AcoSail/kernel_optimize_test
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function-graph: use int instead of atomic for ftrace_graph_active

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Impact: cleanup

The variable ftrace_graph_active is only modified under the
ftrace_lock mutex, thus an atomic is not necessary for modification.

Reported-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Steven Rostedt <rostedt@goodmis.org>
This commit is contained in:
Steven Rostedt 2009-04-03 15:24:12 -04:00 committed by Ingo Molnar
parent 5452af664f
commit 597af81537
1 changed files with 7 additions and 7 deletions
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14
kernel/trace/ftrace.c
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@ -3092,7 +3092,7 @@ ftrace_enable_sysctl(struct ctl_table *table, int write,
#ifdef CONFIG_FUNCTION_GRAPH_TRACER #ifdef CONFIG_FUNCTION_GRAPH_TRACER
static atomic_t ftrace_graph_active; static int ftrace_graph_active;
static struct notifier_block ftrace_suspend_notifier; static struct notifier_block ftrace_suspend_notifier;
int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace) int ftrace_graph_entry_stub(struct ftrace_graph_ent *trace)
@ -3244,7 +3244,7 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
mutex_lock(&ftrace_lock); mutex_lock(&ftrace_lock);
/* we currently allow only one tracer registered at a time */ /* we currently allow only one tracer registered at a time */
if (atomic_read(&ftrace_graph_active)) { if (ftrace_graph_active) {
ret = -EBUSY; ret = -EBUSY;
goto out; goto out;
} }
@ -3252,10 +3252,10 @@ int register_ftrace_graph(trace_func_graph_ret_t retfunc,
ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call; ftrace_suspend_notifier.notifier_call = ftrace_suspend_notifier_call;
register_pm_notifier(&ftrace_suspend_notifier); register_pm_notifier(&ftrace_suspend_notifier);
atomic_inc(&ftrace_graph_active); ftrace_graph_active++;
ret = start_graph_tracing(); ret = start_graph_tracing();
if (ret) { if (ret) {
atomic_dec(&ftrace_graph_active); ftrace_graph_active--;
goto out; goto out;
} }
@ -3273,10 +3273,10 @@ void unregister_ftrace_graph(void)
{ {
mutex_lock(&ftrace_lock); mutex_lock(&ftrace_lock);
if (!unlikely(atomic_read(&ftrace_graph_active))) if (unlikely(!ftrace_graph_active))
goto out; goto out;
atomic_dec(&ftrace_graph_active); ftrace_graph_active--;
unregister_trace_sched_switch(ftrace_graph_probe_sched_switch); unregister_trace_sched_switch(ftrace_graph_probe_sched_switch);
ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub; ftrace_graph_return = (trace_func_graph_ret_t)ftrace_stub;
ftrace_graph_entry = ftrace_graph_entry_stub; ftrace_graph_entry = ftrace_graph_entry_stub;
@ -3290,7 +3290,7 @@ void unregister_ftrace_graph(void)
/* Allocate a return stack for newly created task */ /* Allocate a return stack for newly created task */
void ftrace_graph_init_task(struct task_struct *t) void ftrace_graph_init_task(struct task_struct *t)
{ {
if (atomic_read(&ftrace_graph_active)) { if (ftrace_graph_active) {
t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH t->ret_stack = kmalloc(FTRACE_RETFUNC_DEPTH
* sizeof(struct ftrace_ret_stack), * sizeof(struct ftrace_ret_stack),
GFP_KERNEL); GFP_KERNEL);