct tracing_map_elt *target_elt, *elt; + bool first_dup = (target - dup) == 1; + int i; + + if (first_dup) { + elt = sort_entries[target]->elt; + target_elt = copy_elt(elt); + if (!target_elt) + return -ENOMEM; + sort_entries[target]->elt = target_elt; + sort_entries[target]->elt_copied = true; + } else + target_elt = sort_entries[target]->elt; + + elt = sort_entries[dup]->elt; + + for (i = 0; i < elt->map->n_fields; i++) + atomic64_add(atomic64_read(&elt->fields[i].sum), + &target_elt->fields[i].sum); + + sort_entries[dup]->dup = true; + + return 0; +} + +static int merge_dups(struct tracing_map_sort_entry **sort_entries, + int n_entries, unsigned int key_size) +{ + unsigned int dups = 0, total_dups = 0; + int err, i, j; + void *key; + + if (n_entries < 2) + return total_dups; + + sort(sort_entries, n_entries, sizeof(struct tracing_map_sort_entry *), + (int (*)(const void *, const void *))cmp_entries_dup, NULL); + + key = sort_entries[0]->key; + for (i = 1; i < n_entries; i++) { + if (!memcmp(sort_entries[i]->key, key, key_size)) { + dups++; total_dups++; + err = merge_dup(sort_entries, i - dups, i); + if (err) + return err; + continue; + } + key = sort_entries[i]->key; + dups = 0; + } + + if (!total_dups) + return total_dups; + + for (i = 0, j = 0; i < n_entries; i++) { + if (!sort_entries[i]->dup) { + sort_entries[j] = sort_entries[i]; + if (j++ != i) + sort_entries[i] = NULL; + } else { + destroy_sort_entry(sort_entries[i]); + sort_entries[i] = NULL; + } + } + + return total_dups; +} + +static bool is_key(struct tracing_map *map, unsigned int field_idx) +{ + unsigned int i; + + for (i = 0; i < map->n_keys; i++) + if (map->key_idx[i] == field_idx) + return true; + return false; +} + +static void sort_secondary(struct tracing_map *map, + const struct tracing_map_sort_entry **entries, + unsigned int n_entries, + struct tracing_map_sort_key *primary_key, + struct tracing_map_sort_key *secondary_key) +{ + int (*primary_fn)(const struct tracing_map_sort_entry **, + const struct tracing_map_sort_entry **); + int (*secondary_fn)(const struct tracing_map_sort_entry **, + const struct tracing_map_sort_entry **); + unsigned i, start = 0, n_sub = 1; + + if (is_key(map, primary_key->field_idx)) + primary_fn = cmp_entries_key; + else + primary_fn = cmp_entries_sum; + + if (is_key(map, secondary_key->field_idx)) + secondary_fn = cmp_entries_key; + else + secondary_fn = cmp_entries_sum; + + for (i = 0; i < n_entries - 1; i++) { + const struct tracing_map_sort_entry **a = &entries[i]; + const struct tracing_map_sort_entry **b = &entries[i + 1]; + + if (primary_fn(a, b) == 0) { + n_sub++; + if (i < n_entries - 2) + continue; + } + + if (n_sub < 2) { + start = i + 1; + n_sub = 1; + continue; + } + + set_sort_key(map, secondary_key); + sort(&entries[start], n_sub, + sizeof(struct tracing_map_sort_entry *), + (int (*)(const void *, const void *))secondary_fn, NULL); + set_sort_key(map, primary_key); + + start = i + 1; + n_sub = 1; + } +} + +/** + * tracing_map_sort_entries - Sort the current set of tracing_map_elts in a map + * @map: The tracing_map + * @sort_key: The sort key to use for sorting + * @sort_entries: outval: pointer to allocated and sorted array of entries + * + * tracing_map_sort_entries() sorts the current set of entries in the + * map and returns the list of tracing_map_sort_entries containing + * them to the client in the sort_entries param. The client can + * access the struct tracing_map_elt element of interest directly as + * the 'elt' field of a returned struct tracing_map_sort_entry object. + * + * The sort_key has only two fields: idx and descending. 'idx' refers + * to the index of the field added via tracing_map_add_sum_field() or + * tracing_map_add_key_field() when the tracing_map was initialized. + * 'descending' is a flag that if set reverses the sort order, which + * by default is ascending. + * + * The client should not hold on to the returned array but should use + * it and call tracing_map_destroy_sort_entries() when done. + * + * Return: the number of sort_entries in the struct tracing_map_sort_entry + * array, negative on error + */ +int tracing_map_sort_entries(struct tracing_map *map, + struct tracing_map_sort_key *sort_keys, + unsigned int n_sort_keys, + struct tracing_map_sort_entry ***sort_entries) +{ + int (*cmp_entries_fn)(const struct tracing_map_sort_entry **, + const struct tracing_map_sort_entry **); + struct tracing_map_sort_entry *sort_entry, **entries; + int i, n_entries, ret; + + entries = vmalloc(map->max_elts * sizeof(sort_entry)); + if (!entries) + return -ENOMEM; + + for (i = 0, n_entries = 0; i < map->map_size; i++) { + struct tracing_map_entry *entry; + + entry = TRACING_MAP_ENTRY(map->map, i); + + if (!entry->key || !entry->val) + continue; + + entries[n_entries] = create_sort_entry(entry->val->key, + entry->val); + if (!entries[n_entries++]) { + ret = -ENOMEM; + goto free; + } + } + + if (n_entries == 0) { + ret = 0; + goto free; + } + + if (n_entries == 1) { + *sort_entries = entries; + return 1; + } + + ret = merge_dups(entries, n_entries, map->key_size); + if (ret < 0) + goto free; + n_entries -= ret; + + if (is_key(map, sort_keys[0].field_idx)) + cmp_entries_fn = cmp_entries_key; + else + cmp_entries_fn = cmp_entries_sum; + + set_sort_key(map, &sort_keys[0]); + + sort(entries, n_entries, sizeof(struct tracing_map_sort_entry *), + (int (*)(const void *, const void *))cmp_entries_fn, NULL); + + if (n_sort_keys > 1) + sort_secondary(map, + (const struct tracing_map_sort_entry **)entries, + n_entries, + &sort_keys[0], + &sort_keys[1]); + + *sort_entries = entries; + + return n_entries; + free: + tracing_map_destroy_sort_entries(entries, n_entries); + + return ret; +} diff --git a/kernel/trace/tracing_map.h b/kernel/trace/tracing_map.h new file mode 100644 index 000000000000..75718255a8ad --- /dev/null +++ b/kernel/trace/tracing_map.h @@ -0,0 +1,282 @@ +#ifndef __TRACING_MAP_H +#define __TRACING_MAP_H + +#define TRACING_MAP_BITS_DEFAULT 11 +#define TRACING_MAP_BITS_MAX 17 +#define TRACING_MAP_BITS_MIN 7 + +#define TRACING_MAP_FIELDS_MAX 4 +#define TRACING_MAP_KEYS_MAX 2 + +#define TRACING_MAP_SORT_KEYS_MAX 2 + +typedef int (*tracing_map_cmp_fn_t) (void *val_a, void *val_b); + +/* + * This is an overview of the tracing_map data structures and how they + * relate to the tracing_map API. The details of the algorithms + * aren't discussed here - this is just a general overview of the data + * structures and how they interact with the API. + * + * The central data structure of the tracing_map is an initially + * zeroed array of struct tracing_map_entry (stored in the map field + * of struct tracing_map). tracing_map_entry is a very simple data + * structure containing only two fields: a 32-bit unsigned 'key' + * variable and a pointer named 'val'. This array of struct + * tracing_map_entry is essentially a hash table which will be + * modified by a single function, tracing_map_insert(), but which can + * be traversed and read by a user at any time (though the user does + * this indirectly via an array of tracing_map_sort_entry - see the + * explanation of that data structure in the discussion of the + * sorting-related data structures below). + * + * The central function of the tracing_map API is + * tracing_map_insert(). tracing_map_insert() hashes the + * arbitrarily-sized key passed into it into a 32-bit unsigned key. + * It then uses this key, truncated to the array size, as an index + * into the array of tracing_map_entries. If the value of the 'key' + * field of the tracing_map_entry found at that location is 0, then + * that entry is considered to be free and can be claimed, by + * replacing the 0 in the 'key' field of the tracing_map_entry with + * the new 32-bit hashed key. Once claimed, that tracing_map_entry's + * 'val' field is then used to store a unique element which will be + * forever associated with that 32-bit hashed key in the + * tracing_map_entry. + * + * That unique element now in the tracing_map_entry's 'val' field is + * an instance of tracing_map_elt, where 'elt' in the latter part of + * that variable name is short for 'element'. The purpose of a + * tracing_map_elt is to hold values specific to the the particular + * 32-bit hashed key it's assocated with. Things such as the unique + * set of aggregated sums associated with the 32-bit hashed key, along + * with a copy of the full key associated with the entry, and which + * was used to produce the 32-bit hashed key. + * + * When tracing_map_create() is called to create the tracing map, the + * user specifies (indirectly via the map_bits param, the details are + * unimportant for this discussion) the maximum number of elements + * that the map can hold (stored in the max_elts field of struct + * tracing_map). This is the maximum possible number of + * tracing_map_entries in the tracing_map_entry array which can be + * 'claimed' as described in the above discussion, and therefore is + * also the maximum number of tracing_map_elts that can be associated + * with the tracing_map_entry array in the tracing_map. Because of + * the way the insertion algorithm works, the size of the allocated + * tracing_map_entry array is always twice the maximum number of + * elements (2 * max_elts). This value is stored in the map_size + * field of struct tracing_map. + * + * Because tracing_map_insert() needs to work from any context, + * including from within the memory allocation functions themselves, + * both the tracing_map_entry array and a pool of max_elts + * tracing_map_elts are pre-allocated before any call is made to + * tracing_map_insert(). + * + * The tracing_map_entry array is allocated as a single block by + * tracing_map_create(). + * + * Because the tracing_map_elts are much larger objects and can't + * generally be allocated together as a single large array without + * failure, they're allocated individually, by tracing_map_init(). + * + * The pool of tracing_map_elts are allocated by tracing_map_init() + * rather than by tracing_map_create() because at the time + * tracing_map_create() is called, there isn't enough information to + * create the tracing_map_elts. Specifically,the user first needs to + * tell the tracing_map implementation how many fields the + * tracing_map_elts contain, and which types of fields they are (key + * or sum). The user does this via the tracing_map_add_sum_field() + * and tracing_map_add_key_field() functions, following which the user + * calls tracing_map_init() to finish up the tracing map setup. The + * array holding the pointers which make up the pre-allocated pool of + * tracing_map_elts is allocated as a single block and is stored in + * the elts field of struct tracing_map. + * + * There is also a set of structures used for sorting that might + * benefit from some minimal explanation. + * + * struct tracing_map_sort_key is used to drive the sort at any given + * time. By 'any given time' we mean that a different + * tracing_map_sort_key will be used at different times depending on + * whether the sort currently being performed is a primary or a + * secondary sort. + * + * The sort key is very simple, consisting of the field index of the + * tracing_map_elt field to sort on (which the user saved when adding + * the field), and whether the sort should be done in an ascending or + * descending order. + * + * For the convenience of the sorting code, a tracing_map_sort_entry + * is created for each tracing_map_elt, again individually allocated + * to avoid failures that might be expected if allocated as a single + * large array of struct tracing_map_sort_entry. + * tracing_map_sort_entry instances are the objects expected by the + * various internal sorting functions, and are also what the user + * ultimately receives after calling tracing_map_sort_entries(). + * Because it doesn't make sense for users to access an unordered and + * sparsely populated tracing_map directly, the + * tracing_map_sort_entries() function is provided so that users can + * retrieve a sorted list of all existing elements. In addition to + * the associated tracing_map_elt 'elt' field contained within the + * tracing_map_sort_entry, which is the object of interest to the + * user, tracing_map_sort_entry objects contain a number of additional + * fields which are used for caching and internal purposes and can + * safely be ignored. +*/ + +struct tracing_map_field { + tracing_map_cmp_fn_t cmp_fn; + union { + atomic64_t sum; + unsigned int offset; + }; +}; + +struct tracing_map_elt { + struct tracing_map *map; + struct tracing_map_field *fields; + void *key; + void *private_data; +}; + +struct tracing_map_entry { + u32 key; + struct tracing_map_elt *val; +}; + +struct tracing_map_sort_key { + unsigned int field_idx; + bool descending; +}; + +struct tracing_map_sort_entry { + void *key; + struct tracing_map_elt *elt; + bool elt_copied; + bool dup; +}; + +struct tracing_map_array { + unsigned int entries_per_page; + unsigned int entry_size_shift; + unsigned int entry_shift; + unsigned int entry_mask; + unsigned int n_pages; + void **pages; +}; + +#define TRACING_MAP_ARRAY_ELT(array, idx) \ + (array->pages[idx >> array->entry_shift] + \ + ((idx & array->entry_mask) << array->entry_size_shift)) + +#define TRACING_MAP_ENTRY(array, idx) \ + ((struct tracing_map_entry *)TRACING_MAP_ARRAY_ELT(array, idx)) + +#define TRACING_MAP_ELT(array, idx) \ + ((struct tracing_map_elt **)TRACING_MAP_ARRAY_ELT(array, idx)) + +struct tracing_map { + unsigned int key_size; + unsigned int map_bits; + unsigned int map_size; + unsigned int max_elts; + atomic_t next_elt; + struct tracing_map_array *elts; + struct tracing_map_array *map; + const struct tracing_map_ops *ops; + void *private_data; + struct tracing_map_field fields[TRACING_MAP_FIELDS_MAX]; + unsigned int n_fields; + int key_idx[TRACING_MAP_KEYS_MAX]; + unsigned int n_keys; + struct tracing_map_sort_key sort_key; + atomic64_t hits; + atomic64_t drops; +}; + +/** + * struct tracing_map_ops - callbacks for tracing_map + * + * The methods in this structure define callback functions for various + * operations on a tracing_map or objects related to a tracing_map. + * + * For a detailed description of tracing_map_elt objects please see + * the overview of tracing_map data structures at the beginning of + * this file. + * + * All the methods below are optional. + * + * @elt_alloc: When a tracing_map_elt is allocated, this function, if + * defined, will be called and gives clients the opportunity to + * allocate additional data and attach it to the element + * (tracing_map_elt->private_data is meant for that purpose). + * Element allocation occurs before tracing begins, when the + * tracing_map_init() call is made by client code. + * + * @elt_copy: At certain points in the lifetime of an element, it may + * need to be copied. The copy should include a copy of the + * client-allocated data, which can be copied into the 'to' + * element from the 'from' element. + * + * @elt_free: When a tracing_map_elt is freed, this function is called + * and allows client-allocated per-element data to be freed. + * + * @elt_clear: This callback allows per-element client-defined data to + * be cleared, if applicable. + * + * @elt_init: This callback allows per-element client-defined data to + * be initialized when used i.e. when the element is actually + * claimed by tracing_map_insert() in the context of the map + * insertion. + */ +struct tracing_map_ops { + int (*elt_alloc)(struct tracing_map_elt *elt); + void (*elt_copy)(struct tracing_map_elt *to, + struct tracing_map_elt *from); + void (*elt_free)(struct tracing_map_elt *elt); + void (*elt_clear)(struct tracing_map_elt *elt); + void (*elt_init)(struct tracing_map_elt *elt); +}; + +extern struct tracing_map * +tracing_map_create(unsigned int map_bits, + unsigned int key_size, + const struct tracing_map_ops *ops, + void *private_data); +extern int tracing_map_init(struct tracing_map *map); + +extern int tracing_map_add_sum_field(struct tracing_map *map); +extern int tracing_map_add_key_field(struct tracing_map *map, + unsigned int offset, + tracing_map_cmp_fn_t cmp_fn); + +extern void tracing_map_destroy(struct tracing_map *map); +extern void tracing_map_clear(struct tracing_map *map); + +extern struct tracing_map_elt * +tracing_map_insert(struct tracing_map *map, void *key); +extern struct tracing_map_elt * +tracing_map_lookup(struct tracing_map *map, void *key); + +extern tracing_map_cmp_fn_t tracing_map_cmp_num(int field_size, + int field_is_signed); +extern int tracing_map_cmp_string(void *val_a, void *val_b); +extern int tracing_map_cmp_none(void *val_a, void *val_b); + +extern void tracing_map_update_sum(struct tracing_map_elt *elt, + unsigned int i, u64 n); +extern u64 tracing_map_read_sum(struct tracing_map_elt *elt, unsigned int i); +extern void tracing_map_set_field_descr(struct tracing_map *map, + unsigned int i, + unsigned int key_offset, + tracing_map_cmp_fn_t cmp_fn); +extern int +tracing_map_sort_entries(struct tracing_map *map, + struct tracing_map_sort_key *sort_keys, + unsigned int n_sort_keys, + struct tracing_map_sort_entry ***sort_entries); + +extern void +tracing_map_destroy_sort_entries(struct tracing_map_sort_entry **entries, + unsigned int n_entries); +#endif /* __TRACING_MAP_H */ From 8d44f2f34fb50f40185ef6404b0047223a27ba82 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Fri, 19 Feb 2016 14:47:00 -0500 Subject: [PATCH 06/45] tracing: Fix TRACING_MAP Kconfig The config option for TRACING_MAP has "default n", which is not needed because the default of configs is 'n'. Also, since the TRACING_MAP has no config prompt, there's no reason to include "If in doubt, say N" in the help text. Fixed a typo in the comments of tracing_map.h. Signed-off-by: Steven Rostedt --- kernel/trace/Kconfig | 3 --- kernel/trace/tracing_map.h | 2 +- 2 files changed, 1 insertion(+), 4 deletions(-) diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index 48b732943e0e..d39556fd863a 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -531,7 +531,6 @@ config MMIOTRACE config TRACING_MAP bool depends on ARCH_HAVE_NMI_SAFE_CMPXCHG - default n help tracing_map is a special-purpose lock-free map for tracing, separated out as a stand-alone facility in order to allow it @@ -539,8 +538,6 @@ config TRACING_MAP generally used outside of that context, and is normally selected by tracers that use it. - If in doubt, say N. - config MMIOTRACE_TEST tristate "Test module for mmiotrace" depends on MMIOTRACE && m diff --git a/kernel/trace/tracing_map.h b/kernel/trace/tracing_map.h index 75718255a8ad..1f7eda548787 100644 --- a/kernel/trace/tracing_map.h +++ b/kernel/trace/tracing_map.h @@ -46,7 +46,7 @@ typedef int (*tracing_map_cmp_fn_t) (void *val_a, void *val_b); * That unique element now in the tracing_map_entry's 'val' field is * an instance of tracing_map_elt, where 'elt' in the latter part of * that variable name is short for 'element'. The purpose of a - * tracing_map_elt is to hold values specific to the the particular + * tracing_map_elt is to hold values specific to the particular * 32-bit hashed key it's assocated with. Things such as the unique * set of aggregated sums associated with the 32-bit hashed key, along * with a copy of the full key associated with the entry, and which From 3b772b96b8338bca2532839b2cd7802800e66037 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:41 -0600 Subject: [PATCH 07/45] tracing: Update some tracing_map constants and comments Make it clear exactly how many keys and values are supported through better defines, and add 1 to the vals count, since normally clients want support for at least a hitcount and two other values. Also, note the error return value for tracing_map_add_key/val_field() in the comments. Link: http://lkml.kernel.org/r/6696fa02ebc716aa344c27a571a2afaa25e5b4d4.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- kernel/trace/tracing_map.c | 4 ++-- kernel/trace/tracing_map.h | 5 +++-- 2 files changed, 5 insertions(+), 4 deletions(-) diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c index dd6401dd145e..e0f172932eca 100644 --- a/kernel/trace/tracing_map.c +++ b/kernel/trace/tracing_map.c @@ -163,7 +163,7 @@ static int tracing_map_add_field(struct tracing_map *map, * tracing_map_update_sum() or reading it via tracing_map_read_sum(). * * Return: The index identifying the field in the map and associated - * tracing_map_elts. + * tracing_map_elts, or -EINVAL on error. */ int tracing_map_add_sum_field(struct tracing_map *map) { @@ -184,7 +184,7 @@ int tracing_map_add_sum_field(struct tracing_map *map) * the key referenced by this key field resides. * * Return: The index identifying the field in the map and associated - * tracing_map_elts. + * tracing_map_elts, or -EINVAL on error. */ int tracing_map_add_key_field(struct tracing_map *map, unsigned int offset, diff --git a/kernel/trace/tracing_map.h b/kernel/trace/tracing_map.h index 1f7eda548787..618838f5f30a 100644 --- a/kernel/trace/tracing_map.h +++ b/kernel/trace/tracing_map.h @@ -5,9 +5,10 @@ #define TRACING_MAP_BITS_MAX 17 #define TRACING_MAP_BITS_MIN 7 -#define TRACING_MAP_FIELDS_MAX 4 #define TRACING_MAP_KEYS_MAX 2 - +#define TRACING_MAP_VALS_MAX 3 +#define TRACING_MAP_FIELDS_MAX (TRACING_MAP_KEYS_MAX + \ + TRACING_MAP_VALS_MAX) #define TRACING_MAP_SORT_KEYS_MAX 2 typedef int (*tracing_map_cmp_fn_t) (void *val_a, void *val_b); From 7ef224d1d0e3a1ade02d02c01ce1dcffb736d2c3 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:42 -0600 Subject: [PATCH 08/45] tracing: Add 'hist' event trigger command 'hist' triggers allow users to continually aggregate trace events, which can then be viewed afterwards by simply reading a 'hist' file containing the aggregation in a human-readable format. The basic idea is very simple and boils down to a mechanism whereby trace events, rather than being exhaustively dumped in raw form and viewed directly, are automatically 'compressed' into meaningful tables completely defined by the user. This is done strictly via single-line command-line commands and without the aid of any kind of programming language or interpreter. A surprising number of typical use cases can be accomplished by users via this simple mechanism. In fact, a large number of the tasks that users typically do using the more complicated script-based tracing tools, at least during the initial stages of an investigation, can be accomplished by simply specifying a set of keys and values to be used in the creation of a hash table. The Linux kernel trace event subsystem happens to provide an extensive list of keys and values ready-made for such a purpose in the form of the event format files associated with each trace event. By simply consulting the format file for field names of interest and by plugging them into the hist trigger command, users can create an endless number of useful aggregations to help with investigating various properties of the system. See Documentation/trace/events.txt for examples. hist triggers are implemented on top of the existing event trigger infrastructure, and as such are consistent with the existing triggers from a user's perspective as well. The basic syntax follows the existing trigger syntax. Users start an aggregation by writing a 'hist' trigger to the event of interest's trigger file: # echo hist:keys=xxx [ if filter] > event/trigger Once a hist trigger has been set up, by default it continually aggregates every matching event into a hash table using the event key and a value field named 'hitcount'. To view the aggregation at any point in time, simply read the 'hist' file in the same directory as the 'trigger' file: # cat event/hist The detailed syntax provides additional options for user control, and is described exhaustively in Documentation/trace/events.txt and in the virtual tracing/README file in the tracing subsystem. Link: http://lkml.kernel.org/r/72d263b5e1853fe9c314953b65833c3aa75479f2.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- include/linux/trace_events.h | 1 + kernel/trace/Kconfig | 16 + kernel/trace/Makefile | 1 + kernel/trace/trace.c | 17 + kernel/trace/trace.h | 7 + kernel/trace/trace_events.c | 4 + kernel/trace/trace_events_hist.c | 849 ++++++++++++++++++++++++++++ kernel/trace/trace_events_trigger.c | 1 + 8 files changed, 896 insertions(+) create mode 100644 kernel/trace/trace_events_hist.c diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 0810f81b6db2..404603720650 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -407,6 +407,7 @@ enum event_trigger_type { ETT_SNAPSHOT = (1 << 1), ETT_STACKTRACE = (1 << 2), ETT_EVENT_ENABLE = (1 << 3), + ETT_EVENT_HIST = (1 << 4), }; extern int filter_match_preds(struct event_filter *filter, void *rec); diff --git a/kernel/trace/Kconfig b/kernel/trace/Kconfig index d39556fd863a..fafeaf803bd0 100644 --- a/kernel/trace/Kconfig +++ b/kernel/trace/Kconfig @@ -538,6 +538,22 @@ config TRACING_MAP generally used outside of that context, and is normally selected by tracers that use it. +config HIST_TRIGGERS + bool "Histogram triggers" + depends on ARCH_HAVE_NMI_SAFE_CMPXCHG + select TRACING_MAP + default n + help + Hist triggers allow one or more arbitrary trace event fields + to be aggregated into hash tables and dumped to stdout by + reading a debugfs/tracefs file. They're useful for + gathering quick and dirty (though precise) summaries of + event activity as an initial guide for further investigation + using more advanced tools. + + See Documentation/trace/events.txt. + If in doubt, say N. + config MMIOTRACE_TEST tristate "Test module for mmiotrace" depends on MMIOTRACE && m diff --git a/kernel/trace/Makefile b/kernel/trace/Makefile index 4255c4057aaa..979e7bfbde7a 100644 --- a/kernel/trace/Makefile +++ b/kernel/trace/Makefile @@ -54,6 +54,7 @@ obj-$(CONFIG_EVENT_TRACING) += trace_event_perf.o endif obj-$(CONFIG_EVENT_TRACING) += trace_events_filter.o obj-$(CONFIG_EVENT_TRACING) += trace_events_trigger.o +obj-$(CONFIG_HIST_TRIGGERS) += trace_events_hist.o obj-$(CONFIG_BPF_EVENTS) += bpf_trace.o obj-$(CONFIG_KPROBE_EVENT) += trace_kprobe.o obj-$(CONFIG_TRACEPOINTS) += power-traces.o diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0d12dbde8399..6cf8fd03b028 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3812,6 +3812,9 @@ static const char readme_msg[] = #endif #ifdef CONFIG_TRACER_SNAPSHOT "\t\t snapshot\n" +#endif +#ifdef CONFIG_HIST_TRIGGERS + "\t\t hist (see below)\n" #endif "\t example: echo traceoff > events/block/block_unplug/trigger\n" "\t echo traceoff:3 > events/block/block_unplug/trigger\n" @@ -3828,6 +3831,20 @@ static const char readme_msg[] = "\t To remove a trigger with a count:\n" "\t echo '!:0 > //trigger\n" "\t Filters can be ignored when removing a trigger.\n" +#ifdef CONFIG_HIST_TRIGGERS + " hist trigger\t- If set, event hits are aggregated into a hash table\n" + "\t Format: hist:keys=\n" + "\t [:size=#entries]\n" + "\t [if ]\n\n" + "\t When a matching event is hit, an entry is added to a hash\n" + "\t table using the key named, and the value of a sum called\n" + "\t 'hitcount' is incremented. Keys correspond to fields in the\n" + "\t event's format description. Keys can be any field. The\n" + "\t 'size' parameter can be used to specify more or fewer than\n" + "\t the default 2048 entries for the hashtable size.\n\n" + "\t Reading the 'hist' file for the event will dump the hash\n" + "\t table in its entirety to stdout." +#endif ; static ssize_t diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 2525042760e6..505f8a45f426 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1162,6 +1162,13 @@ extern struct mutex event_mutex; extern struct list_head ftrace_events; extern const struct file_operations event_trigger_fops; +extern const struct file_operations event_hist_fops; + +#ifdef CONFIG_HIST_TRIGGERS +extern int register_trigger_hist_cmd(void); +#else +static inline int register_trigger_hist_cmd(void) { return 0; } +#endif extern int register_trigger_cmds(void); extern void clear_event_triggers(struct trace_array *tr); diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index add81dff7520..e7cb983ee93c 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -2141,6 +2141,10 @@ event_create_dir(struct dentry *parent, struct trace_event_file *file) trace_create_file("trigger", 0644, file->dir, file, &event_trigger_fops); +#ifdef CONFIG_HIST_TRIGGERS + trace_create_file("hist", 0444, file->dir, file, + &event_hist_fops); +#endif trace_create_file("format", 0444, file->dir, call, &ftrace_event_format_fops); diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c new file mode 100644 index 000000000000..23b45e462117 --- /dev/null +++ b/kernel/trace/trace_events_hist.c @@ -0,0 +1,849 @@ +/* + * trace_events_hist - trace event hist triggers + * + * This program is free software; you can redistribute it and/or modify + * it under the terms of the GNU General Public License as published by + * the Free Software Foundation; either version 2 of the License, or + * (at your option) any later version. + * + * This program is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the + * GNU General Public License for more details. + * + * Copyright (C) 2015 Tom Zanussi + */ + +#include +#include +#include +#include +#include + +#include "tracing_map.h" +#include "trace.h" + +struct hist_field; + +typedef u64 (*hist_field_fn_t) (struct hist_field *field, void *event); + +struct hist_field { + struct ftrace_event_field *field; + unsigned long flags; + hist_field_fn_t fn; + unsigned int size; +}; + +static u64 hist_field_counter(struct hist_field *field, void *event) +{ + return 1; +} + +static u64 hist_field_string(struct hist_field *hist_field, void *event) +{ + char *addr = (char *)(event + hist_field->field->offset); + + return (u64)(unsigned long)addr; +} + +#define DEFINE_HIST_FIELD_FN(type) \ +static u64 hist_field_##type(struct hist_field *hist_field, void *event)\ +{ \ + type *addr = (type *)(event + hist_field->field->offset); \ + \ + return (u64)*addr; \ +} + +DEFINE_HIST_FIELD_FN(s64); +DEFINE_HIST_FIELD_FN(u64); +DEFINE_HIST_FIELD_FN(s32); +DEFINE_HIST_FIELD_FN(u32); +DEFINE_HIST_FIELD_FN(s16); +DEFINE_HIST_FIELD_FN(u16); +DEFINE_HIST_FIELD_FN(s8); +DEFINE_HIST_FIELD_FN(u8); + +#define for_each_hist_field(i, hist_data) \ + for ((i) = 0; (i) < (hist_data)->n_fields; (i)++) + +#define for_each_hist_val_field(i, hist_data) \ + for ((i) = 0; (i) < (hist_data)->n_vals; (i)++) + +#define for_each_hist_key_field(i, hist_data) \ + for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++) + +#define HITCOUNT_IDX 0 +#define HIST_KEY_MAX 1 +#define HIST_KEY_SIZE_MAX MAX_FILTER_STR_VAL + +enum hist_field_flags { + HIST_FIELD_FL_HITCOUNT = 1, + HIST_FIELD_FL_KEY = 2, + HIST_FIELD_FL_STRING = 4, +}; + +struct hist_trigger_attrs { + char *keys_str; + unsigned int map_bits; +}; + +struct hist_trigger_data { + struct hist_field *fields[TRACING_MAP_FIELDS_MAX]; + unsigned int n_vals; + unsigned int n_keys; + unsigned int n_fields; + unsigned int key_size; + struct tracing_map_sort_key sort_keys[TRACING_MAP_SORT_KEYS_MAX]; + unsigned int n_sort_keys; + struct trace_event_file *event_file; + struct hist_trigger_attrs *attrs; + struct tracing_map *map; +}; + +static hist_field_fn_t select_value_fn(int field_size, int field_is_signed) +{ + hist_field_fn_t fn = NULL; + + switch (field_size) { + case 8: + if (field_is_signed) + fn = hist_field_s64; + else + fn = hist_field_u64; + break; + case 4: + if (field_is_signed) + fn = hist_field_s32; + else + fn = hist_field_u32; + break; + case 2: + if (field_is_signed) + fn = hist_field_s16; + else + fn = hist_field_u16; + break; + case 1: + if (field_is_signed) + fn = hist_field_s8; + else + fn = hist_field_u8; + break; + } + + return fn; +} + +static int parse_map_size(char *str) +{ + unsigned long size, map_bits; + int ret; + + strsep(&str, "="); + if (!str) { + ret = -EINVAL; + goto out; + } + + ret = kstrtoul(str, 0, &size); + if (ret) + goto out; + + map_bits = ilog2(roundup_pow_of_two(size)); + if (map_bits < TRACING_MAP_BITS_MIN || + map_bits > TRACING_MAP_BITS_MAX) + ret = -EINVAL; + else + ret = map_bits; + out: + return ret; +} + +static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs) +{ + if (!attrs) + return; + + kfree(attrs->keys_str); + kfree(attrs); +} + +static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) +{ + struct hist_trigger_attrs *attrs; + int ret = 0; + + attrs = kzalloc(sizeof(*attrs), GFP_KERNEL); + if (!attrs) + return ERR_PTR(-ENOMEM); + + while (trigger_str) { + char *str = strsep(&trigger_str, ":"); + + if ((strncmp(str, "key=", strlen("key=")) == 0) || + (strncmp(str, "keys=", strlen("keys=")) == 0)) + attrs->keys_str = kstrdup(str, GFP_KERNEL); + else if (strncmp(str, "size=", strlen("size=")) == 0) { + int map_bits = parse_map_size(str); + + if (map_bits < 0) { + ret = map_bits; + goto free; + } + attrs->map_bits = map_bits; + } else { + ret = -EINVAL; + goto free; + } + } + + if (!attrs->keys_str) { + ret = -EINVAL; + goto free; + } + + return attrs; + free: + destroy_hist_trigger_attrs(attrs); + + return ERR_PTR(ret); +} + +static void destroy_hist_field(struct hist_field *hist_field) +{ + kfree(hist_field); +} + +static struct hist_field *create_hist_field(struct ftrace_event_field *field, + unsigned long flags) +{ + struct hist_field *hist_field; + + if (field && is_function_field(field)) + return NULL; + + hist_field = kzalloc(sizeof(struct hist_field), GFP_KERNEL); + if (!hist_field) + return NULL; + + if (flags & HIST_FIELD_FL_HITCOUNT) { + hist_field->fn = hist_field_counter; + goto out; + } + + if (is_string_field(field)) { + flags |= HIST_FIELD_FL_STRING; + hist_field->fn = hist_field_string; + } else { + hist_field->fn = select_value_fn(field->size, + field->is_signed); + if (!hist_field->fn) { + destroy_hist_field(hist_field); + return NULL; + } + } + out: + hist_field->field = field; + hist_field->flags = flags; + + return hist_field; +} + +static void destroy_hist_fields(struct hist_trigger_data *hist_data) +{ + unsigned int i; + + for (i = 0; i < TRACING_MAP_FIELDS_MAX; i++) { + if (hist_data->fields[i]) { + destroy_hist_field(hist_data->fields[i]); + hist_data->fields[i] = NULL; + } + } +} + +static int create_hitcount_val(struct hist_trigger_data *hist_data) +{ + hist_data->fields[HITCOUNT_IDX] = + create_hist_field(NULL, HIST_FIELD_FL_HITCOUNT); + if (!hist_data->fields[HITCOUNT_IDX]) + return -ENOMEM; + + hist_data->n_vals++; + + if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX)) + return -EINVAL; + + return 0; +} + +static int create_val_fields(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + int ret; + + ret = create_hitcount_val(hist_data); + + return ret; +} + +static int create_key_field(struct hist_trigger_data *hist_data, + unsigned int key_idx, + struct trace_event_file *file, + char *field_str) +{ + struct ftrace_event_field *field = NULL; + unsigned long flags = 0; + unsigned int key_size; + int ret = 0; + + if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX)) + return -EINVAL; + + flags |= HIST_FIELD_FL_KEY; + + field = trace_find_event_field(file->event_call, field_str); + if (!field) { + ret = -EINVAL; + goto out; + } + + key_size = field->size; + + hist_data->fields[key_idx] = create_hist_field(field, flags); + if (!hist_data->fields[key_idx]) { + ret = -ENOMEM; + goto out; + } + + key_size = ALIGN(key_size, sizeof(u64)); + hist_data->fields[key_idx]->size = key_size; + hist_data->key_size = key_size; + if (hist_data->key_size > HIST_KEY_SIZE_MAX) { + ret = -EINVAL; + goto out; + } + + hist_data->n_keys++; + + if (WARN_ON(hist_data->n_keys > TRACING_MAP_KEYS_MAX)) + return -EINVAL; + + ret = key_size; + out: + return ret; +} + +static int create_key_fields(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + unsigned int i, n_vals = hist_data->n_vals; + char *fields_str, *field_str; + int ret = -EINVAL; + + fields_str = hist_data->attrs->keys_str; + if (!fields_str) + goto out; + + strsep(&fields_str, "="); + if (!fields_str) + goto out; + + for (i = n_vals; i < n_vals + HIST_KEY_MAX; i++) { + field_str = strsep(&fields_str, ","); + if (!field_str) + break; + ret = create_key_field(hist_data, i, file, field_str); + if (ret < 0) + goto out; + } + if (fields_str) { + ret = -EINVAL; + goto out; + } + ret = 0; + out: + return ret; +} + +static int create_hist_fields(struct hist_trigger_data *hist_data, + struct trace_event_file *file) +{ + int ret; + + ret = create_val_fields(hist_data, file); + if (ret) + goto out; + + ret = create_key_fields(hist_data, file); + if (ret) + goto out; + + hist_data->n_fields = hist_data->n_vals + hist_data->n_keys; + out: + return ret; +} + +static int create_sort_keys(struct hist_trigger_data *hist_data) +{ + int ret = 0; + + hist_data->n_sort_keys = 1; /* sort_keys[0] is always hitcount */ + + return ret; +} + +static void destroy_hist_data(struct hist_trigger_data *hist_data) +{ + destroy_hist_trigger_attrs(hist_data->attrs); + destroy_hist_fields(hist_data); + tracing_map_destroy(hist_data->map); + kfree(hist_data); +} + +static int create_tracing_map_fields(struct hist_trigger_data *hist_data) +{ + struct tracing_map *map = hist_data->map; + struct ftrace_event_field *field; + struct hist_field *hist_field; + unsigned int i, idx; + + for_each_hist_field(i, hist_data) { + hist_field = hist_data->fields[i]; + if (hist_field->flags & HIST_FIELD_FL_KEY) { + tracing_map_cmp_fn_t cmp_fn; + + field = hist_field->field; + + if (is_string_field(field)) + cmp_fn = tracing_map_cmp_string; + else + cmp_fn = tracing_map_cmp_num(field->size, + field->is_signed); + idx = tracing_map_add_key_field(map, 0, cmp_fn); + } else + idx = tracing_map_add_sum_field(map); + + if (idx < 0) + return idx; + } + + return 0; +} + +static struct hist_trigger_data * +create_hist_data(unsigned int map_bits, + struct hist_trigger_attrs *attrs, + struct trace_event_file *file) +{ + struct hist_trigger_data *hist_data; + int ret = 0; + + hist_data = kzalloc(sizeof(*hist_data), GFP_KERNEL); + if (!hist_data) + return ERR_PTR(-ENOMEM); + + hist_data->attrs = attrs; + + ret = create_hist_fields(hist_data, file); + if (ret) + goto free; + + ret = create_sort_keys(hist_data); + if (ret) + goto free; + + hist_data->map = tracing_map_create(map_bits, hist_data->key_size, + NULL, hist_data); + if (IS_ERR(hist_data->map)) { + ret = PTR_ERR(hist_data->map); + hist_data->map = NULL; + goto free; + } + + ret = create_tracing_map_fields(hist_data); + if (ret) + goto free; + + ret = tracing_map_init(hist_data->map); + if (ret) + goto free; + + hist_data->event_file = file; + out: + return hist_data; + free: + hist_data->attrs = NULL; + + destroy_hist_data(hist_data); + + hist_data = ERR_PTR(ret); + + goto out; +} + +static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, + struct tracing_map_elt *elt, + void *rec) +{ + struct hist_field *hist_field; + unsigned int i; + u64 hist_val; + + for_each_hist_val_field(i, hist_data) { + hist_field = hist_data->fields[i]; + hist_val = hist_field->fn(hist_field, rec); + tracing_map_update_sum(elt, i, hist_val); + } +} + +static void event_hist_trigger(struct event_trigger_data *data, void *rec) +{ + struct hist_trigger_data *hist_data = data->private_data; + struct hist_field *key_field; + struct tracing_map_elt *elt; + u64 field_contents; + void *key = NULL; + unsigned int i; + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + + field_contents = key_field->fn(key_field, rec); + if (key_field->flags & HIST_FIELD_FL_STRING) + key = (void *)(unsigned long)field_contents; + else + key = (void *)&field_contents; + } + + elt = tracing_map_insert(hist_data->map, key); + if (elt) + hist_trigger_elt_update(hist_data, elt, rec); +} + +static void +hist_trigger_entry_print(struct seq_file *m, + struct hist_trigger_data *hist_data, void *key, + struct tracing_map_elt *elt) +{ + struct hist_field *key_field; + unsigned int i; + u64 uval; + + seq_puts(m, "{ "); + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + + if (i > hist_data->n_vals) + seq_puts(m, ", "); + + if (key_field->flags & HIST_FIELD_FL_STRING) { + seq_printf(m, "%s: %-50s", key_field->field->name, + (char *)key); + } else { + uval = *(u64 *)key; + seq_printf(m, "%s: %10llu", + key_field->field->name, uval); + } + } + + seq_puts(m, " }"); + + seq_printf(m, " hitcount: %10llu", + tracing_map_read_sum(elt, HITCOUNT_IDX)); + + seq_puts(m, "\n"); +} + +static int print_entries(struct seq_file *m, + struct hist_trigger_data *hist_data) +{ + struct tracing_map_sort_entry **sort_entries = NULL; + struct tracing_map *map = hist_data->map; + unsigned int i, n_entries; + + n_entries = tracing_map_sort_entries(map, hist_data->sort_keys, + hist_data->n_sort_keys, + &sort_entries); + if (n_entries < 0) + return n_entries; + + for (i = 0; i < n_entries; i++) + hist_trigger_entry_print(m, hist_data, + sort_entries[i]->key, + sort_entries[i]->elt); + + tracing_map_destroy_sort_entries(sort_entries, n_entries); + + return n_entries; +} + +static int hist_show(struct seq_file *m, void *v) +{ + struct event_trigger_data *test, *data = NULL; + struct trace_event_file *event_file; + struct hist_trigger_data *hist_data; + int n_entries, ret = 0; + + mutex_lock(&event_mutex); + + event_file = event_file_data(m->private); + if (unlikely(!event_file)) { + ret = -ENODEV; + goto out_unlock; + } + + list_for_each_entry_rcu(test, &event_file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + data = test; + break; + } + } + if (!data) + goto out_unlock; + + seq_puts(m, "# event histogram\n#\n# trigger info: "); + data->ops->print(m, data->ops, data); + seq_puts(m, "\n"); + + hist_data = data->private_data; + n_entries = print_entries(m, hist_data); + if (n_entries < 0) { + ret = n_entries; + n_entries = 0; + } + + seq_printf(m, "\nTotals:\n Hits: %llu\n Entries: %u\n Dropped: %llu\n", + (u64)atomic64_read(&hist_data->map->hits), + n_entries, (u64)atomic64_read(&hist_data->map->drops)); + out_unlock: + mutex_unlock(&event_mutex); + + return ret; +} + +static int event_hist_open(struct inode *inode, struct file *file) +{ + return single_open(file, hist_show, file); +} + +const struct file_operations event_hist_fops = { + .open = event_hist_open, + .read = seq_read, + .llseek = seq_lseek, + .release = single_release, +}; + +static void hist_field_print(struct seq_file *m, struct hist_field *hist_field) +{ + seq_printf(m, "%s", hist_field->field->name); +} + +static int event_hist_trigger_print(struct seq_file *m, + struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + struct hist_trigger_data *hist_data = data->private_data; + struct hist_field *key_field; + unsigned int i; + + seq_puts(m, "hist:keys="); + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + + if (i > hist_data->n_vals) + seq_puts(m, ","); + + hist_field_print(m, key_field); + } + + seq_puts(m, ":vals="); + seq_puts(m, "hitcount"); + + seq_puts(m, ":sort="); + seq_puts(m, "hitcount"); + + seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits)); + + if (data->filter_str) + seq_printf(m, " if %s", data->filter_str); + + seq_puts(m, " [active]"); + + seq_putc(m, '\n'); + + return 0; +} + +static void event_hist_trigger_free(struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + struct hist_trigger_data *hist_data = data->private_data; + + if (WARN_ON_ONCE(data->ref <= 0)) + return; + + data->ref--; + if (!data->ref) { + trigger_data_free(data); + destroy_hist_data(hist_data); + } +} + +static struct event_trigger_ops event_hist_trigger_ops = { + .func = event_hist_trigger, + .print = event_hist_trigger_print, + .init = event_trigger_init, + .free = event_hist_trigger_free, +}; + +static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd, + char *param) +{ + return &event_hist_trigger_ops; +} + +static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, + struct event_trigger_data *data, + struct trace_event_file *file) +{ + struct event_trigger_data *test; + int ret = 0; + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + ret = -EEXIST; + goto out; + } + } + + if (data->ops->init) { + ret = data->ops->init(data->ops, data); + if (ret < 0) + goto out; + } + + list_add_rcu(&data->list, &file->triggers); + ret++; + + update_cond_flag(file); + if (trace_event_trigger_enable_disable(file, 1) < 0) { + list_del_rcu(&data->list); + update_cond_flag(file); + ret--; + } + out: + return ret; +} + +static int event_hist_trigger_func(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, char *cmd, char *param) +{ + unsigned int hist_trigger_bits = TRACING_MAP_BITS_DEFAULT; + struct event_trigger_data *trigger_data; + struct hist_trigger_attrs *attrs; + struct event_trigger_ops *trigger_ops; + struct hist_trigger_data *hist_data; + char *trigger; + int ret = 0; + + if (!param) + return -EINVAL; + + /* separate the trigger from the filter (k:v [if filter]) */ + trigger = strsep(¶m, " \t"); + if (!trigger) + return -EINVAL; + + attrs = parse_hist_trigger_attrs(trigger); + if (IS_ERR(attrs)) + return PTR_ERR(attrs); + + if (attrs->map_bits) + hist_trigger_bits = attrs->map_bits; + + hist_data = create_hist_data(hist_trigger_bits, attrs, file); + if (IS_ERR(hist_data)) { + destroy_hist_trigger_attrs(attrs); + return PTR_ERR(hist_data); + } + + trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); + + ret = -ENOMEM; + trigger_data = kzalloc(sizeof(*trigger_data), GFP_KERNEL); + if (!trigger_data) + goto out_free; + + trigger_data->count = -1; + trigger_data->ops = trigger_ops; + trigger_data->cmd_ops = cmd_ops; + + INIT_LIST_HEAD(&trigger_data->list); + RCU_INIT_POINTER(trigger_data->filter, NULL); + + trigger_data->private_data = hist_data; + + if (glob[0] == '!') { + cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); + ret = 0; + goto out_free; + } + + if (!param) /* if param is non-empty, it's supposed to be a filter */ + goto out_reg; + + if (!cmd_ops->set_filter) + goto out_reg; + + ret = cmd_ops->set_filter(param, trigger_data, file); + if (ret < 0) + goto out_free; + out_reg: + ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); + /* + * The above returns on success the # of triggers registered, + * but if it didn't register any it returns zero. Consider no + * triggers registered a failure too. + */ + if (!ret) { + ret = -ENOENT; + goto out_free; + } else if (ret < 0) + goto out_free; + /* Just return zero, not the number of registered triggers */ + ret = 0; + out: + return ret; + out_free: + if (cmd_ops->set_filter) + cmd_ops->set_filter(NULL, trigger_data, NULL); + + kfree(trigger_data); + + destroy_hist_data(hist_data); + goto out; +} + +static struct event_command trigger_hist_cmd = { + .name = "hist", + .trigger_type = ETT_EVENT_HIST, + .flags = EVENT_CMD_FL_NEEDS_REC, + .func = event_hist_trigger_func, + .reg = hist_register_trigger, + .unreg = unregister_trigger, + .get_trigger_ops = event_hist_get_trigger_ops, + .set_filter = set_trigger_filter, +}; + +__init int register_trigger_hist_cmd(void) +{ + int ret; + + ret = register_event_command(&trigger_hist_cmd); + WARN_ON(ret < 0); + + return ret; +} diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index d67992f3bb0e..d29092afe005 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -1447,6 +1447,7 @@ __init int register_trigger_cmds(void) register_trigger_snapshot_cmd(); register_trigger_stacktrace_cmd(); register_trigger_enable_disable_cmds(); + register_trigger_hist_cmd(); return 0; } From f2606835d70d2a2e6a134f01821da8149e124796 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:43 -0600 Subject: [PATCH 09/45] tracing: Add hist trigger support for multiple values ('vals=' param) Allow users to specify trace event fields to use in aggregated sums via a new 'vals=' keyword. Before this addition, the only aggregated sum supported was the implied value 'hitcount'. With this addition, 'hitcount' is also supported as an explicit value field, as is any numeric trace event field. This expands the hist trigger syntax from this: # echo hist:keys=xxx [ if filter] > event/trigger to this: # echo hist:keys=xxx:vals=yyy [ if filter] > event/trigger Link: http://lkml.kernel.org/r/2a5d1adb5ba6c65d7bb2148e379f2fed47f29a68.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 12 +++-- kernel/trace/trace_events_hist.c | 79 +++++++++++++++++++++++++++++++- 2 files changed, 85 insertions(+), 6 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 6cf8fd03b028..bb62f54c5480 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3834,14 +3834,16 @@ static const char readme_msg[] = #ifdef CONFIG_HIST_TRIGGERS " hist trigger\t- If set, event hits are aggregated into a hash table\n" "\t Format: hist:keys=\n" + "\t [:values=]\n" "\t [:size=#entries]\n" "\t [if ]\n\n" "\t When a matching event is hit, an entry is added to a hash\n" - "\t table using the key named, and the value of a sum called\n" - "\t 'hitcount' is incremented. Keys correspond to fields in the\n" - "\t event's format description. Keys can be any field. The\n" - "\t 'size' parameter can be used to specify more or fewer than\n" - "\t the default 2048 entries for the hashtable size.\n\n" + "\t table using the key(s) and value(s) named, and the value of a\n" + "\t sum called 'hitcount' is incremented. Keys and values\n" + "\t correspond to fields in the event's format description. Keys\n" + "\t can be any field. Values must correspond to numeric fields.\n" + "\t The 'size' parameter can be used to specify more or fewer\n" + "\t than the default 2048 entries for the hashtable size.\n\n" "\t Reading the 'hist' file for the event will dump the hash\n" "\t table in its entirety to stdout." #endif diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 23b45e462117..1b33590b9c8f 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -84,6 +84,7 @@ enum hist_field_flags { struct hist_trigger_attrs { char *keys_str; + char *vals_str; unsigned int map_bits; }; @@ -165,6 +166,7 @@ static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs) return; kfree(attrs->keys_str); + kfree(attrs->vals_str); kfree(attrs); } @@ -183,6 +185,10 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) if ((strncmp(str, "key=", strlen("key=")) == 0) || (strncmp(str, "keys=", strlen("keys=")) == 0)) attrs->keys_str = kstrdup(str, GFP_KERNEL); + else if ((strncmp(str, "val=", strlen("val=")) == 0) || + (strncmp(str, "vals=", strlen("vals=")) == 0) || + (strncmp(str, "values=", strlen("values=")) == 0)) + attrs->vals_str = kstrdup(str, GFP_KERNEL); else if (strncmp(str, "size=", strlen("size=")) == 0) { int map_bits = parse_map_size(str); @@ -276,13 +282,70 @@ static int create_hitcount_val(struct hist_trigger_data *hist_data) return 0; } +static int create_val_field(struct hist_trigger_data *hist_data, + unsigned int val_idx, + struct trace_event_file *file, + char *field_str) +{ + struct ftrace_event_field *field = NULL; + unsigned long flags = 0; + int ret = 0; + + if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX)) + return -EINVAL; + field = trace_find_event_field(file->event_call, field_str); + if (!field) { + ret = -EINVAL; + goto out; + } + + hist_data->fields[val_idx] = create_hist_field(field, flags); + if (!hist_data->fields[val_idx]) { + ret = -ENOMEM; + goto out; + } + + ++hist_data->n_vals; + + if (WARN_ON(hist_data->n_vals > TRACING_MAP_VALS_MAX)) + ret = -EINVAL; + out: + return ret; +} + static int create_val_fields(struct hist_trigger_data *hist_data, struct trace_event_file *file) { + char *fields_str, *field_str; + unsigned int i, j; int ret; ret = create_hitcount_val(hist_data); + if (ret) + goto out; + fields_str = hist_data->attrs->vals_str; + if (!fields_str) + goto out; + + strsep(&fields_str, "="); + if (!fields_str) + goto out; + + for (i = 0, j = 1; i < TRACING_MAP_VALS_MAX && + j < TRACING_MAP_VALS_MAX; i++) { + field_str = strsep(&fields_str, ","); + if (!field_str) + break; + if (strcmp(field_str, "hitcount") == 0) + continue; + ret = create_val_field(hist_data, j++, file, field_str); + if (ret) + goto out; + } + if (fields_str && (strcmp(fields_str, "hitcount") != 0)) + ret = -EINVAL; + out: return ret; } @@ -552,6 +615,12 @@ hist_trigger_entry_print(struct seq_file *m, seq_printf(m, " hitcount: %10llu", tracing_map_read_sum(elt, HITCOUNT_IDX)); + for (i = 1; i < hist_data->n_vals; i++) { + seq_printf(m, " %s: %10llu", + hist_data->fields[i]->field->name, + tracing_map_read_sum(elt, i)); + } + seq_puts(m, "\n"); } @@ -659,7 +728,15 @@ static int event_hist_trigger_print(struct seq_file *m, } seq_puts(m, ":vals="); - seq_puts(m, "hitcount"); + + for_each_hist_val_field(i, hist_data) { + if (i == HITCOUNT_IDX) + seq_puts(m, "hitcount"); + else { + seq_puts(m, ","); + hist_field_print(m, hist_data->fields[i]); + } + } seq_puts(m, ":sort="); seq_puts(m, "hitcount"); From 76a3b0c8ac344e1d0f436160cbb59b670b086947 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:44 -0600 Subject: [PATCH 10/45] tracing: Add hist trigger support for compound keys Allow users to specify multiple trace event fields to use in keys by allowing multiple fields in the 'keys=' keyword. With this addition, any unique combination of any of the fields named in the 'keys' keyword will result in a new entry being added to the hash table. Link: http://lkml.kernel.org/r/0cfa24e6ac3b0dcece7737d94aa1f322ae3afc4b.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 10 ++++---- kernel/trace/trace_events_hist.c | 41 +++++++++++++++++++++++--------- 2 files changed, 36 insertions(+), 15 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index bb62f54c5480..7a4c4dcf0bfe 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3833,7 +3833,7 @@ static const char readme_msg[] = "\t Filters can be ignored when removing a trigger.\n" #ifdef CONFIG_HIST_TRIGGERS " hist trigger\t- If set, event hits are aggregated into a hash table\n" - "\t Format: hist:keys=\n" + "\t Format: hist:keys=\n" "\t [:values=]\n" "\t [:size=#entries]\n" "\t [if ]\n\n" @@ -3841,9 +3841,11 @@ static const char readme_msg[] = "\t table using the key(s) and value(s) named, and the value of a\n" "\t sum called 'hitcount' is incremented. Keys and values\n" "\t correspond to fields in the event's format description. Keys\n" - "\t can be any field. Values must correspond to numeric fields.\n" - "\t The 'size' parameter can be used to specify more or fewer\n" - "\t than the default 2048 entries for the hashtable size.\n\n" + "\t can be any field. Compound keys consisting of up to two\n" + "\t fields can be specified by the 'keys' keyword. Values must\n" + "\t correspond to numeric fields. The 'size' parameter can be\n" + "\t used to specify more or fewer than the default 2048 entries\n" + "\t for the hashtable size.\n\n" "\t Reading the 'hist' file for the event will dump the hash\n" "\t table in its entirety to stdout." #endif diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 1b33590b9c8f..65fdfc6cb633 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -32,6 +32,7 @@ struct hist_field { unsigned long flags; hist_field_fn_t fn; unsigned int size; + unsigned int offset; }; static u64 hist_field_counter(struct hist_field *field, void *event) @@ -73,8 +74,7 @@ DEFINE_HIST_FIELD_FN(u8); for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++) #define HITCOUNT_IDX 0 -#define HIST_KEY_MAX 1 -#define HIST_KEY_SIZE_MAX MAX_FILTER_STR_VAL +#define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + sizeof(u64)) enum hist_field_flags { HIST_FIELD_FL_HITCOUNT = 1, @@ -351,6 +351,7 @@ static int create_val_fields(struct hist_trigger_data *hist_data, static int create_key_field(struct hist_trigger_data *hist_data, unsigned int key_idx, + unsigned int key_offset, struct trace_event_file *file, char *field_str) { @@ -380,7 +381,8 @@ static int create_key_field(struct hist_trigger_data *hist_data, key_size = ALIGN(key_size, sizeof(u64)); hist_data->fields[key_idx]->size = key_size; - hist_data->key_size = key_size; + hist_data->fields[key_idx]->offset = key_offset; + hist_data->key_size += key_size; if (hist_data->key_size > HIST_KEY_SIZE_MAX) { ret = -EINVAL; goto out; @@ -399,7 +401,7 @@ static int create_key_field(struct hist_trigger_data *hist_data, static int create_key_fields(struct hist_trigger_data *hist_data, struct trace_event_file *file) { - unsigned int i, n_vals = hist_data->n_vals; + unsigned int i, key_offset = 0, n_vals = hist_data->n_vals; char *fields_str, *field_str; int ret = -EINVAL; @@ -411,13 +413,15 @@ static int create_key_fields(struct hist_trigger_data *hist_data, if (!fields_str) goto out; - for (i = n_vals; i < n_vals + HIST_KEY_MAX; i++) { + for (i = n_vals; i < n_vals + TRACING_MAP_KEYS_MAX; i++) { field_str = strsep(&fields_str, ","); if (!field_str) break; - ret = create_key_field(hist_data, i, file, field_str); + ret = create_key_field(hist_data, i, key_offset, + file, field_str); if (ret < 0) goto out; + key_offset += ret; } if (fields_str) { ret = -EINVAL; @@ -482,7 +486,10 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data) else cmp_fn = tracing_map_cmp_num(field->size, field->is_signed); - idx = tracing_map_add_key_field(map, 0, cmp_fn); + idx = tracing_map_add_key_field(map, + hist_field->offset, + cmp_fn); + } else idx = tracing_map_add_sum_field(map); @@ -562,12 +569,16 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, static void event_hist_trigger(struct event_trigger_data *data, void *rec) { struct hist_trigger_data *hist_data = data->private_data; + char compound_key[HIST_KEY_SIZE_MAX]; struct hist_field *key_field; struct tracing_map_elt *elt; u64 field_contents; void *key = NULL; unsigned int i; + if (hist_data->n_keys > 1) + memset(compound_key, 0, hist_data->key_size); + for_each_hist_key_field(i, hist_data) { key_field = hist_data->fields[i]; @@ -576,8 +587,16 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec) key = (void *)(unsigned long)field_contents; else key = (void *)&field_contents; + + if (hist_data->n_keys > 1) { + memcpy(compound_key + key_field->offset, key, + key_field->size); + } } + if (hist_data->n_keys > 1) + key = compound_key; + elt = tracing_map_insert(hist_data->map, key); if (elt) hist_trigger_elt_update(hist_data, elt, rec); @@ -602,11 +621,11 @@ hist_trigger_entry_print(struct seq_file *m, if (key_field->flags & HIST_FIELD_FL_STRING) { seq_printf(m, "%s: %-50s", key_field->field->name, - (char *)key); + (char *)(key + key_field->offset)); } else { - uval = *(u64 *)key; - seq_printf(m, "%s: %10llu", - key_field->field->name, uval); + uval = *(u64 *)(key + key_field->offset); + seq_printf(m, "%s: %10llu", key_field->field->name, + uval); } } From e62347d2453474fa514fbbbc4636313d34d3c850 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:45 -0600 Subject: [PATCH 11/45] tracing: Add hist trigger support for user-defined sorting ('sort=' param) Allow users to specify keys and/or values to sort on. With this addition, keys and values specified using the 'keys=' and 'vals=' keywords can be used to sort the hist trigger output via a new 'sort=' keyword. If multiple sort keys are specified, the output will be sorted using the second key as a secondary sort key, etc. The default sort order is ascending; if the user wants a different sort order, '.descending' can be appended to the specific sort key. Before this addition, output was always sorted by 'hitcount' in ascending order. This expands the hist trigger syntax from this: # echo hist:keys=xxx:vals=yyy \ [ if filter] > event/trigger to this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending \ [ if filter] > event/trigger Link: http://lkml.kernel.org/r/b30a41db66ba486979c4f987aff5fab500ea53b3.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 6 +- kernel/trace/trace_events_hist.c | 112 ++++++++++++++++++++++++++++++- 2 files changed, 114 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7a4c4dcf0bfe..d16fa8e1cdbf 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3835,6 +3835,7 @@ static const char readme_msg[] = " hist trigger\t- If set, event hits are aggregated into a hash table\n" "\t Format: hist:keys=\n" "\t [:values=]\n" + "\t [:sort=]\n" "\t [:size=#entries]\n" "\t [if ]\n\n" "\t When a matching event is hit, an entry is added to a hash\n" @@ -3843,7 +3844,10 @@ static const char readme_msg[] = "\t correspond to fields in the event's format description. Keys\n" "\t can be any field. Compound keys consisting of up to two\n" "\t fields can be specified by the 'keys' keyword. Values must\n" - "\t correspond to numeric fields. The 'size' parameter can be\n" + "\t correspond to numeric fields. Sort keys consisting of up to\n" + "\t two fields can be specified using the 'sort' keyword. The\n" + "\t sort direction can be modified by appending '.descending' or\n" + "\t '.ascending' to a sort field. The 'size' parameter can be\n" "\t used to specify more or fewer than the default 2048 entries\n" "\t for the hashtable size.\n\n" "\t Reading the 'hist' file for the event will dump the hash\n" diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 65fdfc6cb633..03ba4530c08c 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -85,6 +85,7 @@ enum hist_field_flags { struct hist_trigger_attrs { char *keys_str; char *vals_str; + char *sort_key_str; unsigned int map_bits; }; @@ -165,6 +166,7 @@ static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs) if (!attrs) return; + kfree(attrs->sort_key_str); kfree(attrs->keys_str); kfree(attrs->vals_str); kfree(attrs); @@ -189,6 +191,8 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) (strncmp(str, "vals=", strlen("vals=")) == 0) || (strncmp(str, "values=", strlen("values=")) == 0)) attrs->vals_str = kstrdup(str, GFP_KERNEL); + else if (strncmp(str, "sort=", strlen("sort=")) == 0) + attrs->sort_key_str = kstrdup(str, GFP_KERNEL); else if (strncmp(str, "size=", strlen("size=")) == 0) { int map_bits = parse_map_size(str); @@ -450,12 +454,92 @@ static int create_hist_fields(struct hist_trigger_data *hist_data, return ret; } +static int is_descending(const char *str) +{ + if (!str) + return 0; + + if (strcmp(str, "descending") == 0) + return 1; + + if (strcmp(str, "ascending") == 0) + return 0; + + return -EINVAL; +} + static int create_sort_keys(struct hist_trigger_data *hist_data) { - int ret = 0; + char *fields_str = hist_data->attrs->sort_key_str; + struct ftrace_event_field *field = NULL; + struct tracing_map_sort_key *sort_key; + int descending, ret = 0; + unsigned int i, j; - hist_data->n_sort_keys = 1; /* sort_keys[0] is always hitcount */ + hist_data->n_sort_keys = 1; /* we always have at least one, hitcount */ + if (!fields_str) + goto out; + + strsep(&fields_str, "="); + if (!fields_str) { + ret = -EINVAL; + goto out; + } + + for (i = 0; i < TRACING_MAP_SORT_KEYS_MAX; i++) { + char *field_str, *field_name; + + sort_key = &hist_data->sort_keys[i]; + + field_str = strsep(&fields_str, ","); + if (!field_str) { + if (i == 0) + ret = -EINVAL; + break; + } + + if ((i == TRACING_MAP_SORT_KEYS_MAX - 1) && fields_str) { + ret = -EINVAL; + break; + } + + field_name = strsep(&field_str, "."); + if (!field_name) { + ret = -EINVAL; + break; + } + + if (strcmp(field_name, "hitcount") == 0) { + descending = is_descending(field_str); + if (descending < 0) { + ret = descending; + break; + } + sort_key->descending = descending; + continue; + } + + for (j = 1; j < hist_data->n_fields; j++) { + field = hist_data->fields[j]->field; + if (field && (strcmp(field_name, field->name) == 0)) { + sort_key->field_idx = j; + descending = is_descending(field_str); + if (descending < 0) { + ret = descending; + goto out; + } + sort_key->descending = descending; + break; + } + } + if (j == hist_data->n_fields) { + ret = -EINVAL; + break; + } + } + hist_data->n_sort_keys = i; + out: return ret; } @@ -758,7 +842,29 @@ static int event_hist_trigger_print(struct seq_file *m, } seq_puts(m, ":sort="); - seq_puts(m, "hitcount"); + + for (i = 0; i < hist_data->n_sort_keys; i++) { + struct tracing_map_sort_key *sort_key; + + sort_key = &hist_data->sort_keys[i]; + + if (i > 0) + seq_puts(m, ","); + + if (sort_key->field_idx == HITCOUNT_IDX) + seq_puts(m, "hitcount"); + else { + unsigned int idx = sort_key->field_idx; + + if (WARN_ON(idx >= TRACING_MAP_FIELDS_MAX)) + return -EINVAL; + + hist_field_print(m, hist_data->fields[idx]); + } + + if (sort_key->descending) + seq_puts(m, ".descending"); + } seq_printf(m, ":size=%u", (1 << hist_data->map->map_bits)); From 83e99914c9e2677d8a80f2a23eca0d215d5bfb0f Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:46 -0600 Subject: [PATCH 12/45] tracing: Add hist trigger support for pausing and continuing a trace Allow users to append 'pause' or 'continue' to an existing trigger in order to have it paused or to have a paused trace continue. This expands the hist trigger syntax from this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending \ [ if filter] >> event/trigger to this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause or cont \ [ if filter] >> event/trigger Link: http://lkml.kernel.org/r/b672a92c14702cb924cdf6fc27ea1809bed04907.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 7 ++++++- kernel/trace/trace_events_hist.c | 31 ++++++++++++++++++++++++++++--- 2 files changed, 34 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index d16fa8e1cdbf..7d5c63dd410a 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3837,6 +3837,7 @@ static const char readme_msg[] = "\t [:values=]\n" "\t [:sort=]\n" "\t [:size=#entries]\n" + "\t [:pause][:continue]\n" "\t [if ]\n\n" "\t When a matching event is hit, an entry is added to a hash\n" "\t table using the key(s) and value(s) named, and the value of a\n" @@ -3851,7 +3852,11 @@ static const char readme_msg[] = "\t used to specify more or fewer than the default 2048 entries\n" "\t for the hashtable size.\n\n" "\t Reading the 'hist' file for the event will dump the hash\n" - "\t table in its entirety to stdout." + "\t table in its entirety to stdout.\n\n" + "\t The 'pause' parameter can be used to pause an existing hist\n" + "\t trigger or to start a hist trigger but not log any events\n" + "\t until told to do so. 'continue' can be used to start or\n" + "\t restart a paused hist trigger.\n\n" #endif ; diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 03ba4530c08c..e3fa9c89f125 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -86,6 +86,8 @@ struct hist_trigger_attrs { char *keys_str; char *vals_str; char *sort_key_str; + bool pause; + bool cont; unsigned int map_bits; }; @@ -193,6 +195,11 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) attrs->vals_str = kstrdup(str, GFP_KERNEL); else if (strncmp(str, "sort=", strlen("sort=")) == 0) attrs->sort_key_str = kstrdup(str, GFP_KERNEL); + else if (strcmp(str, "pause") == 0) + attrs->pause = true; + else if ((strcmp(str, "cont") == 0) || + (strcmp(str, "continue") == 0)) + attrs->cont = true; else if (strncmp(str, "size=", strlen("size=")) == 0) { int map_bits = parse_map_size(str); @@ -871,7 +878,10 @@ static int event_hist_trigger_print(struct seq_file *m, if (data->filter_str) seq_printf(m, " if %s", data->filter_str); - seq_puts(m, " [active]"); + if (data->paused) + seq_puts(m, " [paused]"); + else + seq_puts(m, " [active]"); seq_putc(m, '\n'); @@ -910,16 +920,30 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file) { + struct hist_trigger_data *hist_data = data->private_data; struct event_trigger_data *test; int ret = 0; list_for_each_entry_rcu(test, &file->triggers, list) { if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { - ret = -EEXIST; + if (hist_data->attrs->pause) + test->paused = true; + else if (hist_data->attrs->cont) + test->paused = false; + else + ret = -EEXIST; goto out; } } + if (hist_data->attrs->cont) { + ret = -ENOENT; + goto out; + } + + if (hist_data->attrs->pause) + data->paused = true; + if (data->ops->init) { ret = data->ops->init(data->ops, data); if (ret < 0) @@ -1011,7 +1035,8 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, * triggers registered a failure too. */ if (!ret) { - ret = -ENOENT; + if (!(attrs->pause || attrs->cont)) + ret = -ENOENT; goto out_free; } else if (ret < 0) goto out_free; From e86ae9baacfa9efe957df4fc037f079772636d76 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:47 -0600 Subject: [PATCH 13/45] tracing: Add hist trigger support for clearing a trace Allow users to append 'clear' to an existing trigger in order to have the hash table cleared. This expands the hist trigger syntax from this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause/cont \ [ if filter] >> event/trigger to this: # echo hist:keys=xxx:vals=yyy:sort=zzz.descending:pause/cont/clear \ [ if filter] >> event/trigger Link: http://lkml.kernel.org/r/ae15dd0d9b2f7af07a37c1ff682063e2dbcdf160.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 5 ++++- kernel/trace/trace_events_hist.c | 24 ++++++++++++++++++++++-- 2 files changed, 26 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 7d5c63dd410a..4097cd3763f7 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3837,7 +3837,7 @@ static const char readme_msg[] = "\t [:values=]\n" "\t [:sort=]\n" "\t [:size=#entries]\n" - "\t [:pause][:continue]\n" + "\t [:pause][:continue][:clear]\n" "\t [if ]\n\n" "\t When a matching event is hit, an entry is added to a hash\n" "\t table using the key(s) and value(s) named, and the value of a\n" @@ -3857,6 +3857,9 @@ static const char readme_msg[] = "\t trigger or to start a hist trigger but not log any events\n" "\t until told to do so. 'continue' can be used to start or\n" "\t restart a paused hist trigger.\n\n" + "\t The 'clear' parameter will clear the contents of a running\n" + "\t hist trigger and leave its current paused/active state\n" + "\t unchanged.\n\n" #endif ; diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index e3fa9c89f125..83cb25e067ad 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -88,6 +88,7 @@ struct hist_trigger_attrs { char *sort_key_str; bool pause; bool cont; + bool clear; unsigned int map_bits; }; @@ -200,6 +201,8 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) else if ((strcmp(str, "cont") == 0) || (strcmp(str, "continue") == 0)) attrs->cont = true; + else if (strcmp(str, "clear") == 0) + attrs->clear = true; else if (strncmp(str, "size=", strlen("size=")) == 0) { int map_bits = parse_map_size(str); @@ -916,6 +919,21 @@ static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd, return &event_hist_trigger_ops; } +static void hist_clear(struct event_trigger_data *data) +{ + struct hist_trigger_data *hist_data = data->private_data; + bool paused; + + paused = data->paused; + data->paused = true; + + synchronize_sched(); + + tracing_map_clear(hist_data->map); + + data->paused = paused; +} + static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file) @@ -930,13 +948,15 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, test->paused = true; else if (hist_data->attrs->cont) test->paused = false; + else if (hist_data->attrs->clear) + hist_clear(test); else ret = -EEXIST; goto out; } } - if (hist_data->attrs->cont) { + if (hist_data->attrs->cont || hist_data->attrs->clear) { ret = -ENOENT; goto out; } @@ -1035,7 +1055,7 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, * triggers registered a failure too. */ if (!ret) { - if (!(attrs->pause || attrs->cont)) + if (!(attrs->pause || attrs->cont || attrs->clear)) ret = -ENOENT; goto out_free; } else if (ret < 0) From 0c4a6b4666e8eb86dead3f09b40bb8ca4f614e4f Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:48 -0600 Subject: [PATCH 14/45] tracing: Add hist trigger 'hex' modifier for displaying numeric fields Allow users to have numeric fields displayed as hex values in the output by appending '.hex' to field names: # echo hist:keys=aaa,bbb.hex:vals=ccc.hex ... \ [ if filter] > event/trigger Link: http://lkml.kernel.org/r/67bd431edda2af5798d7694818f7e8d71b6b3463.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 5 ++- kernel/trace/trace_events_hist.c | 62 ++++++++++++++++++++++++++++---- 2 files changed, 60 insertions(+), 7 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4097cd3763f7..2eb2eafbe7f5 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3852,7 +3852,10 @@ static const char readme_msg[] = "\t used to specify more or fewer than the default 2048 entries\n" "\t for the hashtable size.\n\n" "\t Reading the 'hist' file for the event will dump the hash\n" - "\t table in its entirety to stdout.\n\n" + "\t table in its entirety to stdout. The default format used to\n" + "\t display a given field can be modified by appending any of the\n" + "\t following modifiers to the field name, as applicable:\n\n" + "\t .hex display a number as a hex value\n\n" "\t The 'pause' parameter can be used to pause an existing hist\n" "\t trigger or to start a hist trigger but not log any events\n" "\t until told to do so. 'continue' can be used to start or\n" diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 83cb25e067ad..8e49eeef8867 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -80,6 +80,7 @@ enum hist_field_flags { HIST_FIELD_FL_HITCOUNT = 1, HIST_FIELD_FL_KEY = 2, HIST_FIELD_FL_STRING = 4, + HIST_FIELD_FL_HEX = 8, }; struct hist_trigger_attrs { @@ -303,11 +304,23 @@ static int create_val_field(struct hist_trigger_data *hist_data, { struct ftrace_event_field *field = NULL; unsigned long flags = 0; + char *field_name; int ret = 0; if (WARN_ON(val_idx >= TRACING_MAP_VALS_MAX)) return -EINVAL; - field = trace_find_event_field(file->event_call, field_str); + + field_name = strsep(&field_str, "."); + if (field_str) { + if (strcmp(field_str, "hex") == 0) + flags |= HIST_FIELD_FL_HEX; + else { + ret = -EINVAL; + goto out; + } + } + + field = trace_find_event_field(file->event_call, field_name); if (!field) { ret = -EINVAL; goto out; @@ -372,6 +385,7 @@ static int create_key_field(struct hist_trigger_data *hist_data, struct ftrace_event_field *field = NULL; unsigned long flags = 0; unsigned int key_size; + char *field_name; int ret = 0; if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX)) @@ -379,7 +393,17 @@ static int create_key_field(struct hist_trigger_data *hist_data, flags |= HIST_FIELD_FL_KEY; - field = trace_find_event_field(file->event_call, field_str); + field_name = strsep(&field_str, "."); + if (field_str) { + if (strcmp(field_str, "hex") == 0) + flags |= HIST_FIELD_FL_HEX; + else { + ret = -EINVAL; + goto out; + } + } + + field = trace_find_event_field(file->event_call, field_name); if (!field) { ret = -EINVAL; goto out; @@ -713,7 +737,11 @@ hist_trigger_entry_print(struct seq_file *m, if (i > hist_data->n_vals) seq_puts(m, ", "); - if (key_field->flags & HIST_FIELD_FL_STRING) { + if (key_field->flags & HIST_FIELD_FL_HEX) { + uval = *(u64 *)(key + key_field->offset); + seq_printf(m, "%s: %llx", + key_field->field->name, uval); + } else if (key_field->flags & HIST_FIELD_FL_STRING) { seq_printf(m, "%s: %-50s", key_field->field->name, (char *)(key + key_field->offset)); } else { @@ -729,9 +757,15 @@ hist_trigger_entry_print(struct seq_file *m, tracing_map_read_sum(elt, HITCOUNT_IDX)); for (i = 1; i < hist_data->n_vals; i++) { - seq_printf(m, " %s: %10llu", - hist_data->fields[i]->field->name, - tracing_map_read_sum(elt, i)); + if (hist_data->fields[i]->flags & HIST_FIELD_FL_HEX) { + seq_printf(m, " %s: %10llx", + hist_data->fields[i]->field->name, + tracing_map_read_sum(elt, i)); + } else { + seq_printf(m, " %s: %10llu", + hist_data->fields[i]->field->name, + tracing_map_read_sum(elt, i)); + } } seq_puts(m, "\n"); @@ -816,9 +850,25 @@ const struct file_operations event_hist_fops = { .release = single_release, }; +static const char *get_hist_field_flags(struct hist_field *hist_field) +{ + const char *flags_str = NULL; + + if (hist_field->flags & HIST_FIELD_FL_HEX) + flags_str = "hex"; + + return flags_str; +} + static void hist_field_print(struct seq_file *m, struct hist_field *hist_field) { seq_printf(m, "%s", hist_field->field->name); + if (hist_field->flags) { + const char *flags_str = get_hist_field_flags(hist_field); + + if (flags_str) + seq_printf(m, ".%s", flags_str); + } } static int event_hist_trigger_print(struct seq_file *m, From c6afad49d127f6d7c9957319f55173a2198b1ba8 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:49 -0600 Subject: [PATCH 15/45] tracing: Add hist trigger 'sym' and 'sym-offset' modifiers Allow users to have address fields displayed as symbols in the output by appending '.sym' or 'sym-offset' to field names: # echo hist:keys=aaa.sym,bbb.sym-offset ... \ [ if filter] > event/trigger Link: http://lkml.kernel.org/r/87d4935821491c0275513f0fbfb9bab8d3d3f079.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 4 +++- kernel/trace/trace_events_hist.c | 29 +++++++++++++++++++++++++---- 2 files changed, 28 insertions(+), 5 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2eb2eafbe7f5..34459eb0c844 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3855,7 +3855,9 @@ static const char readme_msg[] = "\t table in its entirety to stdout. The default format used to\n" "\t display a given field can be modified by appending any of the\n" "\t following modifiers to the field name, as applicable:\n\n" - "\t .hex display a number as a hex value\n\n" + "\t .hex display a number as a hex value\n" + "\t .sym display an address as a symbol\n" + "\t .sym-offset display an address as a symbol and offset\n\n" "\t The 'pause' parameter can be used to pause an existing hist\n" "\t trigger or to start a hist trigger but not log any events\n" "\t until told to do so. 'continue' can be used to start or\n" diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 8e49eeef8867..808cc06cdb61 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -77,10 +77,12 @@ DEFINE_HIST_FIELD_FN(u8); #define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + sizeof(u64)) enum hist_field_flags { - HIST_FIELD_FL_HITCOUNT = 1, - HIST_FIELD_FL_KEY = 2, - HIST_FIELD_FL_STRING = 4, - HIST_FIELD_FL_HEX = 8, + HIST_FIELD_FL_HITCOUNT = 1, + HIST_FIELD_FL_KEY = 2, + HIST_FIELD_FL_STRING = 4, + HIST_FIELD_FL_HEX = 8, + HIST_FIELD_FL_SYM = 16, + HIST_FIELD_FL_SYM_OFFSET = 32, }; struct hist_trigger_attrs { @@ -397,6 +399,10 @@ static int create_key_field(struct hist_trigger_data *hist_data, if (field_str) { if (strcmp(field_str, "hex") == 0) flags |= HIST_FIELD_FL_HEX; + else if (strcmp(field_str, "sym") == 0) + flags |= HIST_FIELD_FL_SYM; + else if (strcmp(field_str, "sym-offset") == 0) + flags |= HIST_FIELD_FL_SYM_OFFSET; else { ret = -EINVAL; goto out; @@ -726,6 +732,7 @@ hist_trigger_entry_print(struct seq_file *m, struct tracing_map_elt *elt) { struct hist_field *key_field; + char str[KSYM_SYMBOL_LEN]; unsigned int i; u64 uval; @@ -741,6 +748,16 @@ hist_trigger_entry_print(struct seq_file *m, uval = *(u64 *)(key + key_field->offset); seq_printf(m, "%s: %llx", key_field->field->name, uval); + } else if (key_field->flags & HIST_FIELD_FL_SYM) { + uval = *(u64 *)(key + key_field->offset); + sprint_symbol_no_offset(str, uval); + seq_printf(m, "%s: [%llx] %-45s", + key_field->field->name, uval, str); + } else if (key_field->flags & HIST_FIELD_FL_SYM_OFFSET) { + uval = *(u64 *)(key + key_field->offset); + sprint_symbol(str, uval); + seq_printf(m, "%s: [%llx] %-55s", + key_field->field->name, uval, str); } else if (key_field->flags & HIST_FIELD_FL_STRING) { seq_printf(m, "%s: %-50s", key_field->field->name, (char *)(key + key_field->offset)); @@ -856,6 +873,10 @@ static const char *get_hist_field_flags(struct hist_field *hist_field) if (hist_field->flags & HIST_FIELD_FL_HEX) flags_str = "hex"; + else if (hist_field->flags & HIST_FIELD_FL_SYM) + flags_str = "sym"; + else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET) + flags_str = "sym-offset"; return flags_str; } From 6b4827ad028a1ab2fc4dcf1f5e6e077018d1b770 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:50 -0600 Subject: [PATCH 16/45] tracing: Add hist trigger 'execname' modifier Allow users to have common_pid field values displayed as program names in the output by appending '.execname' to a common_pid field name: # echo hist:keys=common_pid.execname ... \ [ if filter] > event/trigger Link: http://lkml.kernel.org/r/e172e81f10f5b8d1f08450e3763c850f39fbf698.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 3 +- kernel/trace/trace_events_hist.c | 100 ++++++++++++++++++++++++++++++- 2 files changed, 101 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 34459eb0c844..58a8bee50c6e 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3857,7 +3857,8 @@ static const char readme_msg[] = "\t following modifiers to the field name, as applicable:\n\n" "\t .hex display a number as a hex value\n" "\t .sym display an address as a symbol\n" - "\t .sym-offset display an address as a symbol and offset\n\n" + "\t .sym-offset display an address as a symbol and offset\n" + "\t .execname display a common_pid as a program name\n\n" "\t The 'pause' parameter can be used to pause an existing hist\n" "\t trigger or to start a hist trigger but not log any events\n" "\t until told to do so. 'continue' can be used to start or\n" diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 808cc06cdb61..227e6c21b1eb 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -83,6 +83,7 @@ enum hist_field_flags { HIST_FIELD_FL_HEX = 8, HIST_FIELD_FL_SYM = 16, HIST_FIELD_FL_SYM_OFFSET = 32, + HIST_FIELD_FL_EXECNAME = 64, }; struct hist_trigger_attrs { @@ -232,6 +233,73 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) return ERR_PTR(ret); } +static inline void save_comm(char *comm, struct task_struct *task) +{ + if (!task->pid) { + strcpy(comm, ""); + return; + } + + if (WARN_ON_ONCE(task->pid < 0)) { + strcpy(comm, ""); + return; + } + + memcpy(comm, task->comm, TASK_COMM_LEN); +} + +static void hist_trigger_elt_comm_free(struct tracing_map_elt *elt) +{ + kfree((char *)elt->private_data); +} + +static int hist_trigger_elt_comm_alloc(struct tracing_map_elt *elt) +{ + struct hist_trigger_data *hist_data = elt->map->private_data; + struct hist_field *key_field; + unsigned int i; + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + + if (key_field->flags & HIST_FIELD_FL_EXECNAME) { + unsigned int size = TASK_COMM_LEN + 1; + + elt->private_data = kzalloc(size, GFP_KERNEL); + if (!elt->private_data) + return -ENOMEM; + break; + } + } + + return 0; +} + +static void hist_trigger_elt_comm_copy(struct tracing_map_elt *to, + struct tracing_map_elt *from) +{ + char *comm_from = from->private_data; + char *comm_to = to->private_data; + + if (comm_from) + memcpy(comm_to, comm_from, TASK_COMM_LEN + 1); +} + +static void hist_trigger_elt_comm_init(struct tracing_map_elt *elt) +{ + char *comm = elt->private_data; + + if (comm) + save_comm(comm, current); +} + +static const struct tracing_map_ops hist_trigger_elt_comm_ops = { + .elt_alloc = hist_trigger_elt_comm_alloc, + .elt_copy = hist_trigger_elt_comm_copy, + .elt_free = hist_trigger_elt_comm_free, + .elt_init = hist_trigger_elt_comm_init, +}; + static void destroy_hist_field(struct hist_field *hist_field) { kfree(hist_field); @@ -403,6 +471,9 @@ static int create_key_field(struct hist_trigger_data *hist_data, flags |= HIST_FIELD_FL_SYM; else if (strcmp(field_str, "sym-offset") == 0) flags |= HIST_FIELD_FL_SYM_OFFSET; + else if ((strcmp(field_str, "execname") == 0) && + (strcmp(field_name, "common_pid") == 0)) + flags |= HIST_FIELD_FL_EXECNAME; else { ret = -EINVAL; goto out; @@ -624,11 +695,27 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data) return 0; } +static bool need_tracing_map_ops(struct hist_trigger_data *hist_data) +{ + struct hist_field *key_field; + unsigned int i; + + for_each_hist_key_field(i, hist_data) { + key_field = hist_data->fields[i]; + + if (key_field->flags & HIST_FIELD_FL_EXECNAME) + return true; + } + + return false; +} + static struct hist_trigger_data * create_hist_data(unsigned int map_bits, struct hist_trigger_attrs *attrs, struct trace_event_file *file) { + const struct tracing_map_ops *map_ops = NULL; struct hist_trigger_data *hist_data; int ret = 0; @@ -646,8 +733,11 @@ create_hist_data(unsigned int map_bits, if (ret) goto free; + if (need_tracing_map_ops(hist_data)) + map_ops = &hist_trigger_elt_comm_ops; + hist_data->map = tracing_map_create(map_bits, hist_data->key_size, - NULL, hist_data); + map_ops, hist_data); if (IS_ERR(hist_data->map)) { ret = PTR_ERR(hist_data->map); hist_data->map = NULL; @@ -758,6 +848,12 @@ hist_trigger_entry_print(struct seq_file *m, sprint_symbol(str, uval); seq_printf(m, "%s: [%llx] %-55s", key_field->field->name, uval, str); + } else if (key_field->flags & HIST_FIELD_FL_EXECNAME) { + char *comm = elt->private_data; + + uval = *(u64 *)(key + key_field->offset); + seq_printf(m, "%s: %-16s[%10llu]", + key_field->field->name, comm, uval); } else if (key_field->flags & HIST_FIELD_FL_STRING) { seq_printf(m, "%s: %-50s", key_field->field->name, (char *)(key + key_field->offset)); @@ -877,6 +973,8 @@ static const char *get_hist_field_flags(struct hist_field *hist_field) flags_str = "sym"; else if (hist_field->flags & HIST_FIELD_FL_SYM_OFFSET) flags_str = "sym-offset"; + else if (hist_field->flags & HIST_FIELD_FL_EXECNAME) + flags_str = "execname"; return flags_str; } From 316961988b5ec71bbf4b2ad447662770349aec13 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:51 -0600 Subject: [PATCH 17/45] tracing: Add hist trigger 'syscall' modifier Allow users to have syscall id fields displayed as syscall names in the output by appending '.syscall' to field names: # echo hist:keys=aaa.syscall ... \ [ if filter] > event/trigger Link: http://lkml.kernel.org/r/2bab1e59933d76a14b545bd2e02f80b8b08ac4d3.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 3 ++- kernel/trace/trace_events_hist.c | 15 +++++++++++++++ 2 files changed, 17 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 58a8bee50c6e..0dd23c5b1c34 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3858,7 +3858,8 @@ static const char readme_msg[] = "\t .hex display a number as a hex value\n" "\t .sym display an address as a symbol\n" "\t .sym-offset display an address as a symbol and offset\n" - "\t .execname display a common_pid as a program name\n\n" + "\t .execname display a common_pid as a program name\n" + "\t .syscall display a syscall id as a syscall name\n\n" "\t The 'pause' parameter can be used to pause an existing hist\n" "\t trigger or to start a hist trigger but not log any events\n" "\t until told to do so. 'continue' can be used to start or\n" diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 227e6c21b1eb..f9e7ecb33847 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -84,6 +84,7 @@ enum hist_field_flags { HIST_FIELD_FL_SYM = 16, HIST_FIELD_FL_SYM_OFFSET = 32, HIST_FIELD_FL_EXECNAME = 64, + HIST_FIELD_FL_SYSCALL = 128, }; struct hist_trigger_attrs { @@ -474,6 +475,8 @@ static int create_key_field(struct hist_trigger_data *hist_data, else if ((strcmp(field_str, "execname") == 0) && (strcmp(field_name, "common_pid") == 0)) flags |= HIST_FIELD_FL_EXECNAME; + else if (strcmp(field_str, "syscall") == 0) + flags |= HIST_FIELD_FL_SYSCALL; else { ret = -EINVAL; goto out; @@ -854,6 +857,16 @@ hist_trigger_entry_print(struct seq_file *m, uval = *(u64 *)(key + key_field->offset); seq_printf(m, "%s: %-16s[%10llu]", key_field->field->name, comm, uval); + } else if (key_field->flags & HIST_FIELD_FL_SYSCALL) { + const char *syscall_name; + + uval = *(u64 *)(key + key_field->offset); + syscall_name = get_syscall_name(uval); + if (!syscall_name) + syscall_name = "unknown_syscall"; + + seq_printf(m, "%s: %-30s[%3llu]", + key_field->field->name, syscall_name, uval); } else if (key_field->flags & HIST_FIELD_FL_STRING) { seq_printf(m, "%s: %-50s", key_field->field->name, (char *)(key + key_field->offset)); @@ -975,6 +988,8 @@ static const char *get_hist_field_flags(struct hist_field *hist_field) flags_str = "sym-offset"; else if (hist_field->flags & HIST_FIELD_FL_EXECNAME) flags_str = "execname"; + else if (hist_field->flags & HIST_FIELD_FL_SYSCALL) + flags_str = "syscall"; return flags_str; } From 69a0200c2e25d61c50091549d00cfeb426c258f5 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:52 -0600 Subject: [PATCH 18/45] tracing: Add hist trigger support for stacktraces as keys It's often useful to be able to use a stacktrace as a hash key, for keeping a count of the number of times a particular call path resulted in a trace event, for instance. Add a special key named 'stacktrace' which can be used as key in a 'keys=' param for this purpose: # echo hist:keys=stacktrace ... \ [ if filter] > event/trigger Link: http://lkml.kernel.org/r/87515e90b3785232a874a12156174635a348edb1.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 16 ++-- kernel/trace/trace_events_hist.c | 135 +++++++++++++++++++++++-------- 2 files changed, 109 insertions(+), 42 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 0dd23c5b1c34..2238bfde799b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3843,14 +3843,14 @@ static const char readme_msg[] = "\t table using the key(s) and value(s) named, and the value of a\n" "\t sum called 'hitcount' is incremented. Keys and values\n" "\t correspond to fields in the event's format description. Keys\n" - "\t can be any field. Compound keys consisting of up to two\n" - "\t fields can be specified by the 'keys' keyword. Values must\n" - "\t correspond to numeric fields. Sort keys consisting of up to\n" - "\t two fields can be specified using the 'sort' keyword. The\n" - "\t sort direction can be modified by appending '.descending' or\n" - "\t '.ascending' to a sort field. The 'size' parameter can be\n" - "\t used to specify more or fewer than the default 2048 entries\n" - "\t for the hashtable size.\n\n" + "\t can be any field, or the special string 'stacktrace'.\n" + "\t Compound keys consisting of up to two fields can be specified\n" + "\t by the 'keys' keyword. Values must correspond to numeric\n" + "\t fields. Sort keys consisting of up to two fields can be\n" + "\t specified using the 'sort' keyword. The sort direction can\n" + "\t be modified by appending '.descending' or '.ascending' to a\n" + "\t sort field. The 'size' parameter can be used to specify more\n" + "\t or fewer than the default 2048 entries for the hashtable size.\n\n" "\t Reading the 'hist' file for the event will dump the hash\n" "\t table in its entirety to stdout. The default format used to\n" "\t display a given field can be modified by appending any of the\n" diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index f9e7ecb33847..21cae42b54da 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -35,6 +35,11 @@ struct hist_field { unsigned int offset; }; +static u64 hist_field_none(struct hist_field *field, void *event) +{ + return 0; +} + static u64 hist_field_counter(struct hist_field *field, void *event) { return 1; @@ -73,8 +78,12 @@ DEFINE_HIST_FIELD_FN(u8); #define for_each_hist_key_field(i, hist_data) \ for ((i) = (hist_data)->n_vals; (i) < (hist_data)->n_fields; (i)++) +#define HIST_STACKTRACE_DEPTH 16 +#define HIST_STACKTRACE_SIZE (HIST_STACKTRACE_DEPTH * sizeof(unsigned long)) +#define HIST_STACKTRACE_SKIP 5 + #define HITCOUNT_IDX 0 -#define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + sizeof(u64)) +#define HIST_KEY_SIZE_MAX (MAX_FILTER_STR_VAL + HIST_STACKTRACE_SIZE) enum hist_field_flags { HIST_FIELD_FL_HITCOUNT = 1, @@ -85,6 +94,7 @@ enum hist_field_flags { HIST_FIELD_FL_SYM_OFFSET = 32, HIST_FIELD_FL_EXECNAME = 64, HIST_FIELD_FL_SYSCALL = 128, + HIST_FIELD_FL_STACKTRACE = 256, }; struct hist_trigger_attrs { @@ -323,6 +333,11 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, goto out; } + if (flags & HIST_FIELD_FL_STACKTRACE) { + hist_field->fn = hist_field_none; + goto out; + } + if (is_string_field(field)) { flags |= HIST_FIELD_FL_STRING; hist_field->fn = hist_field_string; @@ -456,7 +471,6 @@ static int create_key_field(struct hist_trigger_data *hist_data, struct ftrace_event_field *field = NULL; unsigned long flags = 0; unsigned int key_size; - char *field_name; int ret = 0; if (WARN_ON(key_idx >= TRACING_MAP_FIELDS_MAX)) @@ -464,33 +478,39 @@ static int create_key_field(struct hist_trigger_data *hist_data, flags |= HIST_FIELD_FL_KEY; - field_name = strsep(&field_str, "."); - if (field_str) { - if (strcmp(field_str, "hex") == 0) - flags |= HIST_FIELD_FL_HEX; - else if (strcmp(field_str, "sym") == 0) - flags |= HIST_FIELD_FL_SYM; - else if (strcmp(field_str, "sym-offset") == 0) - flags |= HIST_FIELD_FL_SYM_OFFSET; - else if ((strcmp(field_str, "execname") == 0) && - (strcmp(field_name, "common_pid") == 0)) - flags |= HIST_FIELD_FL_EXECNAME; - else if (strcmp(field_str, "syscall") == 0) - flags |= HIST_FIELD_FL_SYSCALL; - else { + if (strcmp(field_str, "stacktrace") == 0) { + flags |= HIST_FIELD_FL_STACKTRACE; + key_size = sizeof(unsigned long) * HIST_STACKTRACE_DEPTH; + } else { + char *field_name = strsep(&field_str, "."); + + if (field_str) { + if (strcmp(field_str, "hex") == 0) + flags |= HIST_FIELD_FL_HEX; + else if (strcmp(field_str, "sym") == 0) + flags |= HIST_FIELD_FL_SYM; + else if (strcmp(field_str, "sym-offset") == 0) + flags |= HIST_FIELD_FL_SYM_OFFSET; + else if ((strcmp(field_str, "execname") == 0) && + (strcmp(field_name, "common_pid") == 0)) + flags |= HIST_FIELD_FL_EXECNAME; + else if (strcmp(field_str, "syscall") == 0) + flags |= HIST_FIELD_FL_SYSCALL; + else { + ret = -EINVAL; + goto out; + } + } + + field = trace_find_event_field(file->event_call, field_name); + if (!field) { ret = -EINVAL; goto out; } - } - field = trace_find_event_field(file->event_call, field_name); - if (!field) { - ret = -EINVAL; - goto out; + key_size = field->size; } - key_size = field->size; - hist_data->fields[key_idx] = create_hist_field(field, flags); if (!hist_data->fields[key_idx]) { ret = -ENOMEM; @@ -679,7 +699,9 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data) field = hist_field->field; - if (is_string_field(field)) + if (hist_field->flags & HIST_FIELD_FL_STACKTRACE) + cmp_fn = tracing_map_cmp_none; + else if (is_string_field(field)) cmp_fn = tracing_map_cmp_string; else cmp_fn = tracing_map_cmp_num(field->size, @@ -786,7 +808,9 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, static void event_hist_trigger(struct event_trigger_data *data, void *rec) { struct hist_trigger_data *hist_data = data->private_data; + unsigned long entries[HIST_STACKTRACE_DEPTH]; char compound_key[HIST_KEY_SIZE_MAX]; + struct stack_trace stacktrace; struct hist_field *key_field; struct tracing_map_elt *elt; u64 field_contents; @@ -799,15 +823,27 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec) for_each_hist_key_field(i, hist_data) { key_field = hist_data->fields[i]; - field_contents = key_field->fn(key_field, rec); - if (key_field->flags & HIST_FIELD_FL_STRING) - key = (void *)(unsigned long)field_contents; - else - key = (void *)&field_contents; + if (key_field->flags & HIST_FIELD_FL_STACKTRACE) { + stacktrace.max_entries = HIST_STACKTRACE_DEPTH; + stacktrace.entries = entries; + stacktrace.nr_entries = 0; + stacktrace.skip = HIST_STACKTRACE_SKIP; - if (hist_data->n_keys > 1) { - memcpy(compound_key + key_field->offset, key, - key_field->size); + memset(stacktrace.entries, 0, HIST_STACKTRACE_SIZE); + save_stack_trace(&stacktrace); + + key = entries; + } else { + field_contents = key_field->fn(key_field, rec); + if (key_field->flags & HIST_FIELD_FL_STRING) + key = (void *)(unsigned long)field_contents; + else + key = (void *)&field_contents; + + if (hist_data->n_keys > 1) { + memcpy(compound_key + key_field->offset, key, + key_field->size); + } } } @@ -819,6 +855,24 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec) hist_trigger_elt_update(hist_data, elt, rec); } +static void hist_trigger_stacktrace_print(struct seq_file *m, + unsigned long *stacktrace_entries, + unsigned int max_entries) +{ + char str[KSYM_SYMBOL_LEN]; + unsigned int spaces = 8; + unsigned int i; + + for (i = 0; i < max_entries; i++) { + if (stacktrace_entries[i] == ULONG_MAX) + return; + + seq_printf(m, "%*c", 1 + spaces, ' '); + sprint_symbol(str, stacktrace_entries[i]); + seq_printf(m, "%s\n", str); + } +} + static void hist_trigger_entry_print(struct seq_file *m, struct hist_trigger_data *hist_data, void *key, @@ -826,6 +880,7 @@ hist_trigger_entry_print(struct seq_file *m, { struct hist_field *key_field; char str[KSYM_SYMBOL_LEN]; + bool multiline = false; unsigned int i; u64 uval; @@ -867,6 +922,12 @@ hist_trigger_entry_print(struct seq_file *m, seq_printf(m, "%s: %-30s[%3llu]", key_field->field->name, syscall_name, uval); + } else if (key_field->flags & HIST_FIELD_FL_STACKTRACE) { + seq_puts(m, "stacktrace:\n"); + hist_trigger_stacktrace_print(m, + key + key_field->offset, + HIST_STACKTRACE_DEPTH); + multiline = true; } else if (key_field->flags & HIST_FIELD_FL_STRING) { seq_printf(m, "%s: %-50s", key_field->field->name, (char *)(key + key_field->offset)); @@ -877,7 +938,10 @@ hist_trigger_entry_print(struct seq_file *m, } } - seq_puts(m, " }"); + if (!multiline) + seq_puts(m, " "); + + seq_puts(m, "}"); seq_printf(m, " hitcount: %10llu", tracing_map_read_sum(elt, HITCOUNT_IDX)); @@ -1021,7 +1085,10 @@ static int event_hist_trigger_print(struct seq_file *m, if (i > hist_data->n_vals) seq_puts(m, ","); - hist_field_print(m, key_field); + if (key_field->flags & HIST_FIELD_FL_STACKTRACE) + seq_puts(m, "stacktrace"); + else + hist_field_print(m, key_field); } seq_puts(m, ":vals="); From 79e577cbce4c4c2bf0d64ec315adb04eda40736b Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Thu, 3 Mar 2016 12:54:53 -0600 Subject: [PATCH 19/45] tracing: Support string type key properly The string in a trace event is usually recorded as dynamic array which is variable length. But current hist code only support fixed length array so it cannot support most strings. This patch fixes it by checking filter_type of the field and get proper pointer with it. With this, it can get a histogram of exec() based on filenames like below: # cd /sys/kernel/tracing/events/sched/sched_process_exec # cat 'hist:key=filename' > trigger # ps PID TTY TIME CMD 1 ? 00:00:00 init 29 ? 00:00:00 sh 38 ? 00:00:00 ps # ls enable filter format hist id trigger # cat hist # trigger info: hist:keys=filename:vals=hitcount:sort=hitcount:size=2048 [active] { filename: /usr/bin/ps } hitcount: 1 { filename: /usr/bin/ls } hitcount: 1 { filename: /usr/bin/cat } hitcount: 1 Totals: Hits: 3 Entries: 3 Dropped: 0 Link: http://lkml.kernel.org/r/610180d6df0cfdf11ee205452f3b241dea657233.1457029949.git.tom.zanussi@linux.intel.com Cc: Tom Zanussi Cc: Masami Hiramatsu Signed-off-by: Namhyung Kim Tested-by: Masami Hiramatsu [ Added (unsigned long) typecast to fix compile warning ] Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_hist.c | 49 +++++++++++++++++++++++++++++--- 1 file changed, 45 insertions(+), 4 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 21cae42b54da..418ff27cbbaf 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -52,12 +52,28 @@ static u64 hist_field_string(struct hist_field *hist_field, void *event) return (u64)(unsigned long)addr; } +static u64 hist_field_dynstring(struct hist_field *hist_field, void *event) +{ + u32 str_item = *(u32 *)(event + hist_field->field->offset); + int str_loc = str_item & 0xffff; + char *addr = (char *)(event + str_loc); + + return (u64)(unsigned long)addr; +} + +static u64 hist_field_pstring(struct hist_field *hist_field, void *event) +{ + char **addr = (char **)(event + hist_field->field->offset); + + return (u64)(unsigned long)*addr; +} + #define DEFINE_HIST_FIELD_FN(type) \ static u64 hist_field_##type(struct hist_field *hist_field, void *event)\ { \ type *addr = (type *)(event + hist_field->field->offset); \ \ - return (u64)*addr; \ + return (u64)(unsigned long)*addr; \ } DEFINE_HIST_FIELD_FN(s64); @@ -340,7 +356,13 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, if (is_string_field(field)) { flags |= HIST_FIELD_FL_STRING; - hist_field->fn = hist_field_string; + + if (field->filter_type == FILTER_STATIC_STRING) + hist_field->fn = hist_field_string; + else if (field->filter_type == FILTER_DYN_STRING) + hist_field->fn = hist_field_dynstring; + else + hist_field->fn = hist_field_pstring; } else { hist_field->fn = select_value_fn(field->size, field->is_signed); @@ -508,7 +530,10 @@ static int create_key_field(struct hist_trigger_data *hist_data, goto out; } - key_size = field->size; + if (is_string_field(field)) /* should be last key field */ + key_size = HIST_KEY_SIZE_MAX - key_offset; + else + key_size = field->size; } hist_data->fields[key_idx] = create_hist_field(field, flags); @@ -841,8 +866,24 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec) key = (void *)&field_contents; if (hist_data->n_keys > 1) { + /* ensure NULL-termination */ + size_t size = key_field->size - 1; + + if (key_field->flags & HIST_FIELD_FL_STRING) { + struct ftrace_event_field *field; + + field = key_field->field; + if (field->filter_type == FILTER_DYN_STRING) + size = *(u32 *)(rec + field->offset) >> 16; + else if (field->filter_type == FILTER_PTR_STRING) + size = strlen(key); + + if (size > key_field->size - 1) + size = key_field->size - 1; + } + memcpy(compound_key + key_field->offset, key, - key_field->size); + size); } } } From 6a475cb17fe161dbde62eca7e4c2cf59edff182f Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:54 -0600 Subject: [PATCH 20/45] tracing: Remove restriction on string position in hist trigger keys If we assume the maximum size for a string field, we don't have to worry about its position. Since we only allow two keys in a compound key and having more than one string key in a given compound key doesn't make much sense anyway, trading a bit of extra space instead of introducing an arbitrary restriction makes more sense. We also need to use the event field size for static strings when copying the contents, otherwise we get random garbage in the key. Also, cast string return values to avoid warnings on 32-bit compiles. Finally, rearrange the code without changing any functionality by moving the compound key updating code into a separate function. Link: http://lkml.kernel.org/r/8976e1ab04b66bc2700ad1ed0768a2de85ac1983.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_hist.c | 63 ++++++++++++++++++-------------- 1 file changed, 35 insertions(+), 28 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 418ff27cbbaf..4f4041d76926 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -530,8 +530,8 @@ static int create_key_field(struct hist_trigger_data *hist_data, goto out; } - if (is_string_field(field)) /* should be last key field */ - key_size = HIST_KEY_SIZE_MAX - key_offset; + if (is_string_field(field)) + key_size = MAX_FILTER_STR_VAL; else key_size = field->size; } @@ -830,9 +830,34 @@ static void hist_trigger_elt_update(struct hist_trigger_data *hist_data, } } +static inline void add_to_key(char *compound_key, void *key, + struct hist_field *key_field, void *rec) +{ + size_t size = key_field->size; + + if (key_field->flags & HIST_FIELD_FL_STRING) { + struct ftrace_event_field *field; + + field = key_field->field; + if (field->filter_type == FILTER_DYN_STRING) + size = *(u32 *)(rec + field->offset) >> 16; + else if (field->filter_type == FILTER_PTR_STRING) + size = strlen(key); + else if (field->filter_type == FILTER_STATIC_STRING) + size = field->size; + + /* ensure NULL-termination */ + if (size > key_field->size - 1) + size = key_field->size - 1; + } + + memcpy(compound_key + key_field->offset, key, size); +} + static void event_hist_trigger(struct event_trigger_data *data, void *rec) { struct hist_trigger_data *hist_data = data->private_data; + bool use_compound_key = (hist_data->n_keys > 1); unsigned long entries[HIST_STACKTRACE_DEPTH]; char compound_key[HIST_KEY_SIZE_MAX]; struct stack_trace stacktrace; @@ -842,8 +867,7 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec) void *key = NULL; unsigned int i; - if (hist_data->n_keys > 1) - memset(compound_key, 0, hist_data->key_size); + memset(compound_key, 0, hist_data->key_size); for_each_hist_key_field(i, hist_data) { key_field = hist_data->fields[i]; @@ -860,35 +884,18 @@ static void event_hist_trigger(struct event_trigger_data *data, void *rec) key = entries; } else { field_contents = key_field->fn(key_field, rec); - if (key_field->flags & HIST_FIELD_FL_STRING) + if (key_field->flags & HIST_FIELD_FL_STRING) { key = (void *)(unsigned long)field_contents; - else + use_compound_key = true; + } else key = (void *)&field_contents; - - if (hist_data->n_keys > 1) { - /* ensure NULL-termination */ - size_t size = key_field->size - 1; - - if (key_field->flags & HIST_FIELD_FL_STRING) { - struct ftrace_event_field *field; - - field = key_field->field; - if (field->filter_type == FILTER_DYN_STRING) - size = *(u32 *)(rec + field->offset) >> 16; - else if (field->filter_type == FILTER_PTR_STRING) - size = strlen(key); - - if (size > key_field->size - 1) - size = key_field->size - 1; - } - - memcpy(compound_key + key_field->offset, key, - size); - } } + + if (use_compound_key) + add_to_key(compound_key, key, key_field, rec); } - if (hist_data->n_keys > 1) + if (use_compound_key) key = compound_key; elt = tracing_map_insert(hist_data->map, key); From d0bad49bb0a094a1beb06640785f95cb256b7272 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:55 -0600 Subject: [PATCH 21/45] tracing: Add enable_hist/disable_hist triggers Similar to enable_event/disable_event triggers, these triggers enable and disable the aggregation of events into maps rather than enabling and disabling their writing into the trace buffer. They can be used to automatically start and stop hist triggers based on a matching filter condition. If there's a paused hist trigger on system:event, the following would start it when the filter condition was hit: # echo enable_hist:system:event [ if filter] > event/trigger And the following would disable a running system:event hist trigger: # echo disable_hist:system:event [ if filter] > event/trigger See Documentation/trace/events.txt for real examples. Link: http://lkml.kernel.org/r/f812f086e52c8b7c8ad5443487375e03c96a601f.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- include/linux/trace_events.h | 1 + kernel/trace/trace.c | 8 ++ kernel/trace/trace.h | 32 ++++++++ kernel/trace/trace_events_hist.c | 115 ++++++++++++++++++++++++++++ kernel/trace/trace_events_trigger.c | 71 +++++++++-------- 5 files changed, 196 insertions(+), 31 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 404603720650..5f89a5b0c7e6 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -408,6 +408,7 @@ enum event_trigger_type { ETT_STACKTRACE = (1 << 2), ETT_EVENT_ENABLE = (1 << 3), ETT_EVENT_HIST = (1 << 4), + ETT_HIST_ENABLE = (1 << 5), }; extern int filter_match_preds(struct event_filter *filter, void *rec); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 2238bfde799b..8430145bea12 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3807,6 +3807,10 @@ static const char readme_msg[] = "\t trigger: traceon, traceoff\n" "\t enable_event::\n" "\t disable_event::\n" +#ifdef CONFIG_HIST_TRIGGERS + "\t enable_hist::\n" + "\t disable_hist::\n" +#endif #ifdef CONFIG_STACKTRACE "\t\t stacktrace\n" #endif @@ -3867,6 +3871,10 @@ static const char readme_msg[] = "\t The 'clear' parameter will clear the contents of a running\n" "\t hist trigger and leave its current paused/active state\n" "\t unchanged.\n\n" + "\t The enable_hist and disable_hist triggers can be used to\n" + "\t have one event conditionally start and stop another event's\n" + "\t already-attached hist trigger. The syntax is analagous to\n" + "\t the enable_event and disable_event triggers.\n" #endif ; diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 505f8a45f426..cab1f4bfe85b 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1166,8 +1166,10 @@ extern const struct file_operations event_hist_fops; #ifdef CONFIG_HIST_TRIGGERS extern int register_trigger_hist_cmd(void); +extern int register_trigger_hist_enable_disable_cmds(void); #else static inline int register_trigger_hist_cmd(void) { return 0; } +static inline int register_trigger_hist_enable_disable_cmds(void) { return 0; } #endif extern int register_trigger_cmds(void); @@ -1185,6 +1187,34 @@ struct event_trigger_data { struct list_head list; }; +/* Avoid typos */ +#define ENABLE_EVENT_STR "enable_event" +#define DISABLE_EVENT_STR "disable_event" +#define ENABLE_HIST_STR "enable_hist" +#define DISABLE_HIST_STR "disable_hist" + +struct enable_trigger_data { + struct trace_event_file *file; + bool enable; + bool hist; +}; + +extern int event_enable_trigger_print(struct seq_file *m, + struct event_trigger_ops *ops, + struct event_trigger_data *data); +extern void event_enable_trigger_free(struct event_trigger_ops *ops, + struct event_trigger_data *data); +extern int event_enable_trigger_func(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, char *cmd, char *param); +extern int event_enable_register_trigger(char *glob, + struct event_trigger_ops *ops, + struct event_trigger_data *data, + struct trace_event_file *file); +extern void event_enable_unregister_trigger(char *glob, + struct event_trigger_ops *ops, + struct event_trigger_data *test, + struct trace_event_file *file); extern void trigger_data_free(struct event_trigger_data *data); extern int event_trigger_init(struct event_trigger_ops *ops, struct event_trigger_data *data); @@ -1198,6 +1228,8 @@ extern int set_trigger_filter(char *filter_str, struct event_trigger_data *trigger_data, struct trace_event_file *file); extern int register_event_command(struct event_command *cmd); +extern int unregister_event_command(struct event_command *cmd); +extern int register_trigger_hist_enable_disable_cmds(void); /** * struct event_trigger_ops - callbacks for trace event triggers diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 4f4041d76926..5d4f02792440 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1393,3 +1393,118 @@ __init int register_trigger_hist_cmd(void) return ret; } + +static void +hist_enable_trigger(struct event_trigger_data *data, void *rec) +{ + struct enable_trigger_data *enable_data = data->private_data; + struct event_trigger_data *test; + + list_for_each_entry_rcu(test, &enable_data->file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (enable_data->enable) + test->paused = false; + else + test->paused = true; + break; + } + } +} + +static void +hist_enable_count_trigger(struct event_trigger_data *data, void *rec) +{ + if (!data->count) + return; + + if (data->count != -1) + (data->count)--; + + hist_enable_trigger(data, rec); +} + +static struct event_trigger_ops hist_enable_trigger_ops = { + .func = hist_enable_trigger, + .print = event_enable_trigger_print, + .init = event_trigger_init, + .free = event_enable_trigger_free, +}; + +static struct event_trigger_ops hist_enable_count_trigger_ops = { + .func = hist_enable_count_trigger, + .print = event_enable_trigger_print, + .init = event_trigger_init, + .free = event_enable_trigger_free, +}; + +static struct event_trigger_ops hist_disable_trigger_ops = { + .func = hist_enable_trigger, + .print = event_enable_trigger_print, + .init = event_trigger_init, + .free = event_enable_trigger_free, +}; + +static struct event_trigger_ops hist_disable_count_trigger_ops = { + .func = hist_enable_count_trigger, + .print = event_enable_trigger_print, + .init = event_trigger_init, + .free = event_enable_trigger_free, +}; + +static struct event_trigger_ops * +hist_enable_get_trigger_ops(char *cmd, char *param) +{ + struct event_trigger_ops *ops; + bool enable; + + enable = (strcmp(cmd, ENABLE_HIST_STR) == 0); + + if (enable) + ops = param ? &hist_enable_count_trigger_ops : + &hist_enable_trigger_ops; + else + ops = param ? &hist_disable_count_trigger_ops : + &hist_disable_trigger_ops; + + return ops; +} + +static struct event_command trigger_hist_enable_cmd = { + .name = ENABLE_HIST_STR, + .trigger_type = ETT_HIST_ENABLE, + .func = event_enable_trigger_func, + .reg = event_enable_register_trigger, + .unreg = event_enable_unregister_trigger, + .get_trigger_ops = hist_enable_get_trigger_ops, + .set_filter = set_trigger_filter, +}; + +static struct event_command trigger_hist_disable_cmd = { + .name = DISABLE_HIST_STR, + .trigger_type = ETT_HIST_ENABLE, + .func = event_enable_trigger_func, + .reg = event_enable_register_trigger, + .unreg = event_enable_unregister_trigger, + .get_trigger_ops = hist_enable_get_trigger_ops, + .set_filter = set_trigger_filter, +}; + +static __init void unregister_trigger_hist_enable_disable_cmds(void) +{ + unregister_event_command(&trigger_hist_enable_cmd); + unregister_event_command(&trigger_hist_disable_cmd); +} + +__init int register_trigger_hist_enable_disable_cmds(void) +{ + int ret; + + ret = register_event_command(&trigger_hist_enable_cmd); + if (WARN_ON(ret < 0)) + return ret; + ret = register_event_command(&trigger_hist_disable_cmd); + if (WARN_ON(ret < 0)) + unregister_trigger_hist_enable_disable_cmds(); + + return ret; +} diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index d29092afe005..d133f2094566 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -347,7 +347,7 @@ __init int register_event_command(struct event_command *cmd) * Currently we only unregister event commands from __init, so mark * this __init too. */ -static __init int unregister_event_command(struct event_command *cmd) +__init int unregister_event_command(struct event_command *cmd) { struct event_command *p, *n; int ret = -ENODEV; @@ -1062,15 +1062,6 @@ static __init void unregister_trigger_traceon_traceoff_cmds(void) unregister_event_command(&trigger_traceoff_cmd); } -/* Avoid typos */ -#define ENABLE_EVENT_STR "enable_event" -#define DISABLE_EVENT_STR "disable_event" - -struct enable_trigger_data { - struct trace_event_file *file; - bool enable; -}; - static void event_enable_trigger(struct event_trigger_data *data, void *rec) { @@ -1100,14 +1091,16 @@ event_enable_count_trigger(struct event_trigger_data *data, void *rec) event_enable_trigger(data, rec); } -static int -event_enable_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, - struct event_trigger_data *data) +int event_enable_trigger_print(struct seq_file *m, + struct event_trigger_ops *ops, + struct event_trigger_data *data) { struct enable_trigger_data *enable_data = data->private_data; seq_printf(m, "%s:%s:%s", - enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR, + enable_data->hist ? + (enable_data->enable ? ENABLE_HIST_STR : DISABLE_HIST_STR) : + (enable_data->enable ? ENABLE_EVENT_STR : DISABLE_EVENT_STR), enable_data->file->event_call->class->system, trace_event_name(enable_data->file->event_call)); @@ -1124,9 +1117,8 @@ event_enable_trigger_print(struct seq_file *m, struct event_trigger_ops *ops, return 0; } -static void -event_enable_trigger_free(struct event_trigger_ops *ops, - struct event_trigger_data *data) +void event_enable_trigger_free(struct event_trigger_ops *ops, + struct event_trigger_data *data) { struct enable_trigger_data *enable_data = data->private_data; @@ -1171,10 +1163,9 @@ static struct event_trigger_ops event_disable_count_trigger_ops = { .free = event_enable_trigger_free, }; -static int -event_enable_trigger_func(struct event_command *cmd_ops, - struct trace_event_file *file, - char *glob, char *cmd, char *param) +int event_enable_trigger_func(struct event_command *cmd_ops, + struct trace_event_file *file, + char *glob, char *cmd, char *param) { struct trace_event_file *event_enable_file; struct enable_trigger_data *enable_data; @@ -1183,6 +1174,7 @@ event_enable_trigger_func(struct event_command *cmd_ops, struct trace_array *tr = file->tr; const char *system; const char *event; + bool hist = false; char *trigger; char *number; bool enable; @@ -1207,8 +1199,15 @@ event_enable_trigger_func(struct event_command *cmd_ops, if (!event_enable_file) goto out; - enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; +#ifdef CONFIG_HIST_TRIGGERS + hist = ((strcmp(cmd, ENABLE_HIST_STR) == 0) || + (strcmp(cmd, DISABLE_HIST_STR) == 0)); + enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) || + (strcmp(cmd, ENABLE_HIST_STR) == 0)); +#else + enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; +#endif trigger_ops = cmd_ops->get_trigger_ops(cmd, trigger); ret = -ENOMEM; @@ -1228,6 +1227,7 @@ event_enable_trigger_func(struct event_command *cmd_ops, INIT_LIST_HEAD(&trigger_data->list); RCU_INIT_POINTER(trigger_data->filter, NULL); + enable_data->hist = hist; enable_data->enable = enable; enable_data->file = event_enable_file; trigger_data->private_data = enable_data; @@ -1305,10 +1305,10 @@ event_enable_trigger_func(struct event_command *cmd_ops, goto out; } -static int event_enable_register_trigger(char *glob, - struct event_trigger_ops *ops, - struct event_trigger_data *data, - struct trace_event_file *file) +int event_enable_register_trigger(char *glob, + struct event_trigger_ops *ops, + struct event_trigger_data *data, + struct trace_event_file *file) { struct enable_trigger_data *enable_data = data->private_data; struct enable_trigger_data *test_enable_data; @@ -1318,6 +1318,8 @@ static int event_enable_register_trigger(char *glob, list_for_each_entry_rcu(test, &file->triggers, list) { test_enable_data = test->private_data; if (test_enable_data && + (test->cmd_ops->trigger_type == + data->cmd_ops->trigger_type) && (test_enable_data->file == enable_data->file)) { ret = -EEXIST; goto out; @@ -1343,10 +1345,10 @@ static int event_enable_register_trigger(char *glob, return ret; } -static void event_enable_unregister_trigger(char *glob, - struct event_trigger_ops *ops, - struct event_trigger_data *test, - struct trace_event_file *file) +void event_enable_unregister_trigger(char *glob, + struct event_trigger_ops *ops, + struct event_trigger_data *test, + struct trace_event_file *file) { struct enable_trigger_data *test_enable_data = test->private_data; struct enable_trigger_data *enable_data; @@ -1356,6 +1358,8 @@ static void event_enable_unregister_trigger(char *glob, list_for_each_entry_rcu(data, &file->triggers, list) { enable_data = data->private_data; if (enable_data && + (data->cmd_ops->trigger_type == + test->cmd_ops->trigger_type) && (enable_data->file == test_enable_data->file)) { unregistered = true; list_del_rcu(&data->list); @@ -1375,8 +1379,12 @@ event_enable_get_trigger_ops(char *cmd, char *param) struct event_trigger_ops *ops; bool enable; +#ifdef CONFIG_HIST_TRIGGERS + enable = ((strcmp(cmd, ENABLE_EVENT_STR) == 0) || + (strcmp(cmd, ENABLE_HIST_STR) == 0)); +#else enable = strcmp(cmd, ENABLE_EVENT_STR) == 0; - +#endif if (enable) ops = param ? &event_enable_count_trigger_ops : &event_enable_trigger_ops; @@ -1447,6 +1455,7 @@ __init int register_trigger_cmds(void) register_trigger_snapshot_cmd(); register_trigger_stacktrace_cmd(); register_trigger_enable_disable_cmds(); + register_trigger_hist_enable_disable_cmds(); register_trigger_hist_cmd(); return 0; From 0fc3813ce1036b57598ee5cdcf891f8a19581654 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:56 -0600 Subject: [PATCH 22/45] tracing: Add 'hist' trigger Documentation Add documentation and usage examples for 'hist' triggers. Link: http://lkml.kernel.org/r/2e13f35f47fea6d647f0efefccfc9673ea84b29f.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- Documentation/trace/events.txt | 1155 ++++++++++++++++++++++++++++++++ 1 file changed, 1155 insertions(+) diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt index c010be8c85d7..db223e85bd2f 100644 --- a/Documentation/trace/events.txt +++ b/Documentation/trace/events.txt @@ -512,3 +512,1158 @@ The following commands are supported: Note that there can be only one traceon or traceoff trigger per triggering event. + +- hist + + This command aggregates event hits into a hash table keyed on one or + more trace event format fields (or stacktrace) and a set of running + totals derived from one or more trace event format fields and/or + event counts (hitcount). + + The format of a hist trigger is as follows: + + hist:keys=[:values=] + [:sort=][:size=#entries][:pause][:continue] + [:clear] [if ] + + When a matching event is hit, an entry is added to a hash table + using the key(s) and value(s) named. Keys and values correspond to + fields in the event's format description. Values must correspond to + numeric fields - on an event hit, the value(s) will be added to a + sum kept for that field. The special string 'hitcount' can be used + in place of an explicit value field - this is simply a count of + event hits. If 'values' isn't specified, an implicit 'hitcount' + value will be automatically created and used as the only value. + Keys can be any field, or the special string 'stacktrace', which + will use the event's kernel stacktrace as the key. The keywords + 'keys' or 'key' can be used to specify keys, and the keywords + 'values', 'vals', or 'val' can be used to specify values. Compound + keys consisting of up to two fields can be specified by the 'keys' + keyword. Hashing a compound key produces a unique entry in the + table for each unique combination of component keys, and can be + useful for providing more fine-grained summaries of event data. + Additionally, sort keys consisting of up to two fields can be + specified by the 'sort' keyword. If more than one field is + specified, the result will be a 'sort within a sort': the first key + is taken to be the primary sort key and the second the secondary + key. + + 'hist' triggers add a 'hist' file to each event's subdirectory. + Reading the 'hist' file for the event will dump the hash table in + its entirety to stdout. Each printed hash table entry is a simple + list of the keys and values comprising the entry; keys are printed + first and are delineated by curly braces, and are followed by the + set of value fields for the entry. By default, numeric fields are + displayed as base-10 integers. This can be modified by appending + any of the following modifiers to the field name: + + .hex display a number as a hex value + .sym display an address as a symbol + .sym-offset display an address as a symbol and offset + .syscall display a syscall id as a system call name + .execname display a common_pid as a program name + + Note that in general the semantics of a given field aren't + interpreted when applying a modifier to it, but there are some + restrictions to be aware of in this regard: + + - only the 'hex' modifier can be used for values (because values + are essentially sums, and the other modifiers don't make sense + in that context). + - the 'execname' modifier can only be used on a 'common_pid'. The + reason for this is that the execname is simply the 'comm' value + saved for the 'current' process when an event was triggered, + which is the same as the common_pid value saved by the event + tracing code. Trying to apply that comm value to other pid + values wouldn't be correct, and typically events that care save + pid-specific comm fields in the event itself. + + A typical usage scenario would be the following to enable a hist + trigger, read its current contents, and then turn it off: + + # echo 'hist:keys=skbaddr.hex:vals=len' > \ + /sys/kernel/debug/tracing/events/net/netif_rx/trigger + + # cat /sys/kernel/debug/tracing/events/net/netif_rx/hist + + # echo '!hist:keys=skbaddr.hex:vals=len' > \ + /sys/kernel/debug/tracing/events/net/netif_rx/trigger + + The trigger file itself can be read to show the details of the + currently attached hist trigger. This information is also displayed + at the top of the 'hist' file when read. + + By default, the size of the hash table is 2048 entries. The 'size' + parameter can be used to specify more or fewer than that. The units + are in terms of hashtable entries - if a run uses more entries than + specified, the results will show the number of 'drops', the number + of hits that were ignored. The size should be a power of 2 between + 128 and 131072 (any non- power-of-2 number specified will be rounded + up). + + The 'sort' parameter can be used to specify a value field to sort + on. The default if unspecified is 'hitcount' and the default sort + order is 'ascending'. To sort in the opposite direction, append + .descending' to the sort key. + + The 'pause' parameter can be used to pause an existing hist trigger + or to start a hist trigger but not log any events until told to do + so. 'continue' or 'cont' can be used to start or restart a paused + hist trigger. + + The 'clear' parameter will clear the contents of a running hist + trigger and leave its current paused/active state. + + Note that the 'pause', 'cont', and 'clear' parameters should be + applied using 'append' shell operator ('>>') if applied to an + existing trigger, rather than via the '>' operator, which will cause + the trigger to be removed through truncation. + +- enable_hist/disable_hist + + The enable_hist and disable_hist triggers can be used to have one + event conditionally start and stop another event's already-attached + hist trigger. Any number of enable_hist and disable_hist triggers + can be attached to a given event, allowing that event to kick off + and stop aggregations on a host of other events. + + The format is very similar to the enable/disable_event triggers: + + enable_hist::[:count] + disable_hist::[:count] + + Instead of enabling or disabling the tracing of the target event + into the trace buffer as the enable/disable_event triggers do, the + enable/disable_hist triggers enable or disable the aggregation of + the target event into a hash table. + + A typical usage scenario for the enable_hist/disable_hist triggers + would be to first set up a paused hist trigger on some event, + followed by an enable_hist/disable_hist pair that turns the hist + aggregation on and off when conditions of interest are hit: + + # echo 'hist:keys=skbaddr.hex:vals=len:pause' > \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + + # echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger + + # echo 'disable_hist:net:netif_receive_skb if comm==wget' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger + + The above sets up an initially paused hist trigger which is unpaused + and starts aggregating events when a given program is executed, and + which stops aggregating when the process exits and the hist trigger + is paused again. + + The examples below provide a more concrete illustration of the + concepts and typical usage patterns discussed above. + + +6.2 'hist' trigger examples +--------------------------- + + The first set of examples creates aggregations using the kmalloc + event. The fields that can be used for the hist trigger are listed + in the kmalloc event's format file: + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/format + name: kmalloc + ID: 374 + format: + field:unsigned short common_type; offset:0; size:2; signed:0; + field:unsigned char common_flags; offset:2; size:1; signed:0; + field:unsigned char common_preempt_count; offset:3; size:1; signed:0; + field:int common_pid; offset:4; size:4; signed:1; + + field:unsigned long call_site; offset:8; size:8; signed:0; + field:const void * ptr; offset:16; size:8; signed:0; + field:size_t bytes_req; offset:24; size:8; signed:0; + field:size_t bytes_alloc; offset:32; size:8; signed:0; + field:gfp_t gfp_flags; offset:40; size:4; signed:0; + + We'll start by creating a hist trigger that generates a simple table + that lists the total number of bytes requested for each function in + the kernel that made one or more calls to kmalloc: + + # echo 'hist:key=call_site:val=bytes_req' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + This tells the tracing system to create a 'hist' trigger using the + call_site field of the kmalloc event as the key for the table, which + just means that each unique call_site address will have an entry + created for it in the table. The 'val=bytes_req' parameter tells + the hist trigger that for each unique entry (call_site) in the + table, it should keep a running total of the number of bytes + requested by that call_site. + + We'll let it run for awhile and then dump the contents of the 'hist' + file in the kmalloc event's subdirectory (for readability, a number + of entries have been omitted): + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active] + + { call_site: 18446744072106379007 } hitcount: 1 bytes_req: 176 + { call_site: 18446744071579557049 } hitcount: 1 bytes_req: 1024 + { call_site: 18446744071580608289 } hitcount: 1 bytes_req: 16384 + { call_site: 18446744071581827654 } hitcount: 1 bytes_req: 24 + { call_site: 18446744071580700980 } hitcount: 1 bytes_req: 8 + { call_site: 18446744071579359876 } hitcount: 1 bytes_req: 152 + { call_site: 18446744071580795365 } hitcount: 3 bytes_req: 144 + { call_site: 18446744071581303129 } hitcount: 3 bytes_req: 144 + { call_site: 18446744071580713234 } hitcount: 4 bytes_req: 2560 + { call_site: 18446744071580933750 } hitcount: 4 bytes_req: 736 + . + . + . + { call_site: 18446744072106047046 } hitcount: 69 bytes_req: 5576 + { call_site: 18446744071582116407 } hitcount: 73 bytes_req: 2336 + { call_site: 18446744072106054684 } hitcount: 136 bytes_req: 140504 + { call_site: 18446744072106224230 } hitcount: 136 bytes_req: 19584 + { call_site: 18446744072106078074 } hitcount: 153 bytes_req: 2448 + { call_site: 18446744072106062406 } hitcount: 153 bytes_req: 36720 + { call_site: 18446744071582507929 } hitcount: 153 bytes_req: 37088 + { call_site: 18446744072102520590 } hitcount: 273 bytes_req: 10920 + { call_site: 18446744071582143559 } hitcount: 358 bytes_req: 716 + { call_site: 18446744072106465852 } hitcount: 417 bytes_req: 56712 + { call_site: 18446744072102523378 } hitcount: 485 bytes_req: 27160 + { call_site: 18446744072099568646 } hitcount: 1676 bytes_req: 33520 + + Totals: + Hits: 4610 + Entries: 45 + Dropped: 0 + + The output displays a line for each entry, beginning with the key + specified in the trigger, followed by the value(s) also specified in + the trigger. At the beginning of the output is a line that displays + the trigger info, which can also be displayed by reading the + 'trigger' file: + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + hist:keys=call_site:vals=bytes_req:sort=hitcount:size=2048 [active] + + At the end of the output are a few lines that display the overall + totals for the run. The 'Hits' field shows the total number of + times the event trigger was hit, the 'Entries' field shows the total + number of used entries in the hash table, and the 'Dropped' field + shows the number of hits that were dropped because the number of + used entries for the run exceeded the maximum number of entries + allowed for the table (normally 0, but if not a hint that you may + want to increase the size of the table using the 'size' parameter). + + Notice in the above output that there's an extra field, 'hitcount', + which wasn't specified in the trigger. Also notice that in the + trigger info output, there's a parameter, 'sort=hitcount', which + wasn't specified in the trigger either. The reason for that is that + every trigger implicitly keeps a count of the total number of hits + attributed to a given entry, called the 'hitcount'. That hitcount + information is explicitly displayed in the output, and in the + absence of a user-specified sort parameter, is used as the default + sort field. + + The value 'hitcount' can be used in place of an explicit value in + the 'values' parameter if you don't really need to have any + particular field summed and are mainly interested in hit + frequencies. + + To turn the hist trigger off, simply call up the trigger in the + command history and re-execute it with a '!' prepended: + + # echo '!hist:key=call_site:val=bytes_req' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + Finally, notice that the call_site as displayed in the output above + isn't really very useful. It's an address, but normally addresses + are displayed in hex. To have a numeric field displayed as a hex + value, simply append '.hex' to the field name in the trigger: + + # echo 'hist:key=call_site.hex:val=bytes_req' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=call_site.hex:vals=bytes_req:sort=hitcount:size=2048 [active] + + { call_site: ffffffffa026b291 } hitcount: 1 bytes_req: 433 + { call_site: ffffffffa07186ff } hitcount: 1 bytes_req: 176 + { call_site: ffffffff811ae721 } hitcount: 1 bytes_req: 16384 + { call_site: ffffffff811c5134 } hitcount: 1 bytes_req: 8 + { call_site: ffffffffa04a9ebb } hitcount: 1 bytes_req: 511 + { call_site: ffffffff8122e0a6 } hitcount: 1 bytes_req: 12 + { call_site: ffffffff8107da84 } hitcount: 1 bytes_req: 152 + { call_site: ffffffff812d8246 } hitcount: 1 bytes_req: 24 + { call_site: ffffffff811dc1e5 } hitcount: 3 bytes_req: 144 + { call_site: ffffffffa02515e8 } hitcount: 3 bytes_req: 648 + { call_site: ffffffff81258159 } hitcount: 3 bytes_req: 144 + { call_site: ffffffff811c80f4 } hitcount: 4 bytes_req: 544 + . + . + . + { call_site: ffffffffa06c7646 } hitcount: 106 bytes_req: 8024 + { call_site: ffffffffa06cb246 } hitcount: 132 bytes_req: 31680 + { call_site: ffffffffa06cef7a } hitcount: 132 bytes_req: 2112 + { call_site: ffffffff8137e399 } hitcount: 132 bytes_req: 23232 + { call_site: ffffffffa06c941c } hitcount: 185 bytes_req: 171360 + { call_site: ffffffffa06f2a66 } hitcount: 185 bytes_req: 26640 + { call_site: ffffffffa036a70e } hitcount: 265 bytes_req: 10600 + { call_site: ffffffff81325447 } hitcount: 292 bytes_req: 584 + { call_site: ffffffffa072da3c } hitcount: 446 bytes_req: 60656 + { call_site: ffffffffa036b1f2 } hitcount: 526 bytes_req: 29456 + { call_site: ffffffffa0099c06 } hitcount: 1780 bytes_req: 35600 + + Totals: + Hits: 4775 + Entries: 46 + Dropped: 0 + + Even that's only marginally more useful - while hex values do look + more like addresses, what users are typically more interested in + when looking at text addresses are the corresponding symbols + instead. To have an address displayed as symbolic value instead, + simply append '.sym' or '.sym-offset' to the field name in the + trigger: + + # echo 'hist:key=call_site.sym:val=bytes_req' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=hitcount:size=2048 [active] + + { call_site: [ffffffff810adcb9] syslog_print_all } hitcount: 1 bytes_req: 1024 + { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 + { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 + { call_site: [ffffffff8154acbe] usb_alloc_urb } hitcount: 1 bytes_req: 192 + { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 + { call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40 + { call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 + { call_site: [ffffffff811febd5] fsnotify_alloc_group } hitcount: 2 bytes_req: 528 + { call_site: [ffffffff81440f58] __tty_buffer_request_room } hitcount: 2 bytes_req: 2624 + { call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 2 bytes_req: 96 + { call_site: [ffffffffa05e19af] ieee80211_start_tx_ba_session [mac80211] } hitcount: 2 bytes_req: 464 + { call_site: [ffffffff81672406] tcp_get_metrics } hitcount: 2 bytes_req: 304 + { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 + { call_site: [ffffffff81089b05] sched_create_group } hitcount: 2 bytes_req: 1424 + . + . + . + { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1185 bytes_req: 123240 + { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 1185 bytes_req: 104280 + { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 1402 bytes_req: 190672 + { call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 1518 bytes_req: 146208 + { call_site: [ffffffffa029070e] drm_vma_node_allow [drm] } hitcount: 1746 bytes_req: 69840 + { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 2021 bytes_req: 792312 + { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 2592 bytes_req: 145152 + { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2629 bytes_req: 378576 + { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2629 bytes_req: 3783248 + { call_site: [ffffffff81325607] apparmor_file_alloc_security } hitcount: 5192 bytes_req: 10384 + { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 5529 bytes_req: 110584 + { call_site: [ffffffff8131ebf7] aa_alloc_task_context } hitcount: 21943 bytes_req: 702176 + { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 55759 bytes_req: 5074265 + + Totals: + Hits: 109928 + Entries: 71 + Dropped: 0 + + Because the default sort key above is 'hitcount', the above shows a + the list of call_sites by increasing hitcount, so that at the bottom + we see the functions that made the most kmalloc calls during the + run. If instead we we wanted to see the top kmalloc callers in + terms of the number of bytes requested rather than the number of + calls, and we wanted the top caller to appear at the top, we can use + the 'sort' parameter, along with the 'descending' modifier: + + # echo 'hist:key=call_site.sym:val=bytes_req:sort=bytes_req.descending' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=call_site.sym:vals=bytes_req:sort=bytes_req.descending:size=2048 [active] + + { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 2186 bytes_req: 3397464 + { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1790 bytes_req: 712176 + { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 8132 bytes_req: 513135 + { call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 106 bytes_req: 440128 + { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 2186 bytes_req: 314784 + { call_site: [ffffffff812891ca] ext4_find_extent } hitcount: 2174 bytes_req: 208992 + { call_site: [ffffffff811ae8e1] __kmalloc } hitcount: 8 bytes_req: 131072 + { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 859 bytes_req: 116824 + { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 1834 bytes_req: 102704 + { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 972 bytes_req: 101088 + { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl [drm] } hitcount: 972 bytes_req: 85536 + { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 3333 bytes_req: 66664 + { call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 209 bytes_req: 61632 + . + . + . + { call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 + { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 + { call_site: [ffffffff812d8406] copy_semundo } hitcount: 2 bytes_req: 48 + { call_site: [ffffffff81200ba6] inotify_new_group } hitcount: 1 bytes_req: 48 + { call_site: [ffffffffa027121a] drm_getmagic [drm] } hitcount: 1 bytes_req: 48 + { call_site: [ffffffff811e3a25] __seq_open_private } hitcount: 1 bytes_req: 40 + { call_site: [ffffffff811c52f4] bprm_change_interp } hitcount: 2 bytes_req: 16 + { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 + { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 + { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 + + Totals: + Hits: 32133 + Entries: 81 + Dropped: 0 + + To display the offset and size information in addition to the symbol + name, just use 'sym-offset' instead: + + # echo 'hist:key=call_site.sym-offset:val=bytes_req:sort=bytes_req.descending' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=call_site.sym-offset:vals=bytes_req:sort=bytes_req.descending:size=2048 [active] + + { call_site: [ffffffffa046041c] i915_gem_execbuffer2+0x6c/0x2c0 [i915] } hitcount: 4569 bytes_req: 3163720 + { call_site: [ffffffffa0489a66] intel_ring_begin+0xc6/0x1f0 [i915] } hitcount: 4569 bytes_req: 657936 + { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23+0x694/0x1020 [i915] } hitcount: 1519 bytes_req: 472936 + { call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23+0x516/0x1020 [i915] } hitcount: 3050 bytes_req: 211832 + { call_site: [ffffffff811e2a1b] seq_buf_alloc+0x1b/0x50 } hitcount: 34 bytes_req: 148384 + { call_site: [ffffffffa04a580c] intel_crtc_page_flip+0xbc/0x870 [i915] } hitcount: 1385 bytes_req: 144040 + { call_site: [ffffffff811ae8e1] __kmalloc+0x191/0x1b0 } hitcount: 8 bytes_req: 131072 + { call_site: [ffffffffa0287592] drm_mode_page_flip_ioctl+0x282/0x360 [drm] } hitcount: 1385 bytes_req: 121880 + { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc+0x32/0x100 [drm] } hitcount: 1848 bytes_req: 103488 + { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state+0x2c/0xa0 [i915] } hitcount: 461 bytes_req: 62696 + { call_site: [ffffffffa029070e] drm_vma_node_allow+0x2e/0xd0 [drm] } hitcount: 1541 bytes_req: 61640 + { call_site: [ffffffff815f8d7b] sk_prot_alloc+0xcb/0x1b0 } hitcount: 57 bytes_req: 57456 + . + . + . + { call_site: [ffffffff8109524a] alloc_fair_sched_group+0x5a/0x1a0 } hitcount: 2 bytes_req: 128 + { call_site: [ffffffffa027b921] drm_vm_open_locked+0x31/0xa0 [drm] } hitcount: 3 bytes_req: 96 + { call_site: [ffffffff8122e266] proc_self_follow_link+0x76/0xb0 } hitcount: 8 bytes_req: 96 + { call_site: [ffffffff81213e80] load_elf_binary+0x240/0x1650 } hitcount: 3 bytes_req: 84 + { call_site: [ffffffff8154bc62] usb_control_msg+0x42/0x110 } hitcount: 1 bytes_req: 8 + { call_site: [ffffffffa00bf6fe] hidraw_send_report+0x7e/0x1a0 [hid] } hitcount: 1 bytes_req: 7 + { call_site: [ffffffffa00bf1ca] hidraw_report_event+0x8a/0x120 [hid] } hitcount: 1 bytes_req: 7 + + Totals: + Hits: 26098 + Entries: 64 + Dropped: 0 + + We can also add multiple fields to the 'values' parameter. For + example, we might want to see the total number of bytes allocated + alongside bytes requested, and display the result sorted by bytes + allocated in a descending order: + + # echo 'hist:keys=call_site.sym:values=bytes_req,bytes_alloc:sort=bytes_alloc.descending' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=call_site.sym:vals=bytes_req,bytes_alloc:sort=bytes_alloc.descending:size=2048 [active] + + { call_site: [ffffffffa046041c] i915_gem_execbuffer2 [i915] } hitcount: 7403 bytes_req: 4084360 bytes_alloc: 5958016 + { call_site: [ffffffff811e2a1b] seq_buf_alloc } hitcount: 541 bytes_req: 2213968 bytes_alloc: 2228224 + { call_site: [ffffffffa0489a66] intel_ring_begin [i915] } hitcount: 7404 bytes_req: 1066176 bytes_alloc: 1421568 + { call_site: [ffffffffa045e7c4] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 1565 bytes_req: 557368 bytes_alloc: 1037760 + { call_site: [ffffffff8125847d] ext4_htree_store_dirent } hitcount: 9557 bytes_req: 595778 bytes_alloc: 695744 + { call_site: [ffffffffa045e646] i915_gem_do_execbuffer.isra.23 [i915] } hitcount: 5839 bytes_req: 430680 bytes_alloc: 470400 + { call_site: [ffffffffa04c4a3c] intel_plane_duplicate_state [i915] } hitcount: 2388 bytes_req: 324768 bytes_alloc: 458496 + { call_site: [ffffffffa02911f2] drm_modeset_lock_crtc [drm] } hitcount: 3911 bytes_req: 219016 bytes_alloc: 250304 + { call_site: [ffffffff815f8d7b] sk_prot_alloc } hitcount: 235 bytes_req: 236880 bytes_alloc: 240640 + { call_site: [ffffffff8137e559] sg_kmalloc } hitcount: 557 bytes_req: 169024 bytes_alloc: 221760 + { call_site: [ffffffffa00b7c06] hid_report_raw_event [hid] } hitcount: 9378 bytes_req: 187548 bytes_alloc: 206312 + { call_site: [ffffffffa04a580c] intel_crtc_page_flip [i915] } hitcount: 1519 bytes_req: 157976 bytes_alloc: 194432 + . + . + . + { call_site: [ffffffff8109bd3b] sched_autogroup_create_attach } hitcount: 2 bytes_req: 144 bytes_alloc: 192 + { call_site: [ffffffff81097ee8] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 + { call_site: [ffffffff8109524a] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 + { call_site: [ffffffff81095225] alloc_fair_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 + { call_site: [ffffffff81097ec2] alloc_rt_sched_group } hitcount: 2 bytes_req: 128 bytes_alloc: 128 + { call_site: [ffffffff81213e80] load_elf_binary } hitcount: 3 bytes_req: 84 bytes_alloc: 96 + { call_site: [ffffffff81079a2e] kthread_create_on_node } hitcount: 1 bytes_req: 56 bytes_alloc: 64 + { call_site: [ffffffffa00bf6fe] hidraw_send_report [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8 + { call_site: [ffffffff8154bc62] usb_control_msg } hitcount: 1 bytes_req: 8 bytes_alloc: 8 + { call_site: [ffffffffa00bf1ca] hidraw_report_event [hid] } hitcount: 1 bytes_req: 7 bytes_alloc: 8 + + Totals: + Hits: 66598 + Entries: 65 + Dropped: 0 + + Finally, to finish off our kmalloc example, instead of simply having + the hist trigger display symbolic call_sites, we can have the hist + trigger additionally display the complete set of kernel stack traces + that led to each call_site. To do that, we simply use the special + value 'stacktrace' for the key parameter: + + # echo 'hist:keys=stacktrace:values=bytes_req,bytes_alloc:sort=bytes_alloc' > \ + /sys/kernel/debug/tracing/events/kmem/kmalloc/trigger + + The above trigger will use the kernel stack trace in effect when an + event is triggered as the key for the hash table. This allows the + enumeration of every kernel callpath that led up to a particular + event, along with a running total of any of the event fields for + that event. Here we tally bytes requested and bytes allocated for + every callpath in the system that led up to a kmalloc (in this case + every callpath to a kmalloc for a kernel compile): + + # cat /sys/kernel/debug/tracing/events/kmem/kmalloc/hist + # trigger info: hist:keys=stacktrace:vals=bytes_req,bytes_alloc:sort=bytes_alloc:size=2048 [active] + + { stacktrace: + __kmalloc_track_caller+0x10b/0x1a0 + kmemdup+0x20/0x50 + hidraw_report_event+0x8a/0x120 [hid] + hid_report_raw_event+0x3ea/0x440 [hid] + hid_input_report+0x112/0x190 [hid] + hid_irq_in+0xc2/0x260 [usbhid] + __usb_hcd_giveback_urb+0x72/0x120 + usb_giveback_urb_bh+0x9e/0xe0 + tasklet_hi_action+0xf8/0x100 + __do_softirq+0x114/0x2c0 + irq_exit+0xa5/0xb0 + do_IRQ+0x5a/0xf0 + ret_from_intr+0x0/0x30 + cpuidle_enter+0x17/0x20 + cpu_startup_entry+0x315/0x3e0 + rest_init+0x7c/0x80 + } hitcount: 3 bytes_req: 21 bytes_alloc: 24 + { stacktrace: + __kmalloc_track_caller+0x10b/0x1a0 + kmemdup+0x20/0x50 + hidraw_report_event+0x8a/0x120 [hid] + hid_report_raw_event+0x3ea/0x440 [hid] + hid_input_report+0x112/0x190 [hid] + hid_irq_in+0xc2/0x260 [usbhid] + __usb_hcd_giveback_urb+0x72/0x120 + usb_giveback_urb_bh+0x9e/0xe0 + tasklet_hi_action+0xf8/0x100 + __do_softirq+0x114/0x2c0 + irq_exit+0xa5/0xb0 + do_IRQ+0x5a/0xf0 + ret_from_intr+0x0/0x30 + } hitcount: 3 bytes_req: 21 bytes_alloc: 24 + { stacktrace: + kmem_cache_alloc_trace+0xeb/0x150 + aa_alloc_task_context+0x27/0x40 + apparmor_cred_prepare+0x1f/0x50 + security_prepare_creds+0x16/0x20 + prepare_creds+0xdf/0x1a0 + SyS_capset+0xb5/0x200 + system_call_fastpath+0x12/0x6a + } hitcount: 1 bytes_req: 32 bytes_alloc: 32 + . + . + . + { stacktrace: + __kmalloc+0x11b/0x1b0 + i915_gem_execbuffer2+0x6c/0x2c0 [i915] + drm_ioctl+0x349/0x670 [drm] + do_vfs_ioctl+0x2f0/0x4f0 + SyS_ioctl+0x81/0xa0 + system_call_fastpath+0x12/0x6a + } hitcount: 17726 bytes_req: 13944120 bytes_alloc: 19593808 + { stacktrace: + __kmalloc+0x11b/0x1b0 + load_elf_phdrs+0x76/0xa0 + load_elf_binary+0x102/0x1650 + search_binary_handler+0x97/0x1d0 + do_execveat_common.isra.34+0x551/0x6e0 + SyS_execve+0x3a/0x50 + return_from_execve+0x0/0x23 + } hitcount: 33348 bytes_req: 17152128 bytes_alloc: 20226048 + { stacktrace: + kmem_cache_alloc_trace+0xeb/0x150 + apparmor_file_alloc_security+0x27/0x40 + security_file_alloc+0x16/0x20 + get_empty_filp+0x93/0x1c0 + path_openat+0x31/0x5f0 + do_filp_open+0x3a/0x90 + do_sys_open+0x128/0x220 + SyS_open+0x1e/0x20 + system_call_fastpath+0x12/0x6a + } hitcount: 4766422 bytes_req: 9532844 bytes_alloc: 38131376 + { stacktrace: + __kmalloc+0x11b/0x1b0 + seq_buf_alloc+0x1b/0x50 + seq_read+0x2cc/0x370 + proc_reg_read+0x3d/0x80 + __vfs_read+0x28/0xe0 + vfs_read+0x86/0x140 + SyS_read+0x46/0xb0 + system_call_fastpath+0x12/0x6a + } hitcount: 19133 bytes_req: 78368768 bytes_alloc: 78368768 + + Totals: + Hits: 6085872 + Entries: 253 + Dropped: 0 + + If you key a hist trigger on common_pid, in order for example to + gather and display sorted totals for each process, you can use the + special .execname modifier to display the executable names for the + processes in the table rather than raw pids. The example below + keeps a per-process sum of total bytes read: + + # echo 'hist:key=common_pid.execname:val=count:sort=count.descending' > \ + /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/trigger + + # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_read/hist + # trigger info: hist:keys=common_pid.execname:vals=count:sort=count.descending:size=2048 [active] + + { common_pid: gnome-terminal [ 3196] } hitcount: 280 count: 1093512 + { common_pid: Xorg [ 1309] } hitcount: 525 count: 256640 + { common_pid: compiz [ 2889] } hitcount: 59 count: 254400 + { common_pid: bash [ 8710] } hitcount: 3 count: 66369 + { common_pid: dbus-daemon-lau [ 8703] } hitcount: 49 count: 47739 + { common_pid: irqbalance [ 1252] } hitcount: 27 count: 27648 + { common_pid: 01ifupdown [ 8705] } hitcount: 3 count: 17216 + { common_pid: dbus-daemon [ 772] } hitcount: 10 count: 12396 + { common_pid: Socket Thread [ 8342] } hitcount: 11 count: 11264 + { common_pid: nm-dhcp-client. [ 8701] } hitcount: 6 count: 7424 + { common_pid: gmain [ 1315] } hitcount: 18 count: 6336 + . + . + . + { common_pid: postgres [ 1892] } hitcount: 2 count: 32 + { common_pid: postgres [ 1891] } hitcount: 2 count: 32 + { common_pid: gmain [ 8704] } hitcount: 2 count: 32 + { common_pid: upstart-dbus-br [ 2740] } hitcount: 21 count: 21 + { common_pid: nm-dispatcher.a [ 8696] } hitcount: 1 count: 16 + { common_pid: indicator-datet [ 2904] } hitcount: 1 count: 16 + { common_pid: gdbus [ 2998] } hitcount: 1 count: 16 + { common_pid: rtkit-daemon [ 2052] } hitcount: 1 count: 8 + { common_pid: init [ 1] } hitcount: 2 count: 2 + + Totals: + Hits: 2116 + Entries: 51 + Dropped: 0 + + Similarly, if you key a hist trigger on syscall id, for example to + gather and display a list of systemwide syscall hits, you can use + the special .syscall modifier to display the syscall names rather + than raw ids. The example below keeps a running total of syscall + counts for the system during the run: + + # echo 'hist:key=id.syscall:val=hitcount' > \ + /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger + + # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist + # trigger info: hist:keys=id.syscall:vals=hitcount:sort=hitcount:size=2048 [active] + + { id: sys_fsync [ 74] } hitcount: 1 + { id: sys_newuname [ 63] } hitcount: 1 + { id: sys_prctl [157] } hitcount: 1 + { id: sys_statfs [137] } hitcount: 1 + { id: sys_symlink [ 88] } hitcount: 1 + { id: sys_sendmmsg [307] } hitcount: 1 + { id: sys_semctl [ 66] } hitcount: 1 + { id: sys_readlink [ 89] } hitcount: 3 + { id: sys_bind [ 49] } hitcount: 3 + { id: sys_getsockname [ 51] } hitcount: 3 + { id: sys_unlink [ 87] } hitcount: 3 + { id: sys_rename [ 82] } hitcount: 4 + { id: unknown_syscall [ 58] } hitcount: 4 + { id: sys_connect [ 42] } hitcount: 4 + { id: sys_getpid [ 39] } hitcount: 4 + . + . + . + { id: sys_rt_sigprocmask [ 14] } hitcount: 952 + { id: sys_futex [202] } hitcount: 1534 + { id: sys_write [ 1] } hitcount: 2689 + { id: sys_setitimer [ 38] } hitcount: 2797 + { id: sys_read [ 0] } hitcount: 3202 + { id: sys_select [ 23] } hitcount: 3773 + { id: sys_writev [ 20] } hitcount: 4531 + { id: sys_poll [ 7] } hitcount: 8314 + { id: sys_recvmsg [ 47] } hitcount: 13738 + { id: sys_ioctl [ 16] } hitcount: 21843 + + Totals: + Hits: 67612 + Entries: 72 + Dropped: 0 + + The syscall counts above provide a rough overall picture of system + call activity on the system; we can see for example that the most + popular system call on this system was the 'sys_ioctl' system call. + + We can use 'compound' keys to refine that number and provide some + further insight as to which processes exactly contribute to the + overall ioctl count. + + The command below keeps a hitcount for every unique combination of + system call id and pid - the end result is essentially a table + that keeps a per-pid sum of system call hits. The results are + sorted using the system call id as the primary key, and the + hitcount sum as the secondary key: + + # echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount' > \ + /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger + + # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist + # trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 [active] + + { id: sys_read [ 0], common_pid: rtkit-daemon [ 1877] } hitcount: 1 + { id: sys_read [ 0], common_pid: gdbus [ 2976] } hitcount: 1 + { id: sys_read [ 0], common_pid: console-kit-dae [ 3400] } hitcount: 1 + { id: sys_read [ 0], common_pid: postgres [ 1865] } hitcount: 1 + { id: sys_read [ 0], common_pid: deja-dup-monito [ 3543] } hitcount: 2 + { id: sys_read [ 0], common_pid: NetworkManager [ 890] } hitcount: 2 + { id: sys_read [ 0], common_pid: evolution-calen [ 3048] } hitcount: 2 + { id: sys_read [ 0], common_pid: postgres [ 1864] } hitcount: 2 + { id: sys_read [ 0], common_pid: nm-applet [ 3022] } hitcount: 2 + { id: sys_read [ 0], common_pid: whoopsie [ 1212] } hitcount: 2 + . + . + . + { id: sys_ioctl [ 16], common_pid: bash [ 8479] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: bash [ 3472] } hitcount: 12 + { id: sys_ioctl [ 16], common_pid: gnome-terminal [ 3199] } hitcount: 16 + { id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 1808 + { id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 5580 + . + . + . + { id: sys_waitid [247], common_pid: upstart-dbus-br [ 2690] } hitcount: 3 + { id: sys_waitid [247], common_pid: upstart-dbus-br [ 2688] } hitcount: 16 + { id: sys_inotify_add_watch [254], common_pid: gmain [ 975] } hitcount: 2 + { id: sys_inotify_add_watch [254], common_pid: gmain [ 3204] } hitcount: 4 + { id: sys_inotify_add_watch [254], common_pid: gmain [ 2888] } hitcount: 4 + { id: sys_inotify_add_watch [254], common_pid: gmain [ 3003] } hitcount: 4 + { id: sys_inotify_add_watch [254], common_pid: gmain [ 2873] } hitcount: 4 + { id: sys_inotify_add_watch [254], common_pid: gmain [ 3196] } hitcount: 6 + { id: sys_openat [257], common_pid: java [ 2623] } hitcount: 2 + { id: sys_eventfd2 [290], common_pid: ibus-ui-gtk3 [ 2760] } hitcount: 4 + { id: sys_eventfd2 [290], common_pid: compiz [ 2994] } hitcount: 6 + + Totals: + Hits: 31536 + Entries: 323 + Dropped: 0 + + The above list does give us a breakdown of the ioctl syscall by + pid, but it also gives us quite a bit more than that, which we + don't really care about at the moment. Since we know the syscall + id for sys_ioctl (16, displayed next to the sys_ioctl name), we + can use that to filter out all the other syscalls: + + # echo 'hist:key=id.syscall,common_pid.execname:val=hitcount:sort=id,hitcount if id == 16' > \ + /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/trigger + + # cat /sys/kernel/debug/tracing/events/raw_syscalls/sys_enter/hist + # trigger info: hist:keys=id.syscall,common_pid.execname:vals=hitcount:sort=id.syscall,hitcount:size=2048 if id == 16 [active] + + { id: sys_ioctl [ 16], common_pid: gmain [ 2769] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: evolution-addre [ 8571] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: gmain [ 3003] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: gmain [ 2781] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: gmain [ 2829] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: bash [ 8726] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: bash [ 8508] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: gmain [ 2970] } hitcount: 1 + { id: sys_ioctl [ 16], common_pid: gmain [ 2768] } hitcount: 1 + . + . + . + { id: sys_ioctl [ 16], common_pid: pool [ 8559] } hitcount: 45 + { id: sys_ioctl [ 16], common_pid: pool [ 8555] } hitcount: 48 + { id: sys_ioctl [ 16], common_pid: pool [ 8551] } hitcount: 48 + { id: sys_ioctl [ 16], common_pid: avahi-daemon [ 896] } hitcount: 66 + { id: sys_ioctl [ 16], common_pid: Xorg [ 1267] } hitcount: 26674 + { id: sys_ioctl [ 16], common_pid: compiz [ 2994] } hitcount: 73443 + + Totals: + Hits: 101162 + Entries: 103 + Dropped: 0 + + The above output shows that 'compiz' and 'Xorg' are far and away + the heaviest ioctl callers (which might lead to questions about + whether they really need to be making all those calls and to + possible avenues for further investigation.) + + The compound key examples used a key and a sum value (hitcount) to + sort the output, but we can just as easily use two keys instead. + Here's an example where we use a compound key composed of the the + common_pid and size event fields. Sorting with pid as the primary + key and 'size' as the secondary key allows us to display an + ordered summary of the recvfrom sizes, with counts, received by + each process: + + # echo 'hist:key=common_pid.execname,size:val=hitcount:sort=common_pid,size' > \ + /sys/kernel/debug/tracing/events/syscalls/sys_enter_recvfrom/trigger + + # cat /sys/kernel/debug/tracing/events/syscalls/sys_enter_recvfrom/hist + # trigger info: hist:keys=common_pid.execname,size:vals=hitcount:sort=common_pid.execname,size:size=2048 [active] + + { common_pid: smbd [ 784], size: 4 } hitcount: 1 + { common_pid: dnsmasq [ 1412], size: 4096 } hitcount: 672 + { common_pid: postgres [ 1796], size: 1000 } hitcount: 6 + { common_pid: postgres [ 1867], size: 1000 } hitcount: 10 + { common_pid: bamfdaemon [ 2787], size: 28 } hitcount: 2 + { common_pid: bamfdaemon [ 2787], size: 14360 } hitcount: 1 + { common_pid: compiz [ 2994], size: 8 } hitcount: 1 + { common_pid: compiz [ 2994], size: 20 } hitcount: 11 + { common_pid: gnome-terminal [ 3199], size: 4 } hitcount: 2 + { common_pid: firefox [ 8817], size: 4 } hitcount: 1 + { common_pid: firefox [ 8817], size: 8 } hitcount: 5 + { common_pid: firefox [ 8817], size: 588 } hitcount: 2 + { common_pid: firefox [ 8817], size: 628 } hitcount: 1 + { common_pid: firefox [ 8817], size: 6944 } hitcount: 1 + { common_pid: firefox [ 8817], size: 408880 } hitcount: 2 + { common_pid: firefox [ 8822], size: 8 } hitcount: 2 + { common_pid: firefox [ 8822], size: 160 } hitcount: 2 + { common_pid: firefox [ 8822], size: 320 } hitcount: 2 + { common_pid: firefox [ 8822], size: 352 } hitcount: 1 + . + . + . + { common_pid: pool [ 8923], size: 1960 } hitcount: 10 + { common_pid: pool [ 8923], size: 2048 } hitcount: 10 + { common_pid: pool [ 8924], size: 1960 } hitcount: 10 + { common_pid: pool [ 8924], size: 2048 } hitcount: 10 + { common_pid: pool [ 8928], size: 1964 } hitcount: 4 + { common_pid: pool [ 8928], size: 1965 } hitcount: 2 + { common_pid: pool [ 8928], size: 2048 } hitcount: 6 + { common_pid: pool [ 8929], size: 1982 } hitcount: 1 + { common_pid: pool [ 8929], size: 2048 } hitcount: 1 + + Totals: + Hits: 2016 + Entries: 224 + Dropped: 0 + + The above example also illustrates the fact that although a compound + key is treated as a single entity for hashing purposes, the sub-keys + it's composed of can be accessed independently. + + The next example uses a string field as the hash key and + demonstrates how you can manually pause and continue a hist trigger. + In this example, we'll aggregate fork counts and don't expect a + large number of entries in the hash table, so we'll drop it to a + much smaller number, say 256: + + # echo 'hist:key=child_comm:val=hitcount:size=256' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger + + # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist + # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active] + + { child_comm: dconf worker } hitcount: 1 + { child_comm: ibus-daemon } hitcount: 1 + { child_comm: whoopsie } hitcount: 1 + { child_comm: smbd } hitcount: 1 + { child_comm: gdbus } hitcount: 1 + { child_comm: kthreadd } hitcount: 1 + { child_comm: dconf worker } hitcount: 1 + { child_comm: evolution-alarm } hitcount: 2 + { child_comm: Socket Thread } hitcount: 2 + { child_comm: postgres } hitcount: 2 + { child_comm: bash } hitcount: 3 + { child_comm: compiz } hitcount: 3 + { child_comm: evolution-sourc } hitcount: 4 + { child_comm: dhclient } hitcount: 4 + { child_comm: pool } hitcount: 5 + { child_comm: nm-dispatcher.a } hitcount: 8 + { child_comm: firefox } hitcount: 8 + { child_comm: dbus-daemon } hitcount: 8 + { child_comm: glib-pacrunner } hitcount: 10 + { child_comm: evolution } hitcount: 23 + + Totals: + Hits: 89 + Entries: 20 + Dropped: 0 + + If we want to pause the hist trigger, we can simply append :pause to + the command that started the trigger. Notice that the trigger info + displays as [paused]: + + # echo 'hist:key=child_comm:val=hitcount:size=256:pause' >> \ + /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger + + # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist + # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [paused] + + { child_comm: dconf worker } hitcount: 1 + { child_comm: kthreadd } hitcount: 1 + { child_comm: dconf worker } hitcount: 1 + { child_comm: gdbus } hitcount: 1 + { child_comm: ibus-daemon } hitcount: 1 + { child_comm: Socket Thread } hitcount: 2 + { child_comm: evolution-alarm } hitcount: 2 + { child_comm: smbd } hitcount: 2 + { child_comm: bash } hitcount: 3 + { child_comm: whoopsie } hitcount: 3 + { child_comm: compiz } hitcount: 3 + { child_comm: evolution-sourc } hitcount: 4 + { child_comm: pool } hitcount: 5 + { child_comm: postgres } hitcount: 6 + { child_comm: firefox } hitcount: 8 + { child_comm: dhclient } hitcount: 10 + { child_comm: emacs } hitcount: 12 + { child_comm: dbus-daemon } hitcount: 20 + { child_comm: nm-dispatcher.a } hitcount: 20 + { child_comm: evolution } hitcount: 35 + { child_comm: glib-pacrunner } hitcount: 59 + + Totals: + Hits: 199 + Entries: 21 + Dropped: 0 + + To manually continue having the trigger aggregate events, append + :cont instead. Notice that the trigger info displays as [active] + again, and the data has changed: + + # echo 'hist:key=child_comm:val=hitcount:size=256:cont' >> \ + /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger + + # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist + # trigger info: hist:keys=child_comm:vals=hitcount:sort=hitcount:size=256 [active] + + { child_comm: dconf worker } hitcount: 1 + { child_comm: dconf worker } hitcount: 1 + { child_comm: kthreadd } hitcount: 1 + { child_comm: gdbus } hitcount: 1 + { child_comm: ibus-daemon } hitcount: 1 + { child_comm: Socket Thread } hitcount: 2 + { child_comm: evolution-alarm } hitcount: 2 + { child_comm: smbd } hitcount: 2 + { child_comm: whoopsie } hitcount: 3 + { child_comm: compiz } hitcount: 3 + { child_comm: evolution-sourc } hitcount: 4 + { child_comm: bash } hitcount: 5 + { child_comm: pool } hitcount: 5 + { child_comm: postgres } hitcount: 6 + { child_comm: firefox } hitcount: 8 + { child_comm: dhclient } hitcount: 11 + { child_comm: emacs } hitcount: 12 + { child_comm: dbus-daemon } hitcount: 22 + { child_comm: nm-dispatcher.a } hitcount: 22 + { child_comm: evolution } hitcount: 35 + { child_comm: glib-pacrunner } hitcount: 59 + + Totals: + Hits: 206 + Entries: 21 + Dropped: 0 + + The previous example showed how to start and stop a hist trigger by + appending 'pause' and 'continue' to the hist trigger command. A + hist trigger can also be started in a paused state by initially + starting the trigger with ':pause' appended. This allows you to + start the trigger only when you're ready to start collecting data + and not before. For example, you could start the trigger in a + paused state, then unpause it and do something you want to measure, + then pause the trigger again when done. + + Of course, doing this manually can be difficult and error-prone, but + it is possible to automatically start and stop a hist trigger based + on some condition, via the enable_hist and disable_hist triggers. + + For example, suppose we wanted to take a look at the relative + weights in terms of skb length for each callpath that leads to a + netif_receieve_skb event when downloading a decent-sized file using + wget. + + First we set up an initially paused stacktrace trigger on the + netif_receive_skb event: + + # echo 'hist:key=stacktrace:vals=len:pause' > \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + + Next, we set up an 'enable_hist' trigger on the sched_process_exec + event, with an 'if filename==/usr/bin/wget' filter. The effect of + this new trigger is that it will 'unpause' the hist trigger we just + set up on netif_receive_skb if and only if it sees a + sched_process_exec event with a filename of '/usr/bin/wget'. When + that happens, all netif_receive_skb events are aggregated into a + hash table keyed on stacktrace: + + # echo 'enable_hist:net:netif_receive_skb if filename==/usr/bin/wget' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger + + The aggregation continues until the netif_receive_skb is paused + again, which is what the following disable_hist event does by + creating a similar setup on the sched_process_exit event, using the + filter 'comm==wget': + + # echo 'disable_hist:net:netif_receive_skb if comm==wget' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger + + Whenever a process exits and the comm field of the disable_hist + trigger filter matches 'comm==wget', the netif_receive_skb hist + trigger is disabled. + + The overall effect is that netif_receive_skb events are aggregated + into the hash table for only the duration of the wget. Executing a + wget command and then listing the 'hist' file will display the + output generated by the wget command: + + $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz + + # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist + # trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused] + + { stacktrace: + __netif_receive_skb_core+0x46d/0x990 + __netif_receive_skb+0x18/0x60 + netif_receive_skb_internal+0x23/0x90 + napi_gro_receive+0xc8/0x100 + ieee80211_deliver_skb+0xd6/0x270 [mac80211] + ieee80211_rx_handlers+0xccf/0x22f0 [mac80211] + ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211] + ieee80211_rx+0x31d/0x900 [mac80211] + iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm] + iwl_rx_dispatch+0x8e/0xf0 [iwldvm] + iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi] + irq_thread_fn+0x20/0x50 + irq_thread+0x11f/0x150 + kthread+0xd2/0xf0 + ret_from_fork+0x42/0x70 + } hitcount: 85 len: 28884 + { stacktrace: + __netif_receive_skb_core+0x46d/0x990 + __netif_receive_skb+0x18/0x60 + netif_receive_skb_internal+0x23/0x90 + napi_gro_complete+0xa4/0xe0 + dev_gro_receive+0x23a/0x360 + napi_gro_receive+0x30/0x100 + ieee80211_deliver_skb+0xd6/0x270 [mac80211] + ieee80211_rx_handlers+0xccf/0x22f0 [mac80211] + ieee80211_prepare_and_rx_handle+0x4e7/0xc40 [mac80211] + ieee80211_rx+0x31d/0x900 [mac80211] + iwlagn_rx_reply_rx+0x3db/0x6f0 [iwldvm] + iwl_rx_dispatch+0x8e/0xf0 [iwldvm] + iwl_pcie_irq_handler+0xe3c/0x12f0 [iwlwifi] + irq_thread_fn+0x20/0x50 + irq_thread+0x11f/0x150 + kthread+0xd2/0xf0 + } hitcount: 98 len: 664329 + { stacktrace: + __netif_receive_skb_core+0x46d/0x990 + __netif_receive_skb+0x18/0x60 + process_backlog+0xa8/0x150 + net_rx_action+0x15d/0x340 + __do_softirq+0x114/0x2c0 + do_softirq_own_stack+0x1c/0x30 + do_softirq+0x65/0x70 + __local_bh_enable_ip+0xb5/0xc0 + ip_finish_output+0x1f4/0x840 + ip_output+0x6b/0xc0 + ip_local_out_sk+0x31/0x40 + ip_send_skb+0x1a/0x50 + udp_send_skb+0x173/0x2a0 + udp_sendmsg+0x2bf/0x9f0 + inet_sendmsg+0x64/0xa0 + sock_sendmsg+0x3d/0x50 + } hitcount: 115 len: 13030 + { stacktrace: + __netif_receive_skb_core+0x46d/0x990 + __netif_receive_skb+0x18/0x60 + netif_receive_skb_internal+0x23/0x90 + napi_gro_complete+0xa4/0xe0 + napi_gro_flush+0x6d/0x90 + iwl_pcie_irq_handler+0x92a/0x12f0 [iwlwifi] + irq_thread_fn+0x20/0x50 + irq_thread+0x11f/0x150 + kthread+0xd2/0xf0 + ret_from_fork+0x42/0x70 + } hitcount: 934 len: 5512212 + + Totals: + Hits: 1232 + Entries: 4 + Dropped: 0 + + The above shows all the netif_receive_skb callpaths and their total + lengths for the duration of the wget command. + + The 'clear' hist trigger param can be used to clear the hash table. + Suppose we wanted to try another run of the previous example but + this time also wanted to see the complete list of events that went + into the histogram. In order to avoid having to set everything up + again, we can just clear the histogram first: + + # echo 'hist:key=stacktrace:vals=len:clear' >> \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + + Just to verify that it is in fact cleared, here's what we now see in + the hist file: + + # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist + # trigger info: hist:keys=stacktrace:vals=len:sort=hitcount:size=2048 [paused] + + Totals: + Hits: 0 + Entries: 0 + Dropped: 0 + + Since we want to see the detailed list of every netif_receive_skb + event occurring during the new run, which are in fact the same + events being aggregated into the hash table, we add some additional + 'enable_event' events to the triggering sched_process_exec and + sched_process_exit events as such: + + # echo 'enable_event:net:netif_receive_skb if filename==/usr/bin/wget' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger + + # echo 'disable_event:net:netif_receive_skb if comm==wget' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger + + If you read the trigger files for the sched_process_exec and + sched_process_exit triggers, you should see two triggers for each: + one enabling/disabling the hist aggregation and the other + enabling/disabling the logging of events: + + # cat /sys/kernel/debug/tracing/events/sched/sched_process_exec/trigger + enable_event:net:netif_receive_skb:unlimited if filename==/usr/bin/wget + enable_hist:net:netif_receive_skb:unlimited if filename==/usr/bin/wget + + # cat /sys/kernel/debug/tracing/events/sched/sched_process_exit/trigger + enable_event:net:netif_receive_skb:unlimited if comm==wget + disable_hist:net:netif_receive_skb:unlimited if comm==wget + + In other words, whenever either of the sched_process_exec or + sched_process_exit events is hit and matches 'wget', it enables or + disables both the histogram and the event log, and what you end up + with is a hash table and set of events just covering the specified + duration. Run the wget command again: + + $ wget https://www.kernel.org/pub/linux/kernel/v3.x/patch-3.19.xz + + Displaying the 'hist' file should show something similar to what you + saw in the last run, but this time you should also see the + individual events in the trace file: + + # cat /sys/kernel/debug/tracing/trace + + # tracer: nop + # + # entries-in-buffer/entries-written: 183/1426 #P:4 + # + # _-----=> irqs-off + # / _----=> need-resched + # | / _---=> hardirq/softirq + # || / _--=> preempt-depth + # ||| / delay + # TASK-PID CPU# |||| TIMESTAMP FUNCTION + # | | | |||| | | + wget-15108 [000] ..s1 31769.606929: netif_receive_skb: dev=lo skbaddr=ffff88009c353100 len=60 + wget-15108 [000] ..s1 31769.606999: netif_receive_skb: dev=lo skbaddr=ffff88009c353200 len=60 + dnsmasq-1382 [000] ..s1 31769.677652: netif_receive_skb: dev=lo skbaddr=ffff88009c352b00 len=130 + dnsmasq-1382 [000] ..s1 31769.685917: netif_receive_skb: dev=lo skbaddr=ffff88009c352200 len=138 + ##### CPU 2 buffer started #### + irq/29-iwlwifi-559 [002] ..s. 31772.031529: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433d00 len=2948 + irq/29-iwlwifi-559 [002] ..s. 31772.031572: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432200 len=1500 + irq/29-iwlwifi-559 [002] ..s. 31772.032196: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433100 len=2948 + irq/29-iwlwifi-559 [002] ..s. 31772.032761: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d433000 len=2948 + irq/29-iwlwifi-559 [002] ..s. 31772.033220: netif_receive_skb: dev=wlan0 skbaddr=ffff88009d432e00 len=1500 + . + . + . From 52a7f16dedff8f23d03df3ea556dec95b92a5801 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:57 -0600 Subject: [PATCH 23/45] tracing: Add support for multiple hist triggers per event Allow users to define any number of hist triggers per trace event. Any number of hist triggers may be added for a given event, which may differ by key, value, or filter. Reading the event's 'hist' file will display the output of all the hist triggers defined on an event concatenated in the order they were defined. Link: http://lkml.kernel.org/r/48a0c8dd34c344571de880fb35e211c6d9a28961.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- Documentation/trace/events.txt | 154 +++++++++++++++++++++++++-- kernel/trace/trace.c | 8 +- kernel/trace/trace_events_hist.c | 172 +++++++++++++++++++++++++------ 3 files changed, 293 insertions(+), 41 deletions(-) diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt index db223e85bd2f..cc0216760b78 100644 --- a/Documentation/trace/events.txt +++ b/Documentation/trace/events.txt @@ -550,12 +550,14 @@ The following commands are supported: 'hist' triggers add a 'hist' file to each event's subdirectory. Reading the 'hist' file for the event will dump the hash table in - its entirety to stdout. Each printed hash table entry is a simple - list of the keys and values comprising the entry; keys are printed - first and are delineated by curly braces, and are followed by the - set of value fields for the entry. By default, numeric fields are - displayed as base-10 integers. This can be modified by appending - any of the following modifiers to the field name: + its entirety to stdout. If there are multiple hist triggers + attached to an event, there will be a table for each trigger in the + output. Each printed hash table entry is a simple list of the keys + and values comprising the entry; keys are printed first and are + delineated by curly braces, and are followed by the set of value + fields for the entry. By default, numeric fields are displayed as + base-10 integers. This can be modified by appending any of the + following modifiers to the field name: .hex display a number as a hex value .sym display an address as a symbol @@ -1667,3 +1669,143 @@ The following commands are supported: . . . + + The following example demonstrates how multiple hist triggers can be + attached to a given event. This capability can be useful for + creating a set of different summaries derived from the same set of + events, or for comparing the effects of different filters, among + other things. + + # echo 'hist:keys=skbaddr.hex:vals=len if len < 0' >> \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + # echo 'hist:keys=skbaddr.hex:vals=len if len > 4096' >> \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + # echo 'hist:keys=skbaddr.hex:vals=len if len == 256' >> \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + # echo 'hist:keys=skbaddr.hex:vals=len' >> \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + # echo 'hist:keys=len:vals=common_preempt_count' >> \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + + The above set of commands create four triggers differing only in + their filters, along with a completely different though fairly + nonsensical trigger. Note that in order to append multiple hist + triggers to the same file, you should use the '>>' operator to + append them ('>' will also add the new hist trigger, but will remove + any existing hist triggers beforehand). + + Displaying the contents of the 'hist' file for the event shows the + contents of all five histograms: + + # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist + + # event histogram + # + # trigger info: hist:keys=len:vals=hitcount,common_preempt_count:sort=hitcount:size=2048 [active] + # + + { len: 176 } hitcount: 1 common_preempt_count: 0 + { len: 223 } hitcount: 1 common_preempt_count: 0 + { len: 4854 } hitcount: 1 common_preempt_count: 0 + { len: 395 } hitcount: 1 common_preempt_count: 0 + { len: 177 } hitcount: 1 common_preempt_count: 0 + { len: 446 } hitcount: 1 common_preempt_count: 0 + { len: 1601 } hitcount: 1 common_preempt_count: 0 + . + . + . + { len: 1280 } hitcount: 66 common_preempt_count: 0 + { len: 116 } hitcount: 81 common_preempt_count: 40 + { len: 708 } hitcount: 112 common_preempt_count: 0 + { len: 46 } hitcount: 221 common_preempt_count: 0 + { len: 1264 } hitcount: 458 common_preempt_count: 0 + + Totals: + Hits: 1428 + Entries: 147 + Dropped: 0 + + + # event histogram + # + # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active] + # + + { skbaddr: ffff8800baee5e00 } hitcount: 1 len: 130 + { skbaddr: ffff88005f3d5600 } hitcount: 1 len: 1280 + { skbaddr: ffff88005f3d4900 } hitcount: 1 len: 1280 + { skbaddr: ffff88009fed6300 } hitcount: 1 len: 115 + { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 115 + { skbaddr: ffff88008cdb1900 } hitcount: 1 len: 46 + { skbaddr: ffff880064b5ef00 } hitcount: 1 len: 118 + { skbaddr: ffff880044e3c700 } hitcount: 1 len: 60 + { skbaddr: ffff880100065900 } hitcount: 1 len: 46 + { skbaddr: ffff8800d46bd500 } hitcount: 1 len: 116 + { skbaddr: ffff88005f3d5f00 } hitcount: 1 len: 1280 + { skbaddr: ffff880100064700 } hitcount: 1 len: 365 + { skbaddr: ffff8800badb6f00 } hitcount: 1 len: 60 + . + . + . + { skbaddr: ffff88009fe0be00 } hitcount: 27 len: 24677 + { skbaddr: ffff88009fe0a400 } hitcount: 27 len: 23052 + { skbaddr: ffff88009fe0b700 } hitcount: 31 len: 25589 + { skbaddr: ffff88009fe0b600 } hitcount: 32 len: 27326 + { skbaddr: ffff88006a462800 } hitcount: 68 len: 71678 + { skbaddr: ffff88006a463700 } hitcount: 70 len: 72678 + { skbaddr: ffff88006a462b00 } hitcount: 71 len: 77589 + { skbaddr: ffff88006a463600 } hitcount: 73 len: 71307 + { skbaddr: ffff88006a462200 } hitcount: 81 len: 81032 + + Totals: + Hits: 1451 + Entries: 318 + Dropped: 0 + + + # event histogram + # + # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len == 256 [active] + # + + + Totals: + Hits: 0 + Entries: 0 + Dropped: 0 + + + # event histogram + # + # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len > 4096 [active] + # + + { skbaddr: ffff88009fd2c300 } hitcount: 1 len: 7212 + { skbaddr: ffff8800d2bcce00 } hitcount: 1 len: 7212 + { skbaddr: ffff8800d2bcd700 } hitcount: 1 len: 7212 + { skbaddr: ffff8800d2bcda00 } hitcount: 1 len: 21492 + { skbaddr: ffff8800ae2e2d00 } hitcount: 1 len: 7212 + { skbaddr: ffff8800d2bcdb00 } hitcount: 1 len: 7212 + { skbaddr: ffff88006a4df500 } hitcount: 1 len: 4854 + { skbaddr: ffff88008ce47b00 } hitcount: 1 len: 18636 + { skbaddr: ffff8800ae2e2200 } hitcount: 1 len: 12924 + { skbaddr: ffff88005f3e1000 } hitcount: 1 len: 4356 + { skbaddr: ffff8800d2bcdc00 } hitcount: 2 len: 24420 + { skbaddr: ffff8800d2bcc200 } hitcount: 2 len: 12996 + + Totals: + Hits: 14 + Entries: 12 + Dropped: 0 + + + # event histogram + # + # trigger info: hist:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 if len < 0 [active] + # + + + Totals: + Hits: 0 + Entries: 0 + Dropped: 0 diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 8430145bea12..e89b2ed76d2d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3856,9 +3856,11 @@ static const char readme_msg[] = "\t sort field. The 'size' parameter can be used to specify more\n" "\t or fewer than the default 2048 entries for the hashtable size.\n\n" "\t Reading the 'hist' file for the event will dump the hash\n" - "\t table in its entirety to stdout. The default format used to\n" - "\t display a given field can be modified by appending any of the\n" - "\t following modifiers to the field name, as applicable:\n\n" + "\t table in its entirety to stdout. If there are multiple hist\n" + "\t triggers attached to an event, there will be a table for each\n" + "\t trigger in the output. The default format used to display a\n" + "\t given field can be modified by appending any of the following\n" + "\t modifiers to the field name, as applicable:\n\n" "\t .hex display a number as a hex value\n" "\t .sym display an address as a symbol\n" "\t .sym-offset display an address as a symbol and offset\n" diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 5d4f02792440..4b02f8ab4dd3 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -1032,33 +1032,18 @@ static int print_entries(struct seq_file *m, return n_entries; } -static int hist_show(struct seq_file *m, void *v) +static void hist_trigger_show(struct seq_file *m, + struct event_trigger_data *data, int n) { - struct event_trigger_data *test, *data = NULL; - struct trace_event_file *event_file; struct hist_trigger_data *hist_data; int n_entries, ret = 0; - mutex_lock(&event_mutex); - - event_file = event_file_data(m->private); - if (unlikely(!event_file)) { - ret = -ENODEV; - goto out_unlock; - } - - list_for_each_entry_rcu(test, &event_file->triggers, list) { - if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { - data = test; - break; - } - } - if (!data) - goto out_unlock; + if (n > 0) + seq_puts(m, "\n\n"); seq_puts(m, "# event histogram\n#\n# trigger info: "); data->ops->print(m, data->ops, data); - seq_puts(m, "\n"); + seq_puts(m, "#\n\n"); hist_data = data->private_data; n_entries = print_entries(m, hist_data); @@ -1070,6 +1055,27 @@ static int hist_show(struct seq_file *m, void *v) seq_printf(m, "\nTotals:\n Hits: %llu\n Entries: %u\n Dropped: %llu\n", (u64)atomic64_read(&hist_data->map->hits), n_entries, (u64)atomic64_read(&hist_data->map->drops)); +} + +static int hist_show(struct seq_file *m, void *v) +{ + struct event_trigger_data *data; + struct trace_event_file *event_file; + int n = 0, ret = 0; + + mutex_lock(&event_mutex); + + event_file = event_file_data(m->private); + if (unlikely(!event_file)) { + ret = -ENODEV; + goto out_unlock; + } + + list_for_each_entry_rcu(data, &event_file->triggers, list) { + if (data->cmd_ops->trigger_type == ETT_EVENT_HIST) + hist_trigger_show(m, data, n++); + } + out_unlock: mutex_unlock(&event_mutex); @@ -1233,6 +1239,54 @@ static void hist_clear(struct event_trigger_data *data) data->paused = paused; } +static bool hist_trigger_match(struct event_trigger_data *data, + struct event_trigger_data *data_test) +{ + struct tracing_map_sort_key *sort_key, *sort_key_test; + struct hist_trigger_data *hist_data, *hist_data_test; + struct hist_field *key_field, *key_field_test; + unsigned int i; + + hist_data = data->private_data; + hist_data_test = data_test->private_data; + + if (hist_data->n_vals != hist_data_test->n_vals || + hist_data->n_fields != hist_data_test->n_fields || + hist_data->n_sort_keys != hist_data_test->n_sort_keys) + return false; + + if ((data->filter_str && !data_test->filter_str) || + (!data->filter_str && data_test->filter_str)) + return false; + + for_each_hist_field(i, hist_data) { + key_field = hist_data->fields[i]; + key_field_test = hist_data_test->fields[i]; + + if (key_field->flags != key_field_test->flags) + return false; + if (key_field->field != key_field_test->field) + return false; + if (key_field->offset != key_field_test->offset) + return false; + } + + for (i = 0; i < hist_data->n_sort_keys; i++) { + sort_key = &hist_data->sort_keys[i]; + sort_key_test = &hist_data_test->sort_keys[i]; + + if (sort_key->field_idx != sort_key_test->field_idx || + sort_key->descending != sort_key_test->descending) + return false; + } + + if (data->filter_str && + (strcmp(data->filter_str, data_test->filter_str) != 0)) + return false; + + return true; +} + static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file) @@ -1243,6 +1297,8 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, list_for_each_entry_rcu(test, &file->triggers, list) { if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (!hist_trigger_match(data, test)) + continue; if (hist_data->attrs->pause) test->paused = true; else if (hist_data->attrs->cont) @@ -1282,6 +1338,44 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, return ret; } +static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops, + struct event_trigger_data *data, + struct trace_event_file *file) +{ + struct event_trigger_data *test; + bool unregistered = false; + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + if (!hist_trigger_match(data, test)) + continue; + unregistered = true; + list_del_rcu(&test->list); + trace_event_trigger_enable_disable(file, 0); + update_cond_flag(file); + break; + } + } + + if (unregistered && test->ops->free) + test->ops->free(test->ops, test); +} + +static void hist_unreg_all(struct trace_event_file *file) +{ + struct event_trigger_data *test; + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { + list_del_rcu(&test->list); + trace_event_trigger_enable_disable(file, 0); + update_cond_flag(file); + if (test->ops->free) + test->ops->free(test->ops, test); + } + } +} + static int event_hist_trigger_func(struct event_command *cmd_ops, struct trace_event_file *file, char *glob, char *cmd, char *param) @@ -1331,22 +1425,19 @@ static int event_hist_trigger_func(struct event_command *cmd_ops, trigger_data->private_data = hist_data; + /* if param is non-empty, it's supposed to be a filter */ + if (param && cmd_ops->set_filter) { + ret = cmd_ops->set_filter(param, trigger_data, file); + if (ret < 0) + goto out_free; + } + if (glob[0] == '!') { cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); ret = 0; goto out_free; } - if (!param) /* if param is non-empty, it's supposed to be a filter */ - goto out_reg; - - if (!cmd_ops->set_filter) - goto out_reg; - - ret = cmd_ops->set_filter(param, trigger_data, file); - if (ret < 0) - goto out_free; - out_reg: ret = cmd_ops->reg(glob, trigger_ops, trigger_data, file); /* * The above returns on success the # of triggers registered, @@ -1379,7 +1470,8 @@ static struct event_command trigger_hist_cmd = { .flags = EVENT_CMD_FL_NEEDS_REC, .func = event_hist_trigger_func, .reg = hist_register_trigger, - .unreg = unregister_trigger, + .unreg = hist_unregister_trigger, + .unreg_all = hist_unreg_all, .get_trigger_ops = event_hist_get_trigger_ops, .set_filter = set_trigger_filter, }; @@ -1406,7 +1498,6 @@ hist_enable_trigger(struct event_trigger_data *data, void *rec) test->paused = false; else test->paused = true; - break; } } } @@ -1469,12 +1560,28 @@ hist_enable_get_trigger_ops(char *cmd, char *param) return ops; } +static void hist_enable_unreg_all(struct trace_event_file *file) +{ + struct event_trigger_data *test; + + list_for_each_entry_rcu(test, &file->triggers, list) { + if (test->cmd_ops->trigger_type == ETT_HIST_ENABLE) { + list_del_rcu(&test->list); + update_cond_flag(file); + trace_event_trigger_enable_disable(file, 0); + if (test->ops->free) + test->ops->free(test->ops, test); + } + } +} + static struct event_command trigger_hist_enable_cmd = { .name = ENABLE_HIST_STR, .trigger_type = ETT_HIST_ENABLE, .func = event_enable_trigger_func, .reg = event_enable_register_trigger, .unreg = event_enable_unregister_trigger, + .unreg_all = hist_enable_unreg_all, .get_trigger_ops = hist_enable_get_trigger_ops, .set_filter = set_trigger_filter, }; @@ -1485,6 +1592,7 @@ static struct event_command trigger_hist_disable_cmd = { .func = event_enable_trigger_func, .reg = event_enable_register_trigger, .unreg = event_enable_unregister_trigger, + .unreg_all = hist_enable_unreg_all, .get_trigger_ops = hist_enable_get_trigger_ops, .set_filter = set_trigger_filter, }; From db1388b4ffa9e31e9ff0abacc3bdb121bec8c688 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:58 -0600 Subject: [PATCH 24/45] tracing: Add support for named triggers Named triggers are sets of triggers that share a common set of trigger data. An example of functionality that could benefit from this type of capability would be a set of inlined probes that would each contribute event counts, for example, to a shared counter data structure. The first named trigger registered with a given name owns the common trigger data that the others subsequently registered with the same name will reference. The functions defined here allow users to add, delete, and find named triggers. It also adds functions to pause and unpause named triggers; since named triggers act upon common data, they should also be paused and unpaused as a group. Link: http://lkml.kernel.org/r/c09ff648360f65b10a3e321eddafe18060b4a04f.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- kernel/trace/trace.h | 13 +++ kernel/trace/trace_events_trigger.c | 143 ++++++++++++++++++++++++++++ 2 files changed, 156 insertions(+) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index cab1f4bfe85b..727a3d28bce5 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1184,7 +1184,11 @@ struct event_trigger_data { char *filter_str; void *private_data; bool paused; + bool paused_tmp; struct list_head list; + char *name; + struct list_head named_list; + struct event_trigger_data *named_data; }; /* Avoid typos */ @@ -1227,6 +1231,15 @@ extern void unregister_trigger(char *glob, struct event_trigger_ops *ops, extern int set_trigger_filter(char *filter_str, struct event_trigger_data *trigger_data, struct trace_event_file *file); +extern struct event_trigger_data *find_named_trigger(const char *name); +extern bool is_named_trigger(struct event_trigger_data *test); +extern int save_named_trigger(const char *name, + struct event_trigger_data *data); +extern void del_named_trigger(struct event_trigger_data *data); +extern void pause_named_trigger(struct event_trigger_data *data); +extern void unpause_named_trigger(struct event_trigger_data *data); +extern void set_named_trigger_data(struct event_trigger_data *data, + struct event_trigger_data *named_data); extern int register_event_command(struct event_command *cmd); extern int unregister_event_command(struct event_command *cmd); extern int register_trigger_hist_enable_disable_cmds(void); diff --git a/kernel/trace/trace_events_trigger.c b/kernel/trace/trace_events_trigger.c index d133f2094566..a975571cde24 100644 --- a/kernel/trace/trace_events_trigger.c +++ b/kernel/trace/trace_events_trigger.c @@ -641,6 +641,7 @@ event_trigger_callback(struct event_command *cmd_ops, trigger_data->ops = trigger_ops; trigger_data->cmd_ops = cmd_ops; INIT_LIST_HEAD(&trigger_data->list); + INIT_LIST_HEAD(&trigger_data->named_list); if (glob[0] == '!') { cmd_ops->unreg(glob+1, trigger_ops, trigger_data, file); @@ -764,6 +765,148 @@ int set_trigger_filter(char *filter_str, return ret; } +static LIST_HEAD(named_triggers); + +/** + * find_named_trigger - Find the common named trigger associated with @name + * @name: The name of the set of named triggers to find the common data for + * + * Named triggers are sets of triggers that share a common set of + * trigger data. The first named trigger registered with a given name + * owns the common trigger data that the others subsequently + * registered with the same name will reference. This function + * returns the common trigger data associated with that first + * registered instance. + * + * Return: the common trigger data for the given named trigger on + * success, NULL otherwise. + */ +struct event_trigger_data *find_named_trigger(const char *name) +{ + struct event_trigger_data *data; + + if (!name) + return NULL; + + list_for_each_entry(data, &named_triggers, named_list) { + if (data->named_data) + continue; + if (strcmp(data->name, name) == 0) + return data; + } + + return NULL; +} + +/** + * is_named_trigger - determine if a given trigger is a named trigger + * @test: The trigger data to test + * + * Return: true if 'test' is a named trigger, false otherwise. + */ +bool is_named_trigger(struct event_trigger_data *test) +{ + struct event_trigger_data *data; + + list_for_each_entry(data, &named_triggers, named_list) { + if (test == data) + return true; + } + + return false; +} + +/** + * save_named_trigger - save the trigger in the named trigger list + * @name: The name of the named trigger set + * @data: The trigger data to save + * + * Return: 0 if successful, negative error otherwise. + */ +int save_named_trigger(const char *name, struct event_trigger_data *data) +{ + data->name = kstrdup(name, GFP_KERNEL); + if (!data->name) + return -ENOMEM; + + list_add(&data->named_list, &named_triggers); + + return 0; +} + +/** + * del_named_trigger - delete a trigger from the named trigger list + * @data: The trigger data to delete + */ +void del_named_trigger(struct event_trigger_data *data) +{ + kfree(data->name); + data->name = NULL; + + list_del(&data->named_list); +} + +static void __pause_named_trigger(struct event_trigger_data *data, bool pause) +{ + struct event_trigger_data *test; + + list_for_each_entry(test, &named_triggers, named_list) { + if (strcmp(test->name, data->name) == 0) { + if (pause) { + test->paused_tmp = test->paused; + test->paused = true; + } else { + test->paused = test->paused_tmp; + } + } + } +} + +/** + * pause_named_trigger - Pause all named triggers with the same name + * @data: The trigger data of a named trigger to pause + * + * Pauses a named trigger along with all other triggers having the + * same name. Because named triggers share a common set of data, + * pausing only one is meaningless, so pausing one named trigger needs + * to pause all triggers with the same name. + */ +void pause_named_trigger(struct event_trigger_data *data) +{ + __pause_named_trigger(data, true); +} + +/** + * unpause_named_trigger - Un-pause all named triggers with the same name + * @data: The trigger data of a named trigger to unpause + * + * Un-pauses a named trigger along with all other triggers having the + * same name. Because named triggers share a common set of data, + * unpausing only one is meaningless, so unpausing one named trigger + * needs to unpause all triggers with the same name. + */ +void unpause_named_trigger(struct event_trigger_data *data) +{ + __pause_named_trigger(data, false); +} + +/** + * set_named_trigger_data - Associate common named trigger data + * @data: The trigger data of a named trigger to unpause + * + * Named triggers are sets of triggers that share a common set of + * trigger data. The first named trigger registered with a given name + * owns the common trigger data that the others subsequently + * registered with the same name will reference. This function + * associates the common trigger data from the first trigger with the + * given trigger. + */ +void set_named_trigger_data(struct event_trigger_data *data, + struct event_trigger_data *named_data) +{ + data->named_data = named_data; +} + static void traceon_trigger(struct event_trigger_data *data, void *rec) { From 5463bfda327b1f7310556ef3136533e27c774f13 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Thu, 3 Mar 2016 12:54:59 -0600 Subject: [PATCH 25/45] tracing: Add support for named hist triggers Allow users to define 'named' hist triggers. All triggers created with the same 'name=xxx' option will update the same shared histogram data. This expands the hist trigger syntax from this: # echo hist:keys=xxx ... [ if filter] > event/trigger to this: # echo hist:name=xxx:keys=xxx ... [ if filter] > event/trigger Named histograms must use a 'compatible' set of keys and values, which means each event added to a set of named triggers must have the same names and types. Reading the 'hist' file of any of the participating events will produce the same output as any other participating event, which is to be expected since they share the same data. Link: http://lkml.kernel.org/r/1dbc84ee3322a75daaf5b3ef1d0cc0a2fb682fc7.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Tested-by: Masami Hiramatsu Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- Documentation/trace/events.txt | 274 ++++++++++++++++++++++++++++++- kernel/trace/trace.c | 14 +- kernel/trace/trace_events_hist.c | 148 +++++++++++++++-- 3 files changed, 407 insertions(+), 29 deletions(-) diff --git a/Documentation/trace/events.txt b/Documentation/trace/events.txt index cc0216760b78..08d74d75150d 100644 --- a/Documentation/trace/events.txt +++ b/Documentation/trace/events.txt @@ -524,7 +524,7 @@ The following commands are supported: hist:keys=[:values=] [:sort=][:size=#entries][:pause][:continue] - [:clear] [if ] + [:clear][:name=histname1] [if ] When a matching event is hit, an entry is added to a hash table using the key(s) and value(s) named. Keys and values correspond to @@ -546,18 +546,28 @@ The following commands are supported: specified by the 'sort' keyword. If more than one field is specified, the result will be a 'sort within a sort': the first key is taken to be the primary sort key and the second the secondary - key. + key. If a hist trigger is given a name using the 'name' parameter, + its histogram data will be shared with other triggers of the same + name, and trigger hits will update this common data. Only triggers + with 'compatible' fields can be combined in this way; triggers are + 'compatible' if the fields named in the trigger share the same + number and type of fields and those fields also have the same names. + Note that any two events always share the compatible 'hitcount' and + 'stacktrace' fields and can therefore be combined using those + fields, however pointless that may be. 'hist' triggers add a 'hist' file to each event's subdirectory. Reading the 'hist' file for the event will dump the hash table in its entirety to stdout. If there are multiple hist triggers attached to an event, there will be a table for each trigger in the - output. Each printed hash table entry is a simple list of the keys - and values comprising the entry; keys are printed first and are - delineated by curly braces, and are followed by the set of value - fields for the entry. By default, numeric fields are displayed as - base-10 integers. This can be modified by appending any of the - following modifiers to the field name: + output. The table displayed for a named trigger will be the same as + any other instance having the same name. Each printed hash table + entry is a simple list of the keys and values comprising the entry; + keys are printed first and are delineated by curly braces, and are + followed by the set of value fields for the entry. By default, + numeric fields are displayed as base-10 integers. This can be + modified by appending any of the following modifiers to the field + name: .hex display a number as a hex value .sym display an address as a symbol @@ -1809,3 +1819,251 @@ The following commands are supported: Hits: 0 Entries: 0 Dropped: 0 + + Named triggers can be used to have triggers share a common set of + histogram data. This capability is mostly useful for combining the + output of events generated by tracepoints contained inside inline + functions, but names can be used in a hist trigger on any event. + For example, these two triggers when hit will update the same 'len' + field in the shared 'foo' histogram data: + + # echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \ + /sys/kernel/debug/tracing/events/net/netif_receive_skb/trigger + # echo 'hist:name=foo:keys=skbaddr.hex:vals=len' > \ + /sys/kernel/debug/tracing/events/net/netif_rx/trigger + + You can see that they're updating common histogram data by reading + each event's hist files at the same time: + + # cat /sys/kernel/debug/tracing/events/net/netif_receive_skb/hist; + cat /sys/kernel/debug/tracing/events/net/netif_rx/hist + + # event histogram + # + # trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active] + # + + { skbaddr: ffff88000ad53500 } hitcount: 1 len: 46 + { skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76 + { skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468 + { skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46 + { skbaddr: ffff88009ff09100 } hitcount: 1 len: 52 + { skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168 + { skbaddr: ffff88006a54f400 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260 + { skbaddr: ffff880064505000 } hitcount: 1 len: 46 + { skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32 + { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46 + { skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44 + { skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168 + { skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40 + { skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40 + { skbaddr: ffff880064505f00 } hitcount: 1 len: 174 + { skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160 + { skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76 + { skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32 + { skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988 + { skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46 + { skbaddr: ffff88002e37a200 } hitcount: 1 len: 44 + { skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676 + { skbaddr: ffff88000ad52600 } hitcount: 2 len: 107 + { skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92 + { skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142 + { skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220 + { skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92 + { skbaddr: ffff8800d021f800 } hitcount: 2 len: 92 + { skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675 + { skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138 + { skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138 + { skbaddr: ffff88002e37a100 } hitcount: 4 len: 184 + { skbaddr: ffff880064504400 } hitcount: 4 len: 184 + { skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184 + { skbaddr: ffff88000ad53700 } hitcount: 5 len: 230 + { skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196 + { skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276 + { skbaddr: ffff88006a54f900 } hitcount: 6 len: 276 + + Totals: + Hits: 81 + Entries: 42 + Dropped: 0 + # event histogram + # + # trigger info: hist:name=foo:keys=skbaddr.hex:vals=hitcount,len:sort=hitcount:size=2048 [active] + # + + { skbaddr: ffff88000ad53500 } hitcount: 1 len: 46 + { skbaddr: ffff8800af5a1500 } hitcount: 1 len: 76 + { skbaddr: ffff8800d62a1900 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bccb00 } hitcount: 1 len: 468 + { skbaddr: ffff8800d3c69900 } hitcount: 1 len: 46 + { skbaddr: ffff88009ff09100 } hitcount: 1 len: 52 + { skbaddr: ffff88010f13ab00 } hitcount: 1 len: 168 + { skbaddr: ffff88006a54f400 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bcc500 } hitcount: 1 len: 260 + { skbaddr: ffff880064505000 } hitcount: 1 len: 46 + { skbaddr: ffff8800baf24e00 } hitcount: 1 len: 32 + { skbaddr: ffff88009fe0ad00 } hitcount: 1 len: 46 + { skbaddr: ffff8800d3edff00 } hitcount: 1 len: 44 + { skbaddr: ffff88009fe0b400 } hitcount: 1 len: 168 + { skbaddr: ffff8800a1c55a00 } hitcount: 1 len: 40 + { skbaddr: ffff8800d2bcd100 } hitcount: 1 len: 40 + { skbaddr: ffff880064505f00 } hitcount: 1 len: 174 + { skbaddr: ffff8800a8bff200 } hitcount: 1 len: 160 + { skbaddr: ffff880044e3cc00 } hitcount: 1 len: 76 + { skbaddr: ffff8800a8bfe700 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bcdc00 } hitcount: 1 len: 32 + { skbaddr: ffff8800a1f64800 } hitcount: 1 len: 46 + { skbaddr: ffff8800d2bcde00 } hitcount: 1 len: 988 + { skbaddr: ffff88006a5dea00 } hitcount: 1 len: 46 + { skbaddr: ffff88002e37a200 } hitcount: 1 len: 44 + { skbaddr: ffff8800a1f32c00 } hitcount: 2 len: 676 + { skbaddr: ffff88000ad52600 } hitcount: 2 len: 107 + { skbaddr: ffff8800a1f91e00 } hitcount: 2 len: 92 + { skbaddr: ffff8800af5a0200 } hitcount: 2 len: 142 + { skbaddr: ffff8800d2bcc600 } hitcount: 2 len: 220 + { skbaddr: ffff8800ba36f500 } hitcount: 2 len: 92 + { skbaddr: ffff8800d021f800 } hitcount: 2 len: 92 + { skbaddr: ffff8800a1f33600 } hitcount: 2 len: 675 + { skbaddr: ffff8800a8bfff00 } hitcount: 3 len: 138 + { skbaddr: ffff8800d62a1300 } hitcount: 3 len: 138 + { skbaddr: ffff88002e37a100 } hitcount: 4 len: 184 + { skbaddr: ffff880064504400 } hitcount: 4 len: 184 + { skbaddr: ffff8800a8bfec00 } hitcount: 4 len: 184 + { skbaddr: ffff88000ad53700 } hitcount: 5 len: 230 + { skbaddr: ffff8800d2bcdb00 } hitcount: 5 len: 196 + { skbaddr: ffff8800a1f90000 } hitcount: 6 len: 276 + { skbaddr: ffff88006a54f900 } hitcount: 6 len: 276 + + Totals: + Hits: 81 + Entries: 42 + Dropped: 0 + + And here's an example that shows how to combine histogram data from + any two events even if they don't share any 'compatible' fields + other than 'hitcount' and 'stacktrace'. These commands create a + couple of triggers named 'bar' using those fields: + + # echo 'hist:name=bar:key=stacktrace:val=hitcount' > \ + /sys/kernel/debug/tracing/events/sched/sched_process_fork/trigger + # echo 'hist:name=bar:key=stacktrace:val=hitcount' > \ + /sys/kernel/debug/tracing/events/net/netif_rx/trigger + + And displaying the output of either shows some interesting if + somewhat confusing output: + + # cat /sys/kernel/debug/tracing/events/sched/sched_process_fork/hist + # cat /sys/kernel/debug/tracing/events/net/netif_rx/hist + + # event histogram + # + # trigger info: hist:name=bar:keys=stacktrace:vals=hitcount:sort=hitcount:size=2048 [active] + # + + { stacktrace: + _do_fork+0x18e/0x330 + kernel_thread+0x29/0x30 + kthreadd+0x154/0x1b0 + ret_from_fork+0x3f/0x70 + } hitcount: 1 + { stacktrace: + netif_rx_internal+0xb2/0xd0 + netif_rx_ni+0x20/0x70 + dev_loopback_xmit+0xaa/0xd0 + ip_mc_output+0x126/0x240 + ip_local_out_sk+0x31/0x40 + igmp_send_report+0x1e9/0x230 + igmp_timer_expire+0xe9/0x120 + call_timer_fn+0x39/0xf0 + run_timer_softirq+0x1e1/0x290 + __do_softirq+0xfd/0x290 + irq_exit+0x98/0xb0 + smp_apic_timer_interrupt+0x4a/0x60 + apic_timer_interrupt+0x6d/0x80 + cpuidle_enter+0x17/0x20 + call_cpuidle+0x3b/0x60 + cpu_startup_entry+0x22d/0x310 + } hitcount: 1 + { stacktrace: + netif_rx_internal+0xb2/0xd0 + netif_rx_ni+0x20/0x70 + dev_loopback_xmit+0xaa/0xd0 + ip_mc_output+0x17f/0x240 + ip_local_out_sk+0x31/0x40 + ip_send_skb+0x1a/0x50 + udp_send_skb+0x13e/0x270 + udp_sendmsg+0x2bf/0x980 + inet_sendmsg+0x67/0xa0 + sock_sendmsg+0x38/0x50 + SYSC_sendto+0xef/0x170 + SyS_sendto+0xe/0x10 + entry_SYSCALL_64_fastpath+0x12/0x6a + } hitcount: 2 + { stacktrace: + netif_rx_internal+0xb2/0xd0 + netif_rx+0x1c/0x60 + loopback_xmit+0x6c/0xb0 + dev_hard_start_xmit+0x219/0x3a0 + __dev_queue_xmit+0x415/0x4f0 + dev_queue_xmit_sk+0x13/0x20 + ip_finish_output2+0x237/0x340 + ip_finish_output+0x113/0x1d0 + ip_output+0x66/0xc0 + ip_local_out_sk+0x31/0x40 + ip_send_skb+0x1a/0x50 + udp_send_skb+0x16d/0x270 + udp_sendmsg+0x2bf/0x980 + inet_sendmsg+0x67/0xa0 + sock_sendmsg+0x38/0x50 + ___sys_sendmsg+0x14e/0x270 + } hitcount: 76 + { stacktrace: + netif_rx_internal+0xb2/0xd0 + netif_rx+0x1c/0x60 + loopback_xmit+0x6c/0xb0 + dev_hard_start_xmit+0x219/0x3a0 + __dev_queue_xmit+0x415/0x4f0 + dev_queue_xmit_sk+0x13/0x20 + ip_finish_output2+0x237/0x340 + ip_finish_output+0x113/0x1d0 + ip_output+0x66/0xc0 + ip_local_out_sk+0x31/0x40 + ip_send_skb+0x1a/0x50 + udp_send_skb+0x16d/0x270 + udp_sendmsg+0x2bf/0x980 + inet_sendmsg+0x67/0xa0 + sock_sendmsg+0x38/0x50 + ___sys_sendmsg+0x269/0x270 + } hitcount: 77 + { stacktrace: + netif_rx_internal+0xb2/0xd0 + netif_rx+0x1c/0x60 + loopback_xmit+0x6c/0xb0 + dev_hard_start_xmit+0x219/0x3a0 + __dev_queue_xmit+0x415/0x4f0 + dev_queue_xmit_sk+0x13/0x20 + ip_finish_output2+0x237/0x340 + ip_finish_output+0x113/0x1d0 + ip_output+0x66/0xc0 + ip_local_out_sk+0x31/0x40 + ip_send_skb+0x1a/0x50 + udp_send_skb+0x16d/0x270 + udp_sendmsg+0x2bf/0x980 + inet_sendmsg+0x67/0xa0 + sock_sendmsg+0x38/0x50 + SYSC_sendto+0xef/0x170 + } hitcount: 88 + { stacktrace: + _do_fork+0x18e/0x330 + SyS_clone+0x19/0x20 + entry_SYSCALL_64_fastpath+0x12/0x6a + } hitcount: 244 + + Totals: + Hits: 489 + Entries: 7 + Dropped: 0 diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e89b2ed76d2d..4e342d354c12 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3842,6 +3842,7 @@ static const char readme_msg[] = "\t [:sort=]\n" "\t [:size=#entries]\n" "\t [:pause][:continue][:clear]\n" + "\t [:name=histname1]\n" "\t [if ]\n\n" "\t When a matching event is hit, an entry is added to a hash\n" "\t table using the key(s) and value(s) named, and the value of a\n" @@ -3854,13 +3855,18 @@ static const char readme_msg[] = "\t specified using the 'sort' keyword. The sort direction can\n" "\t be modified by appending '.descending' or '.ascending' to a\n" "\t sort field. The 'size' parameter can be used to specify more\n" - "\t or fewer than the default 2048 entries for the hashtable size.\n\n" + "\t or fewer than the default 2048 entries for the hashtable size.\n" + "\t If a hist trigger is given a name using the 'name' parameter,\n" + "\t its histogram data will be shared with other triggers of the\n" + "\t same name, and trigger hits will update this common data.\n\n" "\t Reading the 'hist' file for the event will dump the hash\n" "\t table in its entirety to stdout. If there are multiple hist\n" "\t triggers attached to an event, there will be a table for each\n" - "\t trigger in the output. The default format used to display a\n" - "\t given field can be modified by appending any of the following\n" - "\t modifiers to the field name, as applicable:\n\n" + "\t trigger in the output. The table displayed for a named\n" + "\t trigger will be the same as any other instance having the\n" + "\t same name. The default format used to display a given field\n" + "\t can be modified by appending any of the following modifiers\n" + "\t to the field name, as applicable:\n\n" "\t .hex display a number as a hex value\n" "\t .sym display an address as a symbol\n" "\t .sym-offset display an address as a symbol and offset\n" diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 4b02f8ab4dd3..bdea5603cbde 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -117,6 +117,7 @@ struct hist_trigger_attrs { char *keys_str; char *vals_str; char *sort_key_str; + char *name; bool pause; bool cont; bool clear; @@ -200,6 +201,7 @@ static void destroy_hist_trigger_attrs(struct hist_trigger_attrs *attrs) if (!attrs) return; + kfree(attrs->name); kfree(attrs->sort_key_str); kfree(attrs->keys_str); kfree(attrs->vals_str); @@ -227,6 +229,8 @@ static struct hist_trigger_attrs *parse_hist_trigger_attrs(char *trigger_str) attrs->vals_str = kstrdup(str, GFP_KERNEL); else if (strncmp(str, "sort=", strlen("sort=")) == 0) attrs->sort_key_str = kstrdup(str, GFP_KERNEL); + else if (strncmp(str, "name=", strlen("name=")) == 0) + attrs->name = kstrdup(str, GFP_KERNEL); else if (strcmp(str, "pause") == 0) attrs->pause = true; else if ((strcmp(str, "cont") == 0) || @@ -1131,7 +1135,12 @@ static int event_hist_trigger_print(struct seq_file *m, struct hist_field *key_field; unsigned int i; - seq_puts(m, "hist:keys="); + seq_puts(m, "hist:"); + + if (data->name) + seq_printf(m, "%s:", data->name); + + seq_puts(m, "keys="); for_each_hist_key_field(i, hist_data) { key_field = hist_data->fields[i]; @@ -1196,6 +1205,19 @@ static int event_hist_trigger_print(struct seq_file *m, return 0; } +static int event_hist_trigger_init(struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + struct hist_trigger_data *hist_data = data->private_data; + + if (!data->ref && hist_data->attrs->name) + save_named_trigger(hist_data->attrs->name, data); + + data->ref++; + + return 0; +} + static void event_hist_trigger_free(struct event_trigger_ops *ops, struct event_trigger_data *data) { @@ -1206,6 +1228,8 @@ static void event_hist_trigger_free(struct event_trigger_ops *ops, data->ref--; if (!data->ref) { + if (data->name) + del_named_trigger(data); trigger_data_free(data); destroy_hist_data(hist_data); } @@ -1214,10 +1238,44 @@ static void event_hist_trigger_free(struct event_trigger_ops *ops, static struct event_trigger_ops event_hist_trigger_ops = { .func = event_hist_trigger, .print = event_hist_trigger_print, - .init = event_trigger_init, + .init = event_hist_trigger_init, .free = event_hist_trigger_free, }; +static int event_hist_trigger_named_init(struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + data->ref++; + + save_named_trigger(data->named_data->name, data); + + event_hist_trigger_init(ops, data->named_data); + + return 0; +} + +static void event_hist_trigger_named_free(struct event_trigger_ops *ops, + struct event_trigger_data *data) +{ + if (WARN_ON_ONCE(data->ref <= 0)) + return; + + event_hist_trigger_free(ops, data->named_data); + + data->ref--; + if (!data->ref) { + del_named_trigger(data); + trigger_data_free(data); + } +} + +static struct event_trigger_ops event_hist_trigger_named_ops = { + .func = event_hist_trigger, + .print = event_hist_trigger_print, + .init = event_hist_trigger_named_init, + .free = event_hist_trigger_named_free, +}; + static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd, char *param) { @@ -1227,26 +1285,54 @@ static struct event_trigger_ops *event_hist_get_trigger_ops(char *cmd, static void hist_clear(struct event_trigger_data *data) { struct hist_trigger_data *hist_data = data->private_data; - bool paused; - paused = data->paused; - data->paused = true; + if (data->name) + pause_named_trigger(data); synchronize_sched(); tracing_map_clear(hist_data->map); - data->paused = paused; + if (data->name) + unpause_named_trigger(data); +} + +static bool compatible_field(struct ftrace_event_field *field, + struct ftrace_event_field *test_field) +{ + if (field == test_field) + return true; + if (field == NULL || test_field == NULL) + return false; + if (strcmp(field->name, test_field->name) != 0) + return false; + if (strcmp(field->type, test_field->type) != 0) + return false; + if (field->size != test_field->size) + return false; + if (field->is_signed != test_field->is_signed) + return false; + + return true; } static bool hist_trigger_match(struct event_trigger_data *data, - struct event_trigger_data *data_test) + struct event_trigger_data *data_test, + struct event_trigger_data *named_data, + bool ignore_filter) { struct tracing_map_sort_key *sort_key, *sort_key_test; struct hist_trigger_data *hist_data, *hist_data_test; struct hist_field *key_field, *key_field_test; unsigned int i; + if (named_data && (named_data != data_test) && + (named_data != data_test->named_data)) + return false; + + if (!named_data && is_named_trigger(data_test)) + return false; + hist_data = data->private_data; hist_data_test = data_test->private_data; @@ -1255,9 +1341,11 @@ static bool hist_trigger_match(struct event_trigger_data *data, hist_data->n_sort_keys != hist_data_test->n_sort_keys) return false; - if ((data->filter_str && !data_test->filter_str) || - (!data->filter_str && data_test->filter_str)) - return false; + if (!ignore_filter) { + if ((data->filter_str && !data_test->filter_str) || + (!data->filter_str && data_test->filter_str)) + return false; + } for_each_hist_field(i, hist_data) { key_field = hist_data->fields[i]; @@ -1265,7 +1353,7 @@ static bool hist_trigger_match(struct event_trigger_data *data, if (key_field->flags != key_field_test->flags) return false; - if (key_field->field != key_field_test->field) + if (!compatible_field(key_field->field, key_field_test->field)) return false; if (key_field->offset != key_field_test->offset) return false; @@ -1280,7 +1368,7 @@ static bool hist_trigger_match(struct event_trigger_data *data, return false; } - if (data->filter_str && + if (!ignore_filter && data->filter_str && (strcmp(data->filter_str, data_test->filter_str) != 0)) return false; @@ -1292,12 +1380,26 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, struct trace_event_file *file) { struct hist_trigger_data *hist_data = data->private_data; - struct event_trigger_data *test; + struct event_trigger_data *test, *named_data = NULL; int ret = 0; + if (hist_data->attrs->name) { + named_data = find_named_trigger(hist_data->attrs->name); + if (named_data) { + if (!hist_trigger_match(data, named_data, named_data, + true)) { + ret = -EINVAL; + goto out; + } + } + } + + if (hist_data->attrs->name && !named_data) + goto new; + list_for_each_entry_rcu(test, &file->triggers, list) { if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { - if (!hist_trigger_match(data, test)) + if (!hist_trigger_match(data, test, named_data, false)) continue; if (hist_data->attrs->pause) test->paused = true; @@ -1310,12 +1412,19 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, goto out; } } - + new: if (hist_data->attrs->cont || hist_data->attrs->clear) { ret = -ENOENT; goto out; } + if (named_data) { + destroy_hist_data(data->private_data); + data->private_data = named_data->private_data; + set_named_trigger_data(data, named_data); + data->ops = &event_hist_trigger_named_ops; + } + if (hist_data->attrs->pause) data->paused = true; @@ -1329,6 +1438,7 @@ static int hist_register_trigger(char *glob, struct event_trigger_ops *ops, ret++; update_cond_flag(file); + if (trace_event_trigger_enable_disable(file, 1) < 0) { list_del_rcu(&data->list); update_cond_flag(file); @@ -1342,12 +1452,16 @@ static void hist_unregister_trigger(char *glob, struct event_trigger_ops *ops, struct event_trigger_data *data, struct trace_event_file *file) { - struct event_trigger_data *test; + struct hist_trigger_data *hist_data = data->private_data; + struct event_trigger_data *test, *named_data = NULL; bool unregistered = false; + if (hist_data->attrs->name) + named_data = find_named_trigger(hist_data->attrs->name); + list_for_each_entry_rcu(test, &file->triggers, list) { if (test->cmd_ops->trigger_type == ETT_EVENT_HIST) { - if (!hist_trigger_match(data, test)) + if (!hist_trigger_match(data, test, named_data, false)) continue; unregistered = true; list_del_rcu(&test->list); From cfa0963dc474fd098d6a7a722dcecfc143a4b377 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 3 Mar 2016 12:55:00 -0600 Subject: [PATCH 26/45] kselftests/ftrace : Add event trigger testcases This adds simple event trigger testcases for ftracetest, which covers following triggers. - traceon-traceoff trigger - enable/disable_event trigger - snapshot trigger - stacktrace trigger - trigger filters Here is the test result. ---- # ./ftracetest test.d/trigger/ === Ftrace unit tests === [1] event trigger - test event enable/disable trigger [PASS] [2] event trigger - test trigger filter [PASS] [3] event trigger - test snapshot-trigger [PASS] [4] event trigger - test stacktrace-trigger [PASS] [5] event trigger - test traceon/off trigger [PASS] # of passed: 5 # of failed: 0 # of unresolved: 0 # of untested: 0 # of unsupported: 0 # of xfailed: 0 # of undefined(test bug): 0 ---- Link: http://lkml.kernel.org/r/12b9c2b289a0dc1e4386e7b77674611a83abca85.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Masami Hiramatsu Cc: Ingo Molnar Cc: Shuah Khan Cc: Namhyung Kim Cc: Tom Zanussi Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- .../testing/selftests/ftrace/test.d/functions | 9 +++ .../test.d/trigger/trigger-eventonoff.tc | 64 +++++++++++++++++++ .../ftrace/test.d/trigger/trigger-filter.tc | 59 +++++++++++++++++ .../ftrace/test.d/trigger/trigger-snapshot.tc | 56 ++++++++++++++++ .../test.d/trigger/trigger-stacktrace.tc | 53 +++++++++++++++ .../test.d/trigger/trigger-traceonoff.tc | 58 +++++++++++++++++ 6 files changed, 299 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-eventonoff.tc create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-filter.tc create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-snapshot.tc create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-stacktrace.tc create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-traceonoff.tc diff --git a/tools/testing/selftests/ftrace/test.d/functions b/tools/testing/selftests/ftrace/test.d/functions index 5d8cd06d920f..c37262f6c269 100644 --- a/tools/testing/selftests/ftrace/test.d/functions +++ b/tools/testing/selftests/ftrace/test.d/functions @@ -14,3 +14,12 @@ enable_tracing() { # start trace recording reset_tracer() { # reset the current tracer echo nop > current_tracer } + +reset_trigger() { # reset all current setting triggers + grep -v ^# events/*/*/trigger | + while read line; do + cmd=`echo $line | cut -f2- -d: | cut -f1 -d" "` + echo "!$cmd" > `echo $line | cut -f1 -d:` + done +} + diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-eventonoff.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-eventonoff.tc new file mode 100644 index 000000000000..1a9445021bf1 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-eventonoff.tc @@ -0,0 +1,64 @@ +#!/bin/sh +# description: event trigger - test event enable/disable trigger + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit $FAIL +} + +if [ ! -f set_event -o ! -d events/sched ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f events/sched/sched_process_fork/trigger ]; then + echo "event trigger is not supported" + exit_unsupported +fi + +reset_tracer +do_reset + +FEATURE=`grep enable_event events/sched/sched_process_fork/trigger` +if [ -z "$FEATURE" ]; then + echo "event enable/disable trigger is not supported" + exit_unsupported +fi + +echo "Test enable_event trigger" +echo 0 > events/sched/sched_switch/enable +echo 'enable_event:sched:sched_switch' > events/sched/sched_process_fork/trigger +( echo "forked") +if [ `cat events/sched/sched_switch/enable` != '1*' ]; then + fail "enable_event trigger on sched_process_fork did not work" +fi + +reset_trigger + +echo "Test disable_event trigger" +echo 1 > events/sched/sched_switch/enable +echo 'disable_event:sched:sched_switch' > events/sched/sched_process_fork/trigger +( echo "forked") +if [ `cat events/sched/sched_switch/enable` != '0*' ]; then + fail "disable_event trigger on sched_process_fork did not work" +fi + +reset_trigger + +echo "Test semantic error for event enable/disable trigger" +! echo 'enable_event:nogroup:noevent' > events/sched/sched_process_fork/trigger +! echo 'disable_event+1' > events/sched/sched_process_fork/trigger +echo 'enable_event:sched:sched_switch' > events/sched/sched_process_fork/trigger +! echo 'enable_event:sched:sched_switch' > events/sched/sched_process_fork/trigger +! echo 'disable_event:sched:sched_switch' > events/sched/sched_process_fork/trigger + +do_reset + +exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-filter.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-filter.tc new file mode 100644 index 000000000000..514e466e198b --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-filter.tc @@ -0,0 +1,59 @@ +#!/bin/sh +# description: event trigger - test trigger filter + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit $FAIL +} + +if [ ! -f set_event -o ! -d events/sched ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f events/sched/sched_process_fork/trigger ]; then + echo "event trigger is not supported" + exit_unsupported +fi + +reset_tracer +do_reset + +echo "Test trigger filter" +echo 1 > tracing_on +echo 'traceoff if child_pid == 0' > events/sched/sched_process_fork/trigger +( echo "forked") +if [ `cat tracing_on` -ne 1 ]; then + fail "traceoff trigger on sched_process_fork did not work" +fi + +reset_trigger + +echo "Test semantic error for trigger filter" +! echo 'traceoff if a' > events/sched/sched_process_fork/trigger +! echo 'traceoff if common_pid=0' > events/sched/sched_process_fork/trigger +! echo 'traceoff if common_pid==b' > events/sched/sched_process_fork/trigger +echo 'traceoff if common_pid == 0' > events/sched/sched_process_fork/trigger +echo '!traceoff' > events/sched/sched_process_fork/trigger +! echo 'traceoff if common_pid == child_pid' > events/sched/sched_process_fork/trigger +echo 'traceoff if common_pid <= 0' > events/sched/sched_process_fork/trigger +echo '!traceoff' > events/sched/sched_process_fork/trigger +echo 'traceoff if common_pid >= 0' > events/sched/sched_process_fork/trigger +echo '!traceoff' > events/sched/sched_process_fork/trigger +echo 'traceoff if parent_pid >= 0 && child_pid >= 0' > events/sched/sched_process_fork/trigger +echo '!traceoff' > events/sched/sched_process_fork/trigger +echo 'traceoff if parent_pid >= 0 || child_pid >= 0' > events/sched/sched_process_fork/trigger +echo '!traceoff' > events/sched/sched_process_fork/trigger + + + +do_reset + +exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-snapshot.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-snapshot.tc new file mode 100644 index 000000000000..f84b80d551a2 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-snapshot.tc @@ -0,0 +1,56 @@ +#!/bin/sh +# description: event trigger - test snapshot-trigger + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit $FAIL +} + +if [ ! -f set_event -o ! -d events/sched ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f events/sched/sched_process_fork/trigger ]; then + echo "event trigger is not supported" + exit_unsupported +fi + +reset_tracer +do_reset + +FEATURE=`grep snapshot events/sched/sched_process_fork/trigger` +if [ -z "$FEATURE" ]; then + echo "snapshot trigger is not supported" + exit_unsupported +fi + +echo "Test snapshot tigger" +echo 0 > snapshot +echo 1 > events/sched/sched_process_fork/enable +( echo "forked") +echo 'snapshot:1' > events/sched/sched_process_fork/trigger +( echo "forked") +grep sched_process_fork snapshot > /dev/null || \ + fail "snapshot trigger on sched_process_fork did not work" + +reset_trigger +echo 0 > snapshot +echo 0 > events/sched/sched_process_fork/enable + +echo "Test snapshot semantic errors" + +! echo "snapshot+1" > events/sched/sched_process_fork/trigger +echo "snapshot" > events/sched/sched_process_fork/trigger +! echo "snapshot" > events/sched/sched_process_fork/trigger + +do_reset + +exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-stacktrace.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-stacktrace.tc new file mode 100644 index 000000000000..9fa23b085def --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-stacktrace.tc @@ -0,0 +1,53 @@ +#!/bin/sh +# description: event trigger - test stacktrace-trigger + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit $FAIL +} + +if [ ! -f set_event -o ! -d events/sched ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f events/sched/sched_process_fork/trigger ]; then + echo "event trigger is not supported" + exit_unsupported +fi + +reset_tracer +do_reset + +FEATURE=`grep stacktrace events/sched/sched_process_fork/trigger` +if [ -z "$FEATURE" ]; then + echo "stacktrace trigger is not supported" + exit_unsupported +fi + +echo "Test stacktrace tigger" +echo 0 > trace +echo 0 > options/stacktrace +echo 'stacktrace' > events/sched/sched_process_fork/trigger +( echo "forked") +grep "" trace > /dev/null || \ + fail "stacktrace trigger on sched_process_fork did not work" + +reset_trigger + +echo "Test stacktrace semantic errors" + +! echo "stacktrace:foo" > events/sched/sched_process_fork/trigger +echo "stacktrace" > events/sched/sched_process_fork/trigger +! echo "stacktrace" > events/sched/sched_process_fork/trigger + +do_reset + +exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-traceonoff.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-traceonoff.tc new file mode 100644 index 000000000000..87648e5f987c --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-traceonoff.tc @@ -0,0 +1,58 @@ +#!/bin/sh +# description: event trigger - test traceon/off trigger + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit $FAIL +} + +if [ ! -f set_event -o ! -d events/sched ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f events/sched/sched_process_fork/trigger ]; then + echo "event trigger is not supported" + exit_unsupported +fi + +reset_tracer +do_reset + +echo "Test traceoff trigger" +echo 1 > tracing_on +echo 'traceoff' > events/sched/sched_process_fork/trigger +( echo "forked") +if [ `cat tracing_on` -ne 0 ]; then + fail "traceoff trigger on sched_process_fork did not work" +fi + +reset_trigger + +echo "Test traceon trigger" +echo 0 > tracing_on +echo 'traceon' > events/sched/sched_process_fork/trigger +( echo "forked") +if [ `cat tracing_on` -ne 1 ]; then + fail "traceoff trigger on sched_process_fork did not work" +fi + +reset_trigger + +echo "Test semantic error for traceoff/on trigger" +! echo 'traceoff:badparam' > events/sched/sched_process_fork/trigger +! echo 'traceoff+0' > events/sched/sched_process_fork/trigger +echo 'traceon' > events/sched/sched_process_fork/trigger +! echo 'traceon' > events/sched/sched_process_fork/trigger +! echo 'traceoff' > events/sched/sched_process_fork/trigger + +do_reset + +exit 0 From 76929ab51f0ee398bcf72286c4b377051f07a31b Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 3 Mar 2016 12:55:01 -0600 Subject: [PATCH 27/45] kselftests/ftrace: Add hist trigger testcases Add the hist trigger testcases for ftracetest. This checks the basic histogram trigger behaviors like as; - Histogram trigger itself - Histogram with string key - Histogram with compound keys - Histogram with sort key - Histogram trigger modifiers (execname, hex, syscall) - Multiple histograms on an event - Named histogram - Named histogram on multi events Here is the test result. ---- # ./ftracetest test.d/trigger/*hist*.tc === Ftrace unit tests === [1] event trigger - test histogram modifiers [PASS] [2] event trigger - test histogram trigger [PASS] [3] event trigger - test multiple histogram triggers [PASS] # of passed: 3 # of failed: 0 # of unresolved: 0 # of untested: 0 # of unsupported: 0 # of xfailed: 0 # of undefined(test bug): 0 ---- Link: http://lkml.kernel.org/r/17cb3a3d9eeadc3282645147905455a298e7fbeb.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Masami Hiramatsu Cc: Ingo Molnar Cc: Shuah Khan Cc: Namhyung Kim Cc: Tom Zanussi Signed-off-by: Tom Zanussi [Tom Zanussi: Change multihist test from truncate ('>') to append ('>>')] Reviewed-by: Namhyung Kim Signed-off-by: Steven Rostedt --- .../ftrace/test.d/trigger/trigger-hist-mod.tc | 65 +++++++++++++++ .../ftrace/test.d/trigger/trigger-hist.tc | 83 +++++++++++++++++++ .../test.d/trigger/trigger-multihist.tc | 73 ++++++++++++++++ 3 files changed, 221 insertions(+) create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-hist.tc create mode 100644 tools/testing/selftests/ftrace/test.d/trigger/trigger-multihist.tc diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc new file mode 100644 index 000000000000..57e350a0bcca --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc @@ -0,0 +1,65 @@ +#!/bin/sh +# description: event trigger - test histogram modifiers + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit $FAIL +} + +if [ ! -f set_event -o ! -d events/sched ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f events/sched/sched_process_fork/trigger ]; then + echo "event trigger is not supported" + exit_unsupported +fi + +reset_tracer +do_reset + +FEATURE=`grep hist events/sched/sched_process_fork/trigger` +if [ -z "$FEATURE" ]; then + echo "hist trigger is not supported" + exit_unsupported +fi + +echo "Test histogram with execname modifier" + +echo 'hist:keys=common_pid.execname' > events/sched/sched_process_fork/trigger +for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done +COMM=`cat /proc/$$/comm` +grep "common_pid: $COMM" events/sched/sched_process_fork/hist > /dev/null || \ + fail "execname modifier on sched_process_fork did not work" + +reset_trigger + +echo "Test histogram with hex modifier" + +echo 'hist:keys=parent_pid.hex' > events/sched/sched_process_fork/trigger +for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done +# Note that $$ is the parent pid. $PID is current PID. +HEX=`printf %x $PID` +grep "parent_pid: $HEX" events/sched/sched_process_fork/hist > /dev/null || \ + fail "hex modifier on sched_process_fork did not work" + +reset_trigger + +echo "Test histogram with syscall modifier" + +echo 'hist:keys=id.syscall' > events/raw_syscalls/sys_exit/trigger +for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done +grep "id: sys_" events/raw_syscalls/sys_exit/hist > /dev/null || \ + fail "syscall modifier on raw_syscalls/sys_exit did not work" + +do_reset + +exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist.tc new file mode 100644 index 000000000000..b2902d42a537 --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist.tc @@ -0,0 +1,83 @@ +#!/bin/sh +# description: event trigger - test histogram trigger + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit $FAIL +} + +if [ ! -f set_event -o ! -d events/sched ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f events/sched/sched_process_fork/trigger ]; then + echo "event trigger is not supported" + exit_unsupported +fi + +reset_tracer +do_reset + +FEATURE=`grep hist events/sched/sched_process_fork/trigger` +if [ -z "$FEATURE" ]; then + echo "hist trigger is not supported" + exit_unsupported +fi + +echo "Test histogram basic tigger" + +echo 'hist:keys=parent_pid:vals=child_pid' > events/sched/sched_process_fork/trigger +for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done +grep parent_pid events/sched/sched_process_fork/hist > /dev/null || \ + fail "hist trigger on sched_process_fork did not work" +grep child events/sched/sched_process_fork/hist > /dev/null || \ + fail "hist trigger on sched_process_fork did not work" + +reset_trigger + +echo "Test histogram with compound keys" + +echo 'hist:keys=parent_pid,child_pid' > events/sched/sched_process_fork/trigger +for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done +grep '^{ parent_pid:.*, child_pid:.*}' events/sched/sched_process_fork/hist > /dev/null || \ + fail "compound keys on sched_process_fork did not work" + +reset_trigger + +echo "Test histogram with string key" + +echo 'hist:keys=parent_comm' > events/sched/sched_process_fork/trigger +for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done +COMM=`cat /proc/$$/comm` +grep "parent_comm: $COMM" events/sched/sched_process_fork/hist > /dev/null || \ + fail "string key on sched_process_fork did not work" + +reset_trigger + +echo "Test histogram with sort key" + +echo 'hist:keys=parent_pid,child_pid:sort=child_pid.ascending' > events/sched/sched_process_fork/trigger +for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done + +check_inc() { + while [ $# -gt 1 ]; do + [ $1 -gt $2 ] && return 1 + shift 1 + done + return 0 +} +check_inc `grep -o "child_pid:[[:space:]]*[[:digit:]]*" \ + events/sched/sched_process_fork/hist | cut -d: -f2 ` || + fail "sort param on sched_process_fork did not work" + +do_reset + +exit 0 diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-multihist.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-multihist.tc new file mode 100644 index 000000000000..03c4a46561fc --- /dev/null +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-multihist.tc @@ -0,0 +1,73 @@ +#!/bin/sh +# description: event trigger - test multiple histogram triggers + +do_reset() { + reset_trigger + echo > set_event + clear_trace +} + +fail() { #msg + do_reset + echo $1 + exit $FAIL +} + +if [ ! -f set_event -o ! -d events/sched ]; then + echo "event tracing is not supported" + exit_unsupported +fi + +if [ ! -f events/sched/sched_process_fork/trigger ]; then + echo "event trigger is not supported" + exit_unsupported +fi + +reset_tracer +do_reset + +FEATURE=`grep hist events/sched/sched_process_fork/trigger` +if [ -z "$FEATURE" ]; then + echo "hist trigger is not supported" + exit_unsupported +fi + +reset_trigger + +echo "Test histogram multiple tiggers" + +echo 'hist:keys=parent_pid:vals=child_pid' > events/sched/sched_process_fork/trigger +echo 'hist:keys=parent_comm:vals=child_pid' >> events/sched/sched_process_fork/trigger +for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done +grep parent_pid events/sched/sched_process_fork/hist > /dev/null || \ + fail "hist trigger on sched_process_fork did not work" +grep child events/sched/sched_process_fork/hist > /dev/null || \ + fail "hist trigger on sched_process_fork did not work" +COMM=`cat /proc/$$/comm` +grep "parent_comm: $COMM" events/sched/sched_process_fork/hist > /dev/null || \ + fail "string key on sched_process_fork did not work" + +reset_trigger + +echo "Test histogram with its name" + +echo 'hist:name=test_hist:keys=common_pid' > events/sched/sched_process_fork/trigger +for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done +grep test_hist events/sched/sched_process_fork/hist > /dev/null || \ + fail "named event on sched_process_fork did not work" + +echo "Test same named histogram on different events" + +echo 'hist:name=test_hist:keys=common_pid' > events/sched/sched_process_exit/trigger +for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done +grep test_hist events/sched/sched_process_exit/hist > /dev/null || \ + fail "named event on sched_process_fork did not work" + +diffs=`diff events/sched/sched_process_exit/hist events/sched/sched_process_fork/hist | wc -l` +test $diffs -eq 0 || fail "Same name histograms are not same" + +reset_trigger + +do_reset + +exit 0 From 4b94f5b7b4a5ffd885609bd033af2ecca0c9cc54 Mon Sep 17 00:00:00 2001 From: Namhyung Kim Date: Thu, 3 Mar 2016 12:55:02 -0600 Subject: [PATCH 28/45] tracing: Add hist trigger 'log2' modifier Allow users to have numeric fields displayed as log2 values in case value range is very wide by appending '.log2' to field names. For example, # echo 'hist:key=bytes_req' > kmalloc/trigger # cat kmalloc/hist { bytes_req: 504 } hitcount: 1 { bytes_req: 11 } hitcount: 1 { bytes_req: 104 } hitcount: 1 { bytes_req: 48 } hitcount: 1 { bytes_req: 2048 } hitcount: 1 { bytes_req: 4096 } hitcount: 1 { bytes_req: 240 } hitcount: 1 { bytes_req: 392 } hitcount: 1 { bytes_req: 13 } hitcount: 1 { bytes_req: 28 } hitcount: 1 { bytes_req: 12 } hitcount: 1 { bytes_req: 64 } hitcount: 2 { bytes_req: 128 } hitcount: 2 { bytes_req: 32 } hitcount: 2 { bytes_req: 8 } hitcount: 11 { bytes_req: 10 } hitcount: 13 { bytes_req: 24 } hitcount: 25 { bytes_req: 160 } hitcount: 29 { bytes_req: 16 } hitcount: 33 { bytes_req: 80 } hitcount: 36 When using '.log2' modifier, the output looks like: # echo 'hist:key=bytes_req.log2' > kmalloc/trigger # cat kmalloc/hist { bytes_req: ~ 2^12 } hitcount: 1 { bytes_req: ~ 2^11 } hitcount: 1 { bytes_req: ~ 2^9 } hitcount: 2 { bytes_req: ~ 2^6 } hitcount: 3 { bytes_req: ~ 2^3 } hitcount: 13 { bytes_req: ~ 2^5 } hitcount: 19 { bytes_req: ~ 2^8 } hitcount: 49 { bytes_req: ~ 2^7 } hitcount: 57 { bytes_req: ~ 2^4 } hitcount: 74 Link: http://lkml.kernel.org/r/7ff396b246c6a881f46b979735fddf05a0d6c71a.1457029949.git.tom.zanussi@linux.intel.com Cc: Tom Zanussi Cc: Masami Hiramatsu Signed-off-by: Namhyung Kim Reviewed-by: Masami Hiramatsu Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 1 + kernel/trace/trace_events_hist.c | 20 ++++++++++++++++++++ 2 files changed, 21 insertions(+) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 4e342d354c12..988a35263fdd 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3872,6 +3872,7 @@ static const char readme_msg[] = "\t .sym-offset display an address as a symbol and offset\n" "\t .execname display a common_pid as a program name\n" "\t .syscall display a syscall id as a syscall name\n\n" + "\t .log2 display log2 value rather than raw number\n\n" "\t The 'pause' parameter can be used to pause an existing hist\n" "\t trigger or to start a hist trigger but not log any events\n" "\t until told to do so. 'continue' can be used to start or\n" diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index bdea5603cbde..23df38aab503 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -68,6 +68,13 @@ static u64 hist_field_pstring(struct hist_field *hist_field, void *event) return (u64)(unsigned long)*addr; } +static u64 hist_field_log2(struct hist_field *hist_field, void *event) +{ + u64 val = *(u64 *)(event + hist_field->field->offset); + + return (u64) ilog2(roundup_pow_of_two(val)); +} + #define DEFINE_HIST_FIELD_FN(type) \ static u64 hist_field_##type(struct hist_field *hist_field, void *event)\ { \ @@ -111,6 +118,7 @@ enum hist_field_flags { HIST_FIELD_FL_EXECNAME = 64, HIST_FIELD_FL_SYSCALL = 128, HIST_FIELD_FL_STACKTRACE = 256, + HIST_FIELD_FL_LOG2 = 512, }; struct hist_trigger_attrs { @@ -358,6 +366,11 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, goto out; } + if (flags & HIST_FIELD_FL_LOG2) { + hist_field->fn = hist_field_log2; + goto out; + } + if (is_string_field(field)) { flags |= HIST_FIELD_FL_STRING; @@ -522,6 +535,8 @@ static int create_key_field(struct hist_trigger_data *hist_data, flags |= HIST_FIELD_FL_EXECNAME; else if (strcmp(field_str, "syscall") == 0) flags |= HIST_FIELD_FL_SYSCALL; + else if (strcmp(field_str, "log2") == 0) + flags |= HIST_FIELD_FL_LOG2; else { ret = -EINVAL; goto out; @@ -980,6 +995,9 @@ hist_trigger_entry_print(struct seq_file *m, key + key_field->offset, HIST_STACKTRACE_DEPTH); multiline = true; + } else if (key_field->flags & HIST_FIELD_FL_LOG2) { + seq_printf(m, "%s: ~ 2^%-2llu", key_field->field->name, + *(u64 *)(key + key_field->offset)); } else if (key_field->flags & HIST_FIELD_FL_STRING) { seq_printf(m, "%s: %-50s", key_field->field->name, (char *)(key + key_field->offset)); @@ -1112,6 +1130,8 @@ static const char *get_hist_field_flags(struct hist_field *hist_field) flags_str = "execname"; else if (hist_field->flags & HIST_FIELD_FL_SYSCALL) flags_str = "syscall"; + else if (hist_field->flags & HIST_FIELD_FL_LOG2) + flags_str = "log2"; return flags_str; } From 93c5f671f25cb7a73492b7a96b426c4fb1efa715 Mon Sep 17 00:00:00 2001 From: Masami Hiramatsu Date: Thu, 3 Mar 2016 12:55:03 -0600 Subject: [PATCH 29/45] kselftests/ftrace: Add a test for log2 modifier of hist trigger Add a test for log2 modifier of hist trigger in hist_mod.tc. Here is the test result. ---- # ./ftracetest test.d/trigger/trigger-hist-mod.tc === Ftrace unit tests === [1] event trigger - test histogram modifiers [PASS] # of passed: 1 # of failed: 0 # of unresolved: 0 # of untested: 0 # of unsupported: 0 # of xfailed: 0 # of undefined(test bug): 0 ---- Link: http://lkml.kernel.org/r/3f1ab735c06a50b1b40d3e96b8b6a3e5ea62fd86.1457029949.git.tom.zanussi@linux.intel.com Signed-off-by: Masami Hiramatsu Cc: Ingo Molnar Cc: Shuah Khan Cc: Namhyung Kim Cc: Tom Zanussi Tested-by: Tom Zanussi Signed-off-by: Steven Rostedt --- .../ftrace/test.d/trigger/trigger-hist-mod.tc | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc index 57e350a0bcca..c2b61c4fda11 100644 --- a/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc +++ b/tools/testing/selftests/ftrace/test.d/trigger/trigger-hist-mod.tc @@ -60,6 +60,16 @@ for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done grep "id: sys_" events/raw_syscalls/sys_exit/hist > /dev/null || \ fail "syscall modifier on raw_syscalls/sys_exit did not work" + +reset_trigger + +echo "Test histgram with log2 modifier" + +echo 'hist:keys=bytes_req.log2' > events/kmem/kmalloc/trigger +for i in `seq 1 10` ; do ( echo "forked" > /dev/null); done +grep 'bytes_req: ~ 2^[0-9]*' events/kmem/kmalloc/hist > /dev/null || \ + fail "log2 modifier on kmem/kmalloc did not work" + do_reset exit 0 From d50c744ecde7ee3ba4d7ffb0e1c55e7a2f6bbc8e Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 8 Mar 2016 17:17:15 -0500 Subject: [PATCH 30/45] tracing: Fix unsigned comparison to zero in hist trigger code Fengguang Wu's bot found two comparisons of unsigned integers to zero. These were real bugs, as it would miss error conditions returned to zero. trace_events_hist.c:426:6-9: WARNING: Unsigned expression compared with zero: idx < 0 trace_events_hist.c:568:5-14: WARNING: Unsigned expression compared with zero: n_entries < 0 Reported-by: kbuild test robot Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_hist.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index 23df38aab503..f98b6b3a2804 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -734,7 +734,7 @@ static int create_tracing_map_fields(struct hist_trigger_data *hist_data) struct tracing_map *map = hist_data->map; struct ftrace_event_field *field; struct hist_field *hist_field; - unsigned int i, idx; + int i, idx; for_each_hist_field(i, hist_data) { hist_field = hist_data->fields[i]; @@ -1036,7 +1036,7 @@ static int print_entries(struct seq_file *m, { struct tracing_map_sort_entry **sort_entries = NULL; struct tracing_map *map = hist_data->map; - unsigned int i, n_entries; + int i, n_entries; n_entries = tracing_map_sort_entries(map, hist_data->sort_keys, hist_data->n_sort_keys, From 205506228b69be4efbb3809957a69420f26a8d9f Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Mon, 25 Apr 2016 22:40:12 -0400 Subject: [PATCH 31/45] tracing: Do not inherit event-fork option for instances As the event-fork option requires doing work when enabled and disabled, it can not be passed down to created instances. The instance must clear this flag when it is created, and must clear it when its removed. As more options may be created with this need, a macro ZEROED_TRACE_FLAGS is created that holds the flags that must not be inherited by the top level instance, and must be cleared on removal of instances. Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 988a35263fdd..5e3ad3481e4b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -253,6 +253,9 @@ unsigned long long ns2usecs(cycle_t nsec) #define TOP_LEVEL_TRACE_FLAGS (TRACE_ITER_PRINTK | \ TRACE_ITER_PRINTK_MSGONLY | TRACE_ITER_RECORD_CMD) +/* trace_flags that are default zero for instances */ +#define ZEROED_TRACE_FLAGS \ + TRACE_ITER_EVENT_FORK /* * The global_trace is the descriptor that holds the tracing @@ -6710,7 +6713,7 @@ static int instance_mkdir(const char *name) if (!alloc_cpumask_var(&tr->tracing_cpumask, GFP_KERNEL)) goto out_free_tr; - tr->trace_flags = global_trace.trace_flags; + tr->trace_flags = global_trace.trace_flags & ~ZEROED_TRACE_FLAGS; cpumask_copy(tr->tracing_cpumask, cpu_all_mask); @@ -6784,6 +6787,12 @@ static int instance_rmdir(const char *name) list_del(&tr->list); + /* Disable all the flags that were enabled coming in */ + for (i = 0; i < TRACE_FLAGS_MAX_SIZE; i++) { + if ((1 << i) & ZEROED_TRACE_FLAGS) + set_tracer_flag(tr, 1 << i, 0); + } + tracing_set_nop(tr); event_trace_del_tracer(tr); ftrace_destroy_function_files(tr); From 4812952f9c94f67b3cc78ad0a6482bf182aa5a44 Mon Sep 17 00:00:00 2001 From: Dan Carpenter Date: Sat, 23 Apr 2016 13:23:47 +0300 Subject: [PATCH 32/45] tracing: checking for NULL instead of IS_ERR() tracing_map_elt_alloc() returns ERR_PTRs on error, never NULL. Fixes: 08d43a5fa063 ('tracing: Add lock-free tracing_map') Link: http://lkml.kernel.org/r/20160423102347.GA11136@mwanda Acked-by: Tom Zanussi Signed-off-by: Dan Carpenter Signed-off-by: Steven Rostedt --- kernel/trace/tracing_map.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c index e0f172932eca..e7dfc5eec669 100644 --- a/kernel/trace/tracing_map.c +++ b/kernel/trace/tracing_map.c @@ -814,7 +814,7 @@ static struct tracing_map_elt *copy_elt(struct tracing_map_elt *elt) unsigned int i; dup_elt = tracing_map_elt_alloc(elt->map); - if (!dup_elt) + if (IS_ERR(dup_elt)) return NULL; if (elt->map->ops && elt->map->ops->elt_copy) From 432480c58219eff32904b879eb3fcc1d268a3b06 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Mon, 25 Apr 2016 14:01:27 -0500 Subject: [PATCH 33/45] tracing: Add check for NULL event field when creating hist field Smatch flagged create_hist_field() as possibly being able to dereference a NULL pointer, although the current code exits in all cases where the event field could be NULL, so it's not actually a problem. Still, to prevent future changes to the code from overlooking new cases, make the NULL pointer check explicit and warn once in that case. Link: http://lkml.kernel.org/r/cfbc003f534a3e441b4313272fd412310aba6336.1461610073.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- kernel/trace/trace_events_hist.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/kernel/trace/trace_events_hist.c b/kernel/trace/trace_events_hist.c index f98b6b3a2804..0c05b8a99806 100644 --- a/kernel/trace/trace_events_hist.c +++ b/kernel/trace/trace_events_hist.c @@ -371,6 +371,9 @@ static struct hist_field *create_hist_field(struct ftrace_event_field *field, goto out; } + if (WARN_ON_ONCE(!field)) + goto out; + if (is_string_field(field)) { flags |= HIST_FIELD_FL_STRING; From 6e4cf657defa8fb06dbf9ed91adb78414758f259 Mon Sep 17 00:00:00 2001 From: Tom Zanussi Date: Mon, 25 Apr 2016 14:01:28 -0500 Subject: [PATCH 34/45] tracing: Handle tracing_map_alloc_elts() error path correctly If tracing_map_elt_alloc() fails, it will return ERR_PTR() instead of NULL, so change the check to IS_ERROR(). We also need to set the failed entry in the map->elts array to NULL instead of ERR_PTR() so tracing_map_free_elts() doesn't try freeing an ERR_PTR(). tracing_map_free_elts() should also zero out what it frees so a reentrant call won't find previously freed elements. Link: http://lkml.kernel.org/r/f29d03b00bce3aac8cf151a8a30e6c83e5fee66d.1461610073.git.tom.zanussi@linux.intel.com Signed-off-by: Tom Zanussi Signed-off-by: Steven Rostedt --- kernel/trace/tracing_map.c | 8 ++++++-- 1 file changed, 6 insertions(+), 2 deletions(-) diff --git a/kernel/trace/tracing_map.c b/kernel/trace/tracing_map.c index e7dfc5eec669..0a689bbb78ef 100644 --- a/kernel/trace/tracing_map.c +++ b/kernel/trace/tracing_map.c @@ -366,10 +366,13 @@ static void tracing_map_free_elts(struct tracing_map *map) if (!map->elts) return; - for (i = 0; i < map->max_elts; i++) + for (i = 0; i < map->max_elts; i++) { tracing_map_elt_free(*(TRACING_MAP_ELT(map->elts, i))); + *(TRACING_MAP_ELT(map->elts, i)) = NULL; + } tracing_map_array_free(map->elts); + map->elts = NULL; } static int tracing_map_alloc_elts(struct tracing_map *map) @@ -383,7 +386,8 @@ static int tracing_map_alloc_elts(struct tracing_map *map) for (i = 0; i < map->max_elts; i++) { *(TRACING_MAP_ELT(map->elts, i)) = tracing_map_elt_alloc(map); - if (!(*(TRACING_MAP_ELT(map->elts, i)))) { + if (IS_ERR(*(TRACING_MAP_ELT(map->elts, i)))) { + *(TRACING_MAP_ELT(map->elts, i)) = NULL; tracing_map_free_elts(map); return -ENOMEM; From 4afe6495e5cb3c352d95f07512cbb227e607e2ce Mon Sep 17 00:00:00 2001 From: Wang Xiaoqiang Date: Mon, 18 Apr 2016 15:23:29 +0800 Subject: [PATCH 35/45] tracing: Don't use the address of the buffer array name in copy_from_user With the following code snippet: ... char buf[64]; ... if (copy_from_user(&buf, ubuf, cnt)) ... Even though the value of "&buf" equals "buf", but there is no need to get the address of the "buf" again. Use "buf" instead of "&buf". Link: http://lkml.kernel.org/r/20160418152329.18b72bea@debian Signed-off-by: Wang Xiaoqiang Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 5e3ad3481e4b..46028d47d252 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -3664,7 +3664,7 @@ tracing_trace_options_write(struct file *filp, const char __user *ubuf, if (cnt >= sizeof(buf)) return -EINVAL; - if (copy_from_user(&buf, ubuf, cnt)) + if (copy_from_user(buf, ubuf, cnt)) return -EFAULT; buf[cnt] = 0; @@ -4537,7 +4537,7 @@ tracing_set_trace_write(struct file *filp, const char __user *ubuf, if (cnt > MAX_TRACER_SIZE) cnt = MAX_TRACER_SIZE; - if (copy_from_user(&buf, ubuf, cnt)) + if (copy_from_user(buf, ubuf, cnt)) return -EFAULT; buf[cnt] = 0; @@ -5327,7 +5327,7 @@ static ssize_t tracing_clock_write(struct file *filp, const char __user *ubuf, if (cnt >= sizeof(buf)) return -EINVAL; - if (copy_from_user(&buf, ubuf, cnt)) + if (copy_from_user(buf, ubuf, cnt)) return -EFAULT; buf[cnt] = 0; From dad56ee742a3abbb5d9e8108f8537d412bff3f57 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 26 Apr 2016 21:22:22 -0400 Subject: [PATCH 36/45] tracing: Move event_trigger_unlock_commit{_regs}() to local header The functions event_trigger_unlock_commit() and event_trigger_unlock_commit_regs() are no longer used outside the tracing system. Move them out of the generic headers and into the local one. Along with __event_trigger_test_discard() that is only used by them. Signed-off-by: Steven Rostedt --- include/linux/trace_events.h | 94 ------------------------------------ kernel/trace/trace.h | 94 ++++++++++++++++++++++++++++++++++++ 2 files changed, 94 insertions(+), 94 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 5f89a5b0c7e6..70a181cb3585 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -452,100 +452,6 @@ trace_trigger_soft_disabled(struct trace_event_file *file) return false; } -/* - * Helper function for event_trigger_unlock_commit{_regs}(). - * If there are event triggers attached to this event that requires - * filtering against its fields, then they wil be called as the - * entry already holds the field information of the current event. - * - * It also checks if the event should be discarded or not. - * It is to be discarded if the event is soft disabled and the - * event was only recorded to process triggers, or if the event - * filter is active and this event did not match the filters. - * - * Returns true if the event is discarded, false otherwise. - */ -static inline bool -__event_trigger_test_discard(struct trace_event_file *file, - struct ring_buffer *buffer, - struct ring_buffer_event *event, - void *entry, - enum event_trigger_type *tt) -{ - unsigned long eflags = file->flags; - - if (eflags & EVENT_FILE_FL_TRIGGER_COND) - *tt = event_triggers_call(file, entry); - - if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags)) - ring_buffer_discard_commit(buffer, event); - else if (!filter_check_discard(file, entry, buffer, event)) - return false; - - return true; -} - -/** - * event_trigger_unlock_commit - handle triggers and finish event commit - * @file: The file pointer assoctiated to the event - * @buffer: The ring buffer that the event is being written to - * @event: The event meta data in the ring buffer - * @entry: The event itself - * @irq_flags: The state of the interrupts at the start of the event - * @pc: The state of the preempt count at the start of the event. - * - * This is a helper function to handle triggers that require data - * from the event itself. It also tests the event against filters and - * if the event is soft disabled and should be discarded. - */ -static inline void -event_trigger_unlock_commit(struct trace_event_file *file, - struct ring_buffer *buffer, - struct ring_buffer_event *event, - void *entry, unsigned long irq_flags, int pc) -{ - enum event_trigger_type tt = ETT_NONE; - - if (!__event_trigger_test_discard(file, buffer, event, entry, &tt)) - trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc); - - if (tt) - event_triggers_post_call(file, tt, entry); -} - -/** - * event_trigger_unlock_commit_regs - handle triggers and finish event commit - * @file: The file pointer assoctiated to the event - * @buffer: The ring buffer that the event is being written to - * @event: The event meta data in the ring buffer - * @entry: The event itself - * @irq_flags: The state of the interrupts at the start of the event - * @pc: The state of the preempt count at the start of the event. - * - * This is a helper function to handle triggers that require data - * from the event itself. It also tests the event against filters and - * if the event is soft disabled and should be discarded. - * - * Same as event_trigger_unlock_commit() but calls - * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit(). - */ -static inline void -event_trigger_unlock_commit_regs(struct trace_event_file *file, - struct ring_buffer *buffer, - struct ring_buffer_event *event, - void *entry, unsigned long irq_flags, int pc, - struct pt_regs *regs) -{ - enum event_trigger_type tt = ETT_NONE; - - if (!__event_trigger_test_discard(file, buffer, event, entry, &tt)) - trace_buffer_unlock_commit_regs(file->tr, buffer, event, - irq_flags, pc, regs); - - if (tt) - event_triggers_post_call(file, tt, entry); -} - #ifdef CONFIG_BPF_EVENTS unsigned int trace_call_bpf(struct bpf_prog *prog, void *ctx); #else diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 727a3d28bce5..c0eac7b1e5a6 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1065,6 +1065,100 @@ struct trace_subsystem_dir { int nr_events; }; +/* + * Helper function for event_trigger_unlock_commit{_regs}(). + * If there are event triggers attached to this event that requires + * filtering against its fields, then they wil be called as the + * entry already holds the field information of the current event. + * + * It also checks if the event should be discarded or not. + * It is to be discarded if the event is soft disabled and the + * event was only recorded to process triggers, or if the event + * filter is active and this event did not match the filters. + * + * Returns true if the event is discarded, false otherwise. + */ +static inline bool +__event_trigger_test_discard(struct trace_event_file *file, + struct ring_buffer *buffer, + struct ring_buffer_event *event, + void *entry, + enum event_trigger_type *tt) +{ + unsigned long eflags = file->flags; + + if (eflags & EVENT_FILE_FL_TRIGGER_COND) + *tt = event_triggers_call(file, entry); + + if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags)) + ring_buffer_discard_commit(buffer, event); + else if (!filter_check_discard(file, entry, buffer, event)) + return false; + + return true; +} + +/** + * event_trigger_unlock_commit - handle triggers and finish event commit + * @file: The file pointer assoctiated to the event + * @buffer: The ring buffer that the event is being written to + * @event: The event meta data in the ring buffer + * @entry: The event itself + * @irq_flags: The state of the interrupts at the start of the event + * @pc: The state of the preempt count at the start of the event. + * + * This is a helper function to handle triggers that require data + * from the event itself. It also tests the event against filters and + * if the event is soft disabled and should be discarded. + */ +static inline void +event_trigger_unlock_commit(struct trace_event_file *file, + struct ring_buffer *buffer, + struct ring_buffer_event *event, + void *entry, unsigned long irq_flags, int pc) +{ + enum event_trigger_type tt = ETT_NONE; + + if (!__event_trigger_test_discard(file, buffer, event, entry, &tt)) + trace_buffer_unlock_commit(file->tr, buffer, event, irq_flags, pc); + + if (tt) + event_triggers_post_call(file, tt, entry); +} + +/** + * event_trigger_unlock_commit_regs - handle triggers and finish event commit + * @file: The file pointer assoctiated to the event + * @buffer: The ring buffer that the event is being written to + * @event: The event meta data in the ring buffer + * @entry: The event itself + * @irq_flags: The state of the interrupts at the start of the event + * @pc: The state of the preempt count at the start of the event. + * + * This is a helper function to handle triggers that require data + * from the event itself. It also tests the event against filters and + * if the event is soft disabled and should be discarded. + * + * Same as event_trigger_unlock_commit() but calls + * trace_buffer_unlock_commit_regs() instead of trace_buffer_unlock_commit(). + */ +static inline void +event_trigger_unlock_commit_regs(struct trace_event_file *file, + struct ring_buffer *buffer, + struct ring_buffer_event *event, + void *entry, unsigned long irq_flags, int pc, + struct pt_regs *regs) +{ + enum event_trigger_type tt = ETT_NONE; + + if (!__event_trigger_test_discard(file, buffer, event, entry, &tt)) + trace_buffer_unlock_commit_regs(file->tr, buffer, event, + irq_flags, pc, regs); + + if (tt) + event_triggers_post_call(file, tt, entry); +} + #define FILTER_PRED_INVALID ((unsigned short)-1) #define FILTER_PRED_IS_RIGHT (1 << 15) #define FILTER_PRED_FOLD (1 << 15) From 65da9a0a3bf2202c2432f42d41eb908f2fa30579 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 27 Apr 2016 10:13:46 -0400 Subject: [PATCH 37/45] tracing: Make filter_check_discard() local Nothing outside of the tracing directory calls filter_check_discard() or check_filter_check_discard(). They should not be called by modules. Move their prototypes into the local tracing header and remove their EXPORT_SYMBOL() macros. Signed-off-by: Steven Rostedt --- include/linux/trace_events.h | 6 ------ kernel/trace/trace.c | 2 -- kernel/trace/trace.h | 6 ++++++ 3 files changed, 6 insertions(+), 8 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 70a181cb3585..bb383af35cc7 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -413,12 +413,6 @@ enum event_trigger_type { extern int filter_match_preds(struct event_filter *filter, void *rec); -extern int filter_check_discard(struct trace_event_file *file, void *rec, - struct ring_buffer *buffer, - struct ring_buffer_event *event); -extern int call_filter_check_discard(struct trace_event_call *call, void *rec, - struct ring_buffer *buffer, - struct ring_buffer_event *event); extern enum event_trigger_type event_triggers_call(struct trace_event_file *file, void *rec); extern void event_triggers_post_call(struct trace_event_file *file, diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 46028d47d252..02f5a5f51d49 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -318,7 +318,6 @@ int filter_check_discard(struct trace_event_file *file, void *rec, return 0; } -EXPORT_SYMBOL_GPL(filter_check_discard); int call_filter_check_discard(struct trace_event_call *call, void *rec, struct ring_buffer *buffer, @@ -332,7 +331,6 @@ int call_filter_check_discard(struct trace_event_call *call, void *rec, return 0; } -EXPORT_SYMBOL_GPL(call_filter_check_discard); static cycle_t buffer_ftrace_now(struct trace_buffer *buf, int cpu) { diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index c0eac7b1e5a6..ee8691c66bfe 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1065,6 +1065,12 @@ struct trace_subsystem_dir { int nr_events; }; +extern int filter_check_discard(struct trace_event_file *file, void *rec, + struct ring_buffer *buffer, + struct ring_buffer_event *event); +extern int call_filter_check_discard(struct trace_event_call *call, void *rec, + struct ring_buffer *buffer, + struct ring_buffer_event *event); /* * Helper function for event_trigger_unlock_commit{_regs}(). * If there are event triggers attached to this event that requires From 9cbb1506ab2db987c160e7fc50665bf47b5b6fa1 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Wed, 27 Apr 2016 11:09:42 -0400 Subject: [PATCH 38/45] tracing: Fold filter_check_discard() into its only user The function filter_check_discard() is small and only called by one user, its code can be folded into that one caller and make the code a bit less comlplex. Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 13 ------------- kernel/trace/trace.h | 13 ++++++------- 2 files changed, 6 insertions(+), 20 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 02f5a5f51d49..1ba54e241c8d 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -306,19 +306,6 @@ void trace_array_put(struct trace_array *this_tr) mutex_unlock(&trace_types_lock); } -int filter_check_discard(struct trace_event_file *file, void *rec, - struct ring_buffer *buffer, - struct ring_buffer_event *event) -{ - if (unlikely(file->flags & EVENT_FILE_FL_FILTERED) && - !filter_match_preds(file->filter, rec)) { - ring_buffer_discard_commit(buffer, event); - return 1; - } - - return 0; -} - int call_filter_check_discard(struct trace_event_call *call, void *rec, struct ring_buffer *buffer, struct ring_buffer_event *event) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index ee8691c66bfe..0862e7559548 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1065,9 +1065,6 @@ struct trace_subsystem_dir { int nr_events; }; -extern int filter_check_discard(struct trace_event_file *file, void *rec, - struct ring_buffer *buffer, - struct ring_buffer_event *event); extern int call_filter_check_discard(struct trace_event_call *call, void *rec, struct ring_buffer *buffer, struct ring_buffer_event *event); @@ -1096,12 +1093,14 @@ __event_trigger_test_discard(struct trace_event_file *file, if (eflags & EVENT_FILE_FL_TRIGGER_COND) *tt = event_triggers_call(file, entry); - if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags)) + if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) || + (unlikely(file->flags & EVENT_FILE_FL_FILTERED) && + !filter_match_preds(file->filter, entry))) { ring_buffer_discard_commit(buffer, event); - else if (!filter_check_discard(file, entry, buffer, event)) - return false; + return true; + } - return true; + return false; } /** From fa66ddb870ca022342fe6d1312ef76d2f7233a1d Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Thu, 28 Apr 2016 12:04:13 -0400 Subject: [PATCH 39/45] tracing: Move trace_buffer_unlock_commit{_regs}() to local header The functions trace_buffer_unlock_commit() and the _regs() version are only used within the kernel/trace directory. Move them to the local header and remove the export as well. Signed-off-by: Steven Rostedt --- include/linux/trace_events.h | 9 --------- kernel/trace/trace.c | 2 -- kernel/trace/trace.h | 10 ++++++++++ 3 files changed, 10 insertions(+), 11 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index bb383af35cc7..48cc5e19c5f5 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -158,15 +158,6 @@ struct ring_buffer_event * trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer, int type, unsigned long len, unsigned long flags, int pc); -void trace_buffer_unlock_commit(struct trace_array *tr, - struct ring_buffer *buffer, - struct ring_buffer_event *event, - unsigned long flags, int pc); -void trace_buffer_unlock_commit_regs(struct trace_array *tr, - struct ring_buffer *buffer, - struct ring_buffer_event *event, - unsigned long flags, int pc, - struct pt_regs *regs); void trace_current_buffer_discard_commit(struct ring_buffer *buffer, struct ring_buffer_event *event); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 1ba54e241c8d..94e7e4d11b79 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1696,7 +1696,6 @@ void trace_buffer_unlock_commit(struct trace_array *tr, ftrace_trace_stack(tr, buffer, flags, 6, pc, NULL); ftrace_trace_userstack(buffer, flags, pc); } -EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit); static struct ring_buffer *temp_buffer; @@ -1748,7 +1747,6 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr, ftrace_trace_stack(tr, buffer, flags, 0, pc, regs); ftrace_trace_userstack(buffer, flags, pc); } -EXPORT_SYMBOL_GPL(trace_buffer_unlock_commit_regs); void trace_current_buffer_discard_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 0862e7559548..bd5ae56dec7a 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1068,6 +1068,16 @@ struct trace_subsystem_dir { extern int call_filter_check_discard(struct trace_event_call *call, void *rec, struct ring_buffer *buffer, struct ring_buffer_event *event); + +void trace_buffer_unlock_commit(struct trace_array *tr, + struct ring_buffer *buffer, + struct ring_buffer_event *event, + unsigned long flags, int pc); +void trace_buffer_unlock_commit_regs(struct trace_array *tr, + struct ring_buffer *buffer, + struct ring_buffer_event *event, + unsigned long flags, int pc, + struct pt_regs *regs); /* * Helper function for event_trigger_unlock_commit{_regs}(). * If there are event triggers attached to this event that requires From a9fe48dcde88fd48e210e4280f19cb9300ec9112 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Fri, 29 Apr 2016 16:12:39 -0400 Subject: [PATCH 40/45] tracing: Remove unused function trace_current_buffer_discard_commit() The function trace_current_buffer_discard_commit() has no callers, remove it. Signed-off-by: Steven Rostedt --- include/linux/trace_events.h | 2 -- kernel/trace/trace.c | 8 -------- 2 files changed, 10 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 48cc5e19c5f5..356c39b3abbb 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -158,8 +158,6 @@ struct ring_buffer_event * trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer, int type, unsigned long len, unsigned long flags, int pc); -void trace_current_buffer_discard_commit(struct ring_buffer *buffer, - struct ring_buffer_event *event); void tracing_record_cmdline(struct task_struct *tsk); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 94e7e4d11b79..e5bdb9accf52 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1734,7 +1734,6 @@ trace_current_buffer_lock_reserve(struct ring_buffer **current_rb, return trace_buffer_lock_reserve(*current_rb, type, len, flags, pc); } -EXPORT_SYMBOL_GPL(trace_current_buffer_lock_reserve); void trace_buffer_unlock_commit_regs(struct trace_array *tr, struct ring_buffer *buffer, @@ -1748,13 +1747,6 @@ void trace_buffer_unlock_commit_regs(struct trace_array *tr, ftrace_trace_userstack(buffer, flags, pc); } -void trace_current_buffer_discard_commit(struct ring_buffer *buffer, - struct ring_buffer_event *event) -{ - ring_buffer_discard_commit(buffer, event); -} -EXPORT_SYMBOL_GPL(trace_current_buffer_discard_commit); - void trace_function(struct trace_array *tr, unsigned long ip, unsigned long parent_ip, unsigned long flags, From 33fddff24d05d71f97722cb7deec4964d39d10dc Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Fri, 29 Apr 2016 17:44:01 -0400 Subject: [PATCH 41/45] tracing: Have trace_buffer_unlock_commit() call the _regs version with NULL There's no real difference between trace_buffer_unlock_commit() and trace_buffer_unlock_commit_regs() except that the former passes NULL to ftrace_stack_trace() instead of regs. Have the former be a static inline of the latter which passes NULL for regs. Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 11 ----------- kernel/trace/trace.h | 13 +++++++++---- 2 files changed, 9 insertions(+), 15 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index e5bdb9accf52..41bf14412666 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1686,17 +1686,6 @@ __buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *eve ring_buffer_unlock_commit(buffer, event); } -void trace_buffer_unlock_commit(struct trace_array *tr, - struct ring_buffer *buffer, - struct ring_buffer_event *event, - unsigned long flags, int pc) -{ - __buffer_unlock_commit(buffer, event); - - ftrace_trace_stack(tr, buffer, flags, 6, pc, NULL); - ftrace_trace_userstack(buffer, flags, pc); -} - static struct ring_buffer *temp_buffer; struct ring_buffer_event * diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index bd5ae56dec7a..10156a09103f 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1069,15 +1069,20 @@ extern int call_filter_check_discard(struct trace_event_call *call, void *rec, struct ring_buffer *buffer, struct ring_buffer_event *event); -void trace_buffer_unlock_commit(struct trace_array *tr, - struct ring_buffer *buffer, - struct ring_buffer_event *event, - unsigned long flags, int pc); void trace_buffer_unlock_commit_regs(struct trace_array *tr, struct ring_buffer *buffer, struct ring_buffer_event *event, unsigned long flags, int pc, struct pt_regs *regs); + +static inline void trace_buffer_unlock_commit(struct trace_array *tr, + struct ring_buffer *buffer, + struct ring_buffer_event *event, + unsigned long flags, int pc) +{ + trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL); +} + /* * Helper function for event_trigger_unlock_commit{_regs}(). * If there are event triggers attached to this event that requires From 9b9db275051cd9191e7776c4fd79ccd4318aa2dc Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Fri, 29 Apr 2016 18:10:21 -0400 Subject: [PATCH 42/45] tracing: Remove one use of trace_current_buffer_lock_reserve() The only user of trace_current_buffer_lock_reserve() is in the boot up self tests. Restructure the code a little to have that code use what everything else uses: trace_event_buffer_lock_reserve(). Signed-off-by: Steven Rostedt --- kernel/trace/trace_events.c | 18 ++++++++++-------- 1 file changed, 10 insertions(+), 8 deletions(-) diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index e7cb983ee93c..da1eeb6190e3 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -3392,7 +3392,7 @@ static __init void event_trace_self_tests(void) static DEFINE_PER_CPU(atomic_t, ftrace_test_event_disable); -static struct trace_array *event_tr; +static struct trace_event_file event_trace_file __initdata; static void __init function_test_events_call(unsigned long ip, unsigned long parent_ip, @@ -3416,17 +3416,17 @@ function_test_events_call(unsigned long ip, unsigned long parent_ip, local_save_flags(flags); - event = trace_current_buffer_lock_reserve(&buffer, - TRACE_FN, sizeof(*entry), - flags, pc); + event = trace_event_buffer_lock_reserve(&buffer, &event_trace_file, + TRACE_FN, sizeof(*entry), + flags, pc); if (!event) goto out; entry = ring_buffer_event_data(event); entry->ip = ip; entry->parent_ip = parent_ip; - trace_buffer_unlock_commit(event_tr, buffer, event, flags, pc); - + event_trigger_unlock_commit(&event_trace_file, buffer, event, + entry, flags, pc); out: atomic_dec(&per_cpu(ftrace_test_event_disable, cpu)); preempt_enable_notrace(); @@ -3441,9 +3441,11 @@ static struct ftrace_ops trace_ops __initdata = static __init void event_trace_self_test_with_function(void) { int ret; - event_tr = top_trace_array(); - if (WARN_ON(!event_tr)) + + event_trace_file.tr = top_trace_array(); + if (WARN_ON(!event_trace_file.tr)) return; + ret = register_ftrace_function(&trace_ops); if (WARN_ON(ret < 0)) { pr_info("Failed to enable function tracer for event tests\n"); From 904d1857ad09b43f514897dd42daffe200d1ca50 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Fri, 29 Apr 2016 18:11:54 -0400 Subject: [PATCH 43/45] tracing: Remove unused function trace_current_buffer_lock_reserve() trace_current_buffer_lock_reserve() has no more users. Remove it. Signed-off-by: Steven Rostedt --- include/linux/trace_events.h | 4 ---- kernel/trace/trace.c | 10 ---------- 2 files changed, 14 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 356c39b3abbb..3111a1efdad6 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -154,10 +154,6 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_buffer, struct trace_event_file *trace_file, int type, unsigned long len, unsigned long flags, int pc); -struct ring_buffer_event * -trace_current_buffer_lock_reserve(struct ring_buffer **current_buffer, - int type, unsigned long len, - unsigned long flags, int pc); void tracing_record_cmdline(struct task_struct *tsk); diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index 41bf14412666..c09e8ffadc73 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -1714,16 +1714,6 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb, } EXPORT_SYMBOL_GPL(trace_event_buffer_lock_reserve); -struct ring_buffer_event * -trace_current_buffer_lock_reserve(struct ring_buffer **current_rb, - int type, unsigned long len, - unsigned long flags, int pc) -{ - *current_rb = global_trace.trace_buffer.buffer; - return trace_buffer_lock_reserve(*current_rb, - type, len, flags, pc); -} - void trace_buffer_unlock_commit_regs(struct trace_array *tr, struct ring_buffer *buffer, struct ring_buffer_event *event, From dcb0b5575d24a32f51a3f1003312fb94ed4e214a Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Mon, 2 May 2016 21:30:04 -0400 Subject: [PATCH 44/45] tracing: Remove TRACE_EVENT_FL_USE_CALL_FILTER logic Nothing sets TRACE_EVENT_FL_USE_CALL_FILTER anymore. Remove it. Signed-off-by: Steven Rostedt --- include/linux/trace_events.h | 3 -- kernel/trace/trace_events_filter.c | 71 +++++------------------------- 2 files changed, 10 insertions(+), 64 deletions(-) diff --git a/include/linux/trace_events.h b/include/linux/trace_events.h index 3111a1efdad6..ba6456302e34 100644 --- a/include/linux/trace_events.h +++ b/include/linux/trace_events.h @@ -214,7 +214,6 @@ enum { TRACE_EVENT_FL_NO_SET_FILTER_BIT, TRACE_EVENT_FL_IGNORE_ENABLE_BIT, TRACE_EVENT_FL_WAS_ENABLED_BIT, - TRACE_EVENT_FL_USE_CALL_FILTER_BIT, TRACE_EVENT_FL_TRACEPOINT_BIT, TRACE_EVENT_FL_KPROBE_BIT, TRACE_EVENT_FL_UPROBE_BIT, @@ -229,7 +228,6 @@ enum { * WAS_ENABLED - Set and stays set when an event was ever enabled * (used for module unloading, if a module event is enabled, * it is best to clear the buffers that used it). - * USE_CALL_FILTER - For trace internal events, don't use file filter * TRACEPOINT - Event is a tracepoint * KPROBE - Event is a kprobe * UPROBE - Event is a uprobe @@ -240,7 +238,6 @@ enum { TRACE_EVENT_FL_NO_SET_FILTER = (1 << TRACE_EVENT_FL_NO_SET_FILTER_BIT), TRACE_EVENT_FL_IGNORE_ENABLE = (1 << TRACE_EVENT_FL_IGNORE_ENABLE_BIT), TRACE_EVENT_FL_WAS_ENABLED = (1 << TRACE_EVENT_FL_WAS_ENABLED_BIT), - TRACE_EVENT_FL_USE_CALL_FILTER = (1 << TRACE_EVENT_FL_USE_CALL_FILTER_BIT), TRACE_EVENT_FL_TRACEPOINT = (1 << TRACE_EVENT_FL_TRACEPOINT_BIT), TRACE_EVENT_FL_KPROBE = (1 << TRACE_EVENT_FL_KPROBE_BIT), TRACE_EVENT_FL_UPROBE = (1 << TRACE_EVENT_FL_UPROBE_BIT), diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index b3f5051cd4e9..d1d27bf37a19 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -689,10 +689,7 @@ static void append_filter_err(struct filter_parse_state *ps, static inline struct event_filter *event_filter(struct trace_event_file *file) { - if (file->event_call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) - return file->event_call->filter; - else - return file->filter; + return file->filter; } /* caller must hold event_mutex */ @@ -826,12 +823,7 @@ static void __free_preds(struct event_filter *filter) static void filter_disable(struct trace_event_file *file) { - struct trace_event_call *call = file->event_call; - - if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) - call->flags &= ~TRACE_EVENT_FL_FILTERED; - else - file->flags &= ~EVENT_FILE_FL_FILTERED; + file->flags &= ~EVENT_FILE_FL_FILTERED; } static void __free_filter(struct event_filter *filter) @@ -883,13 +875,8 @@ static int __alloc_preds(struct event_filter *filter, int n_preds) static inline void __remove_filter(struct trace_event_file *file) { - struct trace_event_call *call = file->event_call; - filter_disable(file); - if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) - remove_filter_string(call->filter); - else - remove_filter_string(file->filter); + remove_filter_string(file->filter); } static void filter_free_subsystem_preds(struct trace_subsystem_dir *dir, @@ -906,15 +893,8 @@ static void filter_free_subsystem_preds(struct trace_subsystem_dir *dir, static inline void __free_subsystem_filter(struct trace_event_file *file) { - struct trace_event_call *call = file->event_call; - - if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) { - __free_filter(call->filter); - call->filter = NULL; - } else { - __free_filter(file->filter); - file->filter = NULL; - } + __free_filter(file->filter); + file->filter = NULL; } static void filter_free_subsystem_filters(struct trace_subsystem_dir *dir, @@ -1718,69 +1698,38 @@ static int replace_preds(struct trace_event_call *call, static inline void event_set_filtered_flag(struct trace_event_file *file) { - struct trace_event_call *call = file->event_call; - - if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) - call->flags |= TRACE_EVENT_FL_FILTERED; - else - file->flags |= EVENT_FILE_FL_FILTERED; + file->flags |= EVENT_FILE_FL_FILTERED; } static inline void event_set_filter(struct trace_event_file *file, struct event_filter *filter) { - struct trace_event_call *call = file->event_call; - - if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) - rcu_assign_pointer(call->filter, filter); - else - rcu_assign_pointer(file->filter, filter); + rcu_assign_pointer(file->filter, filter); } static inline void event_clear_filter(struct trace_event_file *file) { - struct trace_event_call *call = file->event_call; - - if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) - RCU_INIT_POINTER(call->filter, NULL); - else - RCU_INIT_POINTER(file->filter, NULL); + RCU_INIT_POINTER(file->filter, NULL); } static inline void event_set_no_set_filter_flag(struct trace_event_file *file) { - struct trace_event_call *call = file->event_call; - - if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) - call->flags |= TRACE_EVENT_FL_NO_SET_FILTER; - else - file->flags |= EVENT_FILE_FL_NO_SET_FILTER; + file->flags |= EVENT_FILE_FL_NO_SET_FILTER; } static inline void event_clear_no_set_filter_flag(struct trace_event_file *file) { - struct trace_event_call *call = file->event_call; - - if (call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) - call->flags &= ~TRACE_EVENT_FL_NO_SET_FILTER; - else - file->flags &= ~EVENT_FILE_FL_NO_SET_FILTER; + file->flags &= ~EVENT_FILE_FL_NO_SET_FILTER; } static inline bool event_no_set_filter_flag(struct trace_event_file *file) { - struct trace_event_call *call = file->event_call; - if (file->flags & EVENT_FILE_FL_NO_SET_FILTER) return true; - if ((call->flags & TRACE_EVENT_FL_USE_CALL_FILTER) && - (call->flags & TRACE_EVENT_FL_NO_SET_FILTER)) - return true; - return false; } From 0fc1b09ff1ff404ddf753f5ffa5cd0adc8fdcdc9 Mon Sep 17 00:00:00 2001 From: "Steven Rostedt (Red Hat)" Date: Tue, 3 May 2016 17:15:43 -0400 Subject: [PATCH 45/45] tracing: Use temp buffer when filtering events Filtering of events requires the data to be written to the ring buffer before it can be decided to filter or not. This is because the parameters of the filter are based on the result that is written to the ring buffer and not on the parameters that are passed into the trace functions. The ftrace ring buffer is optimized for writing into the ring buffer and committing. The discard procedure used when filtering decides the event should be discarded is much more heavy weight. Thus, using a temporary filter when filtering events can speed things up drastically. Without a temp buffer we have: # trace-cmd start -p nop # perf stat -r 10 hackbench 50 0.790706626 seconds time elapsed ( +- 0.71% ) # trace-cmd start -e all # perf stat -r 10 hackbench 50 1.566904059 seconds time elapsed ( +- 0.27% ) # trace-cmd start -e all -f 'common_preempt_count==20' # perf stat -r 10 hackbench 50 1.690598511 seconds time elapsed ( +- 0.19% ) # trace-cmd start -e all -f 'common_preempt_count!=20' # perf stat -r 10 hackbench 50 1.707486364 seconds time elapsed ( +- 0.30% ) The first run above is without any tracing, just to get a based figure. hackbench takes ~0.79 seconds to run on the system. The second run enables tracing all events where nothing is filtered. This increases the time by 100% and hackbench takes 1.57 seconds to run. The third run filters all events where the preempt count will equal "20" (this should never happen) thus all events are discarded. This takes 1.69 seconds to run. This is 10% slower than just committing the events! The last run enables all events and filters where the filter will commit all events, and this takes 1.70 seconds to run. The filtering overhead is approximately 10%. Thus, the discard and commit of an event from the ring buffer may be about the same time. With this patch, the numbers change: # trace-cmd start -p nop # perf stat -r 10 hackbench 50 0.778233033 seconds time elapsed ( +- 0.38% ) # trace-cmd start -e all # perf stat -r 10 hackbench 50 1.582102692 seconds time elapsed ( +- 0.28% ) # trace-cmd start -e all -f 'common_preempt_count==20' # perf stat -r 10 hackbench 50 1.309230710 seconds time elapsed ( +- 0.22% ) # trace-cmd start -e all -f 'common_preempt_count!=20' # perf stat -r 10 hackbench 50 1.786001924 seconds time elapsed ( +- 0.20% ) The first run is again the base with no tracing. The second run is all tracing with no filtering. It is a little slower, but that may be well within the noise. The third run shows that discarding all events only took 1.3 seconds. This is a speed up of 23%! The discard is much faster than even the commit. The one downside is shown in the last run. Events that are not discarded by the filter will take longer to add, this is due to the extra copy of the event. Cc: Alexei Starovoitov Signed-off-by: Steven Rostedt --- kernel/trace/trace.c | 156 +++++++++++++++++++++++++++-- kernel/trace/trace.h | 19 +++- kernel/trace/trace_events.c | 10 ++ kernel/trace/trace_events_filter.c | 10 ++ 4 files changed, 186 insertions(+), 9 deletions(-) diff --git a/kernel/trace/trace.c b/kernel/trace/trace.c index c09e8ffadc73..8a4bd6b68a0b 100644 --- a/kernel/trace/trace.c +++ b/kernel/trace/trace.c @@ -312,7 +312,7 @@ int call_filter_check_discard(struct trace_event_call *call, void *rec, { if (unlikely(call->flags & TRACE_EVENT_FL_FILTERED) && !filter_match_preds(call->filter, rec)) { - ring_buffer_discard_commit(buffer, event); + __trace_event_discard_commit(buffer, event); return 1; } @@ -1660,6 +1660,16 @@ tracing_generic_entry_update(struct trace_entry *entry, unsigned long flags, } EXPORT_SYMBOL_GPL(tracing_generic_entry_update); +static __always_inline void +trace_event_setup(struct ring_buffer_event *event, + int type, unsigned long flags, int pc) +{ + struct trace_entry *ent = ring_buffer_event_data(event); + + tracing_generic_entry_update(ent, flags, pc); + ent->type = type; +} + struct ring_buffer_event * trace_buffer_lock_reserve(struct ring_buffer *buffer, int type, @@ -1669,21 +1679,136 @@ trace_buffer_lock_reserve(struct ring_buffer *buffer, struct ring_buffer_event *event; event = ring_buffer_lock_reserve(buffer, len); - if (event != NULL) { - struct trace_entry *ent = ring_buffer_event_data(event); - - tracing_generic_entry_update(ent, flags, pc); - ent->type = type; - } + if (event != NULL) + trace_event_setup(event, type, flags, pc); return event; } +DEFINE_PER_CPU(struct ring_buffer_event *, trace_buffered_event); +DEFINE_PER_CPU(int, trace_buffered_event_cnt); +static int trace_buffered_event_ref; + +/** + * trace_buffered_event_enable - enable buffering events + * + * When events are being filtered, it is quicker to use a temporary + * buffer to write the event data into if there's a likely chance + * that it will not be committed. The discard of the ring buffer + * is not as fast as committing, and is much slower than copying + * a commit. + * + * When an event is to be filtered, allocate per cpu buffers to + * write the event data into, and if the event is filtered and discarded + * it is simply dropped, otherwise, the entire data is to be committed + * in one shot. + */ +void trace_buffered_event_enable(void) +{ + struct ring_buffer_event *event; + struct page *page; + int cpu; + + WARN_ON_ONCE(!mutex_is_locked(&event_mutex)); + + if (trace_buffered_event_ref++) + return; + + for_each_tracing_cpu(cpu) { + page = alloc_pages_node(cpu_to_node(cpu), + GFP_KERNEL | __GFP_NORETRY, 0); + if (!page) + goto failed; + + event = page_address(page); + memset(event, 0, sizeof(*event)); + + per_cpu(trace_buffered_event, cpu) = event; + + preempt_disable(); + if (cpu == smp_processor_id() && + this_cpu_read(trace_buffered_event) != + per_cpu(trace_buffered_event, cpu)) + WARN_ON_ONCE(1); + preempt_enable(); + } + + return; + failed: + trace_buffered_event_disable(); +} + +static void enable_trace_buffered_event(void *data) +{ + /* Probably not needed, but do it anyway */ + smp_rmb(); + this_cpu_dec(trace_buffered_event_cnt); +} + +static void disable_trace_buffered_event(void *data) +{ + this_cpu_inc(trace_buffered_event_cnt); +} + +/** + * trace_buffered_event_disable - disable buffering events + * + * When a filter is removed, it is faster to not use the buffered + * events, and to commit directly into the ring buffer. Free up + * the temp buffers when there are no more users. This requires + * special synchronization with current events. + */ +void trace_buffered_event_disable(void) +{ + int cpu; + + WARN_ON_ONCE(!mutex_is_locked(&event_mutex)); + + if (WARN_ON_ONCE(!trace_buffered_event_ref)) + return; + + if (--trace_buffered_event_ref) + return; + + preempt_disable(); + /* For each CPU, set the buffer as used. */ + smp_call_function_many(tracing_buffer_mask, + disable_trace_buffered_event, NULL, 1); + preempt_enable(); + + /* Wait for all current users to finish */ + synchronize_sched(); + + for_each_tracing_cpu(cpu) { + free_page((unsigned long)per_cpu(trace_buffered_event, cpu)); + per_cpu(trace_buffered_event, cpu) = NULL; + } + /* + * Make sure trace_buffered_event is NULL before clearing + * trace_buffered_event_cnt. + */ + smp_wmb(); + + preempt_disable(); + /* Do the work on each cpu */ + smp_call_function_many(tracing_buffer_mask, + enable_trace_buffered_event, NULL, 1); + preempt_enable(); +} + void __buffer_unlock_commit(struct ring_buffer *buffer, struct ring_buffer_event *event) { __this_cpu_write(trace_cmdline_save, true); - ring_buffer_unlock_commit(buffer, event); + + /* If this is the temp buffer, we need to commit fully */ + if (this_cpu_read(trace_buffered_event) == event) { + /* Length is in event->array[0] */ + ring_buffer_write(buffer, event->array[0], &event->array[1]); + /* Release the temp buffer */ + this_cpu_dec(trace_buffered_event_cnt); + } else + ring_buffer_unlock_commit(buffer, event); } static struct ring_buffer *temp_buffer; @@ -1695,8 +1820,23 @@ trace_event_buffer_lock_reserve(struct ring_buffer **current_rb, unsigned long flags, int pc) { struct ring_buffer_event *entry; + int val; *current_rb = trace_file->tr->trace_buffer.buffer; + + if ((trace_file->flags & + (EVENT_FILE_FL_SOFT_DISABLED | EVENT_FILE_FL_FILTERED)) && + (entry = this_cpu_read(trace_buffered_event))) { + /* Try to use the per cpu buffer first */ + val = this_cpu_inc_return(trace_buffered_event_cnt); + if (val == 1) { + trace_event_setup(entry, type, flags, pc); + entry->array[0] = len; + return entry; + } + this_cpu_dec(trace_buffered_event_cnt); + } + entry = trace_buffer_lock_reserve(*current_rb, type, len, flags, pc); /* diff --git a/kernel/trace/trace.h b/kernel/trace/trace.h index 10156a09103f..5167c366d6b7 100644 --- a/kernel/trace/trace.h +++ b/kernel/trace/trace.h @@ -1083,6 +1083,23 @@ static inline void trace_buffer_unlock_commit(struct trace_array *tr, trace_buffer_unlock_commit_regs(tr, buffer, event, flags, pc, NULL); } +DECLARE_PER_CPU(struct ring_buffer_event *, trace_buffered_event); +DECLARE_PER_CPU(int, trace_buffered_event_cnt); +void trace_buffered_event_disable(void); +void trace_buffered_event_enable(void); + +static inline void +__trace_event_discard_commit(struct ring_buffer *buffer, + struct ring_buffer_event *event) +{ + if (this_cpu_read(trace_buffered_event) == event) { + /* Simply release the temp buffer */ + this_cpu_dec(trace_buffered_event_cnt); + return; + } + ring_buffer_discard_commit(buffer, event); +} + /* * Helper function for event_trigger_unlock_commit{_regs}(). * If there are event triggers attached to this event that requires @@ -1111,7 +1128,7 @@ __event_trigger_test_discard(struct trace_event_file *file, if (test_bit(EVENT_FILE_FL_SOFT_DISABLED_BIT, &file->flags) || (unlikely(file->flags & EVENT_FILE_FL_FILTERED) && !filter_match_preds(file->filter, entry))) { - ring_buffer_discard_commit(buffer, event); + __trace_event_discard_commit(buffer, event); return true; } diff --git a/kernel/trace/trace_events.c b/kernel/trace/trace_events.c index da1eeb6190e3..4d006707b947 100644 --- a/kernel/trace/trace_events.c +++ b/kernel/trace/trace_events.c @@ -363,6 +363,7 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file, { struct trace_event_call *call = file->event_call; struct trace_array *tr = file->tr; + unsigned long file_flags = file->flags; int ret = 0; int disable; @@ -445,6 +446,15 @@ static int __ftrace_event_enable_disable(struct trace_event_file *file, break; } + /* Enable or disable use of trace_buffered_event */ + if ((file_flags & EVENT_FILE_FL_SOFT_DISABLED) != + (file->flags & EVENT_FILE_FL_SOFT_DISABLED)) { + if (file->flags & EVENT_FILE_FL_SOFT_DISABLED) + trace_buffered_event_enable(); + else + trace_buffered_event_disable(); + } + return ret; } diff --git a/kernel/trace/trace_events_filter.c b/kernel/trace/trace_events_filter.c index d1d27bf37a19..9daa9b3bc6d9 100644 --- a/kernel/trace/trace_events_filter.c +++ b/kernel/trace/trace_events_filter.c @@ -823,7 +823,12 @@ static void __free_preds(struct event_filter *filter) static void filter_disable(struct trace_event_file *file) { + unsigned long old_flags = file->flags; + file->flags &= ~EVENT_FILE_FL_FILTERED; + + if (old_flags != file->flags) + trace_buffered_event_disable(); } static void __free_filter(struct event_filter *filter) @@ -1698,7 +1703,12 @@ static int replace_preds(struct trace_event_call *call, static inline void event_set_filtered_flag(struct trace_event_file *file) { + unsigned long old_flags = file->flags; + file->flags |= EVENT_FILE_FL_FILTERED; + + if (old_flags != file->flags) + trace_buffered_event_enable(); } static inline void event_set_filter(struct trace_event_file *file,