forked from luck/tmp_suning_uos_patched
x86, bts, hw-branch-tracer: add _noirq variants to the debug store interface
The hw-branch-tracer uses debug store functions from an on_each_cpu() context, which is simply wrong since the functions may sleep. Add _noirq variants for most functions, which may be called with interrupts disabled. Separate per-cpu and per-task tracing and allow per-cpu tracing to be controlled from any cpu. Make the hw-branch-tracer use the new debug store interface, synchronize with hotplug cpu event using get/put_online_cpus(), and remove the unnecessary spinlock. Make the ptrace bts and the ds selftest code use the new interface. Defer the ds selftest. Signed-off-by: Markus Metzger <markus.t.metzger@intel.com> Cc: roland@redhat.com Cc: eranian@googlemail.com Cc: oleg@redhat.com Cc: juan.villacis@intel.com Cc: ak@linux.jf.intel.com LKML-Reference: <20090403144555.658136000@intel.com> Signed-off-by: Ingo Molnar <mingo@elte.hu>
This commit is contained in:
parent
35bb7600c1
commit
de79f54f53
@ -15,8 +15,8 @@
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* - buffer allocation (memory accounting)
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*
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*
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* Copyright (C) 2007-2008 Intel Corporation.
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* Markus Metzger <markus.t.metzger@intel.com>, 2007-2008
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* Copyright (C) 2007-2009 Intel Corporation.
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* Markus Metzger <markus.t.metzger@intel.com>, 2007-2009
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*/
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#ifndef _ASM_X86_DS_H
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@ -83,8 +83,10 @@ enum ds_feature {
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* The interrupt threshold is independent from the overflow callback
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* to allow users to use their own overflow interrupt handling mechanism.
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*
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* task: the task to request recording for;
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* NULL for per-cpu recording on the current cpu
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* The function might sleep.
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*
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* task: the task to request recording for
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* cpu: the cpu to request recording for
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* base: the base pointer for the (non-pageable) buffer;
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* size: the size of the provided buffer in bytes
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* ovfl: pointer to a function to be called on buffer overflow;
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@ -93,19 +95,28 @@ enum ds_feature {
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* -1 if no interrupt threshold is requested.
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* flags: a bit-mask of the above flags
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*/
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extern struct bts_tracer *ds_request_bts(struct task_struct *task,
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void *base, size_t size,
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bts_ovfl_callback_t ovfl,
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size_t th, unsigned int flags);
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extern struct pebs_tracer *ds_request_pebs(struct task_struct *task,
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void *base, size_t size,
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pebs_ovfl_callback_t ovfl,
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size_t th, unsigned int flags);
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extern struct bts_tracer *ds_request_bts_task(struct task_struct *task,
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void *base, size_t size,
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bts_ovfl_callback_t ovfl,
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size_t th, unsigned int flags);
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extern struct bts_tracer *ds_request_bts_cpu(int cpu, void *base, size_t size,
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bts_ovfl_callback_t ovfl,
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size_t th, unsigned int flags);
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extern struct pebs_tracer *ds_request_pebs_task(struct task_struct *task,
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void *base, size_t size,
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pebs_ovfl_callback_t ovfl,
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size_t th, unsigned int flags);
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extern struct pebs_tracer *ds_request_pebs_cpu(int cpu,
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void *base, size_t size,
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pebs_ovfl_callback_t ovfl,
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size_t th, unsigned int flags);
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/*
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* Release BTS or PEBS resources
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* Suspend and resume BTS or PEBS tracing
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*
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* Must be called with irq's enabled.
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*
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* tracer: the tracer handle returned from ds_request_~()
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*/
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extern void ds_release_bts(struct bts_tracer *tracer);
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@ -115,6 +126,28 @@ extern void ds_release_pebs(struct pebs_tracer *tracer);
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extern void ds_suspend_pebs(struct pebs_tracer *tracer);
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extern void ds_resume_pebs(struct pebs_tracer *tracer);
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/*
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* Release BTS or PEBS resources
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* Suspend and resume BTS or PEBS tracing
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*
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* Cpu tracers must call this on the traced cpu.
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* Task tracers must call ds_release_~_noirq() for themselves.
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*
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* May be called with irq's disabled.
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*
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* Returns 0 if successful;
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* -EPERM if the cpu tracer does not trace the current cpu.
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* -EPERM if the task tracer does not trace itself.
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*
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* tracer: the tracer handle returned from ds_request_~()
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*/
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extern int ds_release_bts_noirq(struct bts_tracer *tracer);
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extern int ds_suspend_bts_noirq(struct bts_tracer *tracer);
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extern int ds_resume_bts_noirq(struct bts_tracer *tracer);
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extern int ds_release_pebs_noirq(struct pebs_tracer *tracer);
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extern int ds_suspend_pebs_noirq(struct pebs_tracer *tracer);
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extern int ds_resume_pebs_noirq(struct pebs_tracer *tracer);
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/*
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* The raw DS buffer state as it is used for BTS and PEBS recording.
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@ -245,60 +245,50 @@ struct ds_context {
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struct pebs_tracer *pebs_master;
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/* Use count: */
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unsigned long count;
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unsigned long count;
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/* Pointer to the context pointer field: */
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struct ds_context **this;
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/* The traced task; NULL for current cpu: */
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/* The traced task; NULL for cpu tracing: */
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struct task_struct *task;
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/* The traced cpu; only valid if task is NULL: */
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int cpu;
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};
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static DEFINE_PER_CPU(struct ds_context *, system_context_array);
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#define system_context per_cpu(system_context_array, smp_processor_id())
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static DEFINE_PER_CPU(struct ds_context *, cpu_context);
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static inline struct ds_context *ds_get_context(struct task_struct *task)
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static struct ds_context *ds_get_context(struct task_struct *task, int cpu)
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{
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struct ds_context **p_context =
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(task ? &task->thread.ds_ctx : &system_context);
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(task ? &task->thread.ds_ctx : &per_cpu(cpu_context, cpu));
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struct ds_context *context = NULL;
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struct ds_context *new_context = NULL;
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unsigned long irq;
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/*
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* Chances are small that we already have a context.
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*
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* Contexts for per-cpu tracing are allocated using
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* smp_call_function(). We must not sleep.
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*/
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new_context = kzalloc(sizeof(*new_context), GFP_ATOMIC);
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/* Chances are small that we already have a context. */
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new_context = kzalloc(sizeof(*new_context), GFP_KERNEL);
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if (!new_context)
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return NULL;
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spin_lock_irqsave(&ds_lock, irq);
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spin_lock_irq(&ds_lock);
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context = *p_context;
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if (!context) {
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if (likely(!context)) {
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context = new_context;
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context->this = p_context;
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context->task = task;
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context->cpu = cpu;
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context->count = 0;
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if (task)
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set_tsk_thread_flag(task, TIF_DS_AREA_MSR);
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if (!task || (task == current))
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wrmsrl(MSR_IA32_DS_AREA, (unsigned long)context->ds);
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*p_context = context;
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}
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context->count++;
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spin_unlock_irqrestore(&ds_lock, irq);
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spin_unlock_irq(&ds_lock);
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if (context != new_context)
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kfree(new_context);
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@ -306,7 +296,7 @@ static inline struct ds_context *ds_get_context(struct task_struct *task)
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return context;
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}
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static inline void ds_put_context(struct ds_context *context)
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static void ds_put_context(struct ds_context *context)
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{
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struct task_struct *task;
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unsigned long irq;
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@ -328,8 +318,15 @@ static inline void ds_put_context(struct ds_context *context)
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if (task)
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clear_tsk_thread_flag(task, TIF_DS_AREA_MSR);
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if (!task || (task == current))
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wrmsrl(MSR_IA32_DS_AREA, 0);
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/*
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* We leave the (now dangling) pointer to the DS configuration in
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* the DS_AREA msr. This is as good or as bad as replacing it with
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* NULL - the hardware would crash if we enabled tracing.
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*
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* This saves us some problems with having to write an msr on a
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* different cpu while preventing others from doing the same for the
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* next context for that same cpu.
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*/
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spin_unlock_irqrestore(&ds_lock, irq);
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@ -340,6 +337,31 @@ static inline void ds_put_context(struct ds_context *context)
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kfree(context);
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}
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static void ds_install_ds_area(struct ds_context *context)
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{
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unsigned long ds;
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ds = (unsigned long)context->ds;
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/*
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* There is a race between the bts master and the pebs master.
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*
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* The thread/cpu access is synchronized via get/put_cpu() for
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* task tracing and via wrmsr_on_cpu for cpu tracing.
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*
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* If bts and pebs are collected for the same task or same cpu,
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* the same confiuration is written twice.
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*/
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if (context->task) {
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get_cpu();
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if (context->task == current)
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wrmsrl(MSR_IA32_DS_AREA, ds);
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set_tsk_thread_flag(context->task, TIF_DS_AREA_MSR);
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put_cpu();
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} else
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wrmsr_on_cpu(context->cpu, MSR_IA32_DS_AREA,
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(u32)((u64)ds), (u32)((u64)ds >> 32));
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}
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/*
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* Call the tracer's callback on a buffer overflow.
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@ -622,6 +644,7 @@ static void ds_init_ds_trace(struct ds_trace *trace, enum ds_qualifier qual,
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* The value for 'no threshold' is -1, which will set the
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* threshold outside of the buffer, just like we want it.
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*/
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ith *= ds_cfg.sizeof_rec[qual];
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trace->ith = (void *)(buffer + size - ith);
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trace->flags = flags;
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@ -630,7 +653,7 @@ static void ds_init_ds_trace(struct ds_trace *trace, enum ds_qualifier qual,
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static int ds_request(struct ds_tracer *tracer, struct ds_trace *trace,
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enum ds_qualifier qual, struct task_struct *task,
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void *base, size_t size, size_t th, unsigned int flags)
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int cpu, void *base, size_t size, size_t th)
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{
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struct ds_context *context;
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int error;
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@ -643,7 +666,7 @@ static int ds_request(struct ds_tracer *tracer, struct ds_trace *trace,
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if (!base)
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goto out;
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/* We require some space to do alignment adjustments below. */
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/* We need space for alignment adjustments in ds_init_ds_trace(). */
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error = -EINVAL;
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if (size < (DS_ALIGNMENT + ds_cfg.sizeof_rec[qual]))
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goto out;
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@ -660,25 +683,27 @@ static int ds_request(struct ds_tracer *tracer, struct ds_trace *trace,
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tracer->size = size;
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error = -ENOMEM;
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context = ds_get_context(task);
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context = ds_get_context(task, cpu);
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if (!context)
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goto out;
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tracer->context = context;
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ds_init_ds_trace(trace, qual, base, size, th, flags);
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/*
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* Defer any tracer-specific initialization work for the context until
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* context ownership has been clarified.
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*/
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error = 0;
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out:
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return error;
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}
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struct bts_tracer *ds_request_bts(struct task_struct *task,
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void *base, size_t size,
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bts_ovfl_callback_t ovfl, size_t th,
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unsigned int flags)
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static struct bts_tracer *ds_request_bts(struct task_struct *task, int cpu,
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void *base, size_t size,
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bts_ovfl_callback_t ovfl, size_t th,
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unsigned int flags)
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{
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struct bts_tracer *tracer;
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unsigned long irq;
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int error;
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/* Buffer overflow notification is not yet implemented. */
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@ -690,42 +715,46 @@ struct bts_tracer *ds_request_bts(struct task_struct *task,
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if (error < 0)
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goto out;
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/*
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* Per-cpu tracing is typically requested using smp_call_function().
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* We must not sleep.
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*/
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error = -ENOMEM;
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tracer = kzalloc(sizeof(*tracer), GFP_ATOMIC);
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tracer = kzalloc(sizeof(*tracer), GFP_KERNEL);
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if (!tracer)
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goto out_put_tracer;
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tracer->ovfl = ovfl;
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/* Do some more error checking and acquire a tracing context. */
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error = ds_request(&tracer->ds, &tracer->trace.ds,
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ds_bts, task, base, size, th, flags);
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ds_bts, task, cpu, base, size, th);
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if (error < 0)
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goto out_tracer;
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spin_lock_irqsave(&ds_lock, irq);
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/* Claim the bts part of the tracing context we acquired above. */
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spin_lock_irq(&ds_lock);
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error = -EPERM;
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if (tracer->ds.context->bts_master)
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goto out_unlock;
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tracer->ds.context->bts_master = tracer;
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spin_unlock_irqrestore(&ds_lock, irq);
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spin_unlock_irq(&ds_lock);
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/*
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* Now that we own the bts part of the context, let's complete the
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* initialization for that part.
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*/
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ds_init_ds_trace(&tracer->trace.ds, ds_bts, base, size, th, flags);
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ds_write_config(tracer->ds.context, &tracer->trace.ds, ds_bts);
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ds_install_ds_area(tracer->ds.context);
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tracer->trace.read = bts_read;
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tracer->trace.write = bts_write;
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ds_write_config(tracer->ds.context, &tracer->trace.ds, ds_bts);
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/* Start tracing. */
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ds_resume_bts(tracer);
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return tracer;
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out_unlock:
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spin_unlock_irqrestore(&ds_lock, irq);
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spin_unlock_irq(&ds_lock);
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ds_put_context(tracer->ds.context);
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out_tracer:
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kfree(tracer);
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@ -735,13 +764,27 @@ struct bts_tracer *ds_request_bts(struct task_struct *task,
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return ERR_PTR(error);
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}
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struct pebs_tracer *ds_request_pebs(struct task_struct *task,
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void *base, size_t size,
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pebs_ovfl_callback_t ovfl, size_t th,
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unsigned int flags)
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struct bts_tracer *ds_request_bts_task(struct task_struct *task,
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void *base, size_t size,
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bts_ovfl_callback_t ovfl,
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size_t th, unsigned int flags)
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{
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return ds_request_bts(task, 0, base, size, ovfl, th, flags);
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}
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struct bts_tracer *ds_request_bts_cpu(int cpu, void *base, size_t size,
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bts_ovfl_callback_t ovfl,
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size_t th, unsigned int flags)
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{
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return ds_request_bts(NULL, cpu, base, size, ovfl, th, flags);
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}
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static struct pebs_tracer *ds_request_pebs(struct task_struct *task, int cpu,
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void *base, size_t size,
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pebs_ovfl_callback_t ovfl, size_t th,
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unsigned int flags)
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{
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struct pebs_tracer *tracer;
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unsigned long irq;
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int error;
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/* Buffer overflow notification is not yet implemented. */
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@ -753,37 +796,43 @@ struct pebs_tracer *ds_request_pebs(struct task_struct *task,
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if (error < 0)
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goto out;
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/*
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* Per-cpu tracing is typically requested using smp_call_function().
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* We must not sleep.
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*/
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error = -ENOMEM;
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tracer = kzalloc(sizeof(*tracer), GFP_ATOMIC);
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tracer = kzalloc(sizeof(*tracer), GFP_KERNEL);
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if (!tracer)
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goto out_put_tracer;
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tracer->ovfl = ovfl;
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/* Do some more error checking and acquire a tracing context. */
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error = ds_request(&tracer->ds, &tracer->trace.ds,
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ds_pebs, task, base, size, th, flags);
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ds_pebs, task, cpu, base, size, th);
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if (error < 0)
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goto out_tracer;
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spin_lock_irqsave(&ds_lock, irq);
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/* Claim the pebs part of the tracing context we acquired above. */
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spin_lock_irq(&ds_lock);
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error = -EPERM;
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if (tracer->ds.context->pebs_master)
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goto out_unlock;
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tracer->ds.context->pebs_master = tracer;
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spin_unlock_irqrestore(&ds_lock, irq);
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spin_unlock_irq(&ds_lock);
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/*
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* Now that we own the pebs part of the context, let's complete the
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* initialization for that part.
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*/
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ds_init_ds_trace(&tracer->trace.ds, ds_pebs, base, size, th, flags);
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ds_write_config(tracer->ds.context, &tracer->trace.ds, ds_pebs);
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ds_install_ds_area(tracer->ds.context);
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/* Start tracing. */
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ds_resume_pebs(tracer);
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return tracer;
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out_unlock:
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spin_unlock_irqrestore(&ds_lock, irq);
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spin_unlock_irq(&ds_lock);
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ds_put_context(tracer->ds.context);
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out_tracer:
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kfree(tracer);
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@ -793,17 +842,27 @@ struct pebs_tracer *ds_request_pebs(struct task_struct *task,
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return ERR_PTR(error);
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}
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void ds_release_bts(struct bts_tracer *tracer)
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struct pebs_tracer *ds_request_pebs_task(struct task_struct *task,
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void *base, size_t size,
|
||||
pebs_ovfl_callback_t ovfl,
|
||||
size_t th, unsigned int flags)
|
||||
{
|
||||
return ds_request_pebs(task, 0, base, size, ovfl, th, flags);
|
||||
}
|
||||
|
||||
struct pebs_tracer *ds_request_pebs_cpu(int cpu, void *base, size_t size,
|
||||
pebs_ovfl_callback_t ovfl,
|
||||
size_t th, unsigned int flags)
|
||||
{
|
||||
return ds_request_pebs(NULL, cpu, base, size, ovfl, th, flags);
|
||||
}
|
||||
|
||||
static void ds_free_bts(struct bts_tracer *tracer)
|
||||
{
|
||||
struct task_struct *task;
|
||||
|
||||
if (!tracer)
|
||||
return;
|
||||
|
||||
task = tracer->ds.context->task;
|
||||
|
||||
ds_suspend_bts(tracer);
|
||||
|
||||
WARN_ON_ONCE(tracer->ds.context->bts_master != tracer);
|
||||
tracer->ds.context->bts_master = NULL;
|
||||
|
||||
@ -817,9 +876,69 @@ void ds_release_bts(struct bts_tracer *tracer)
|
||||
kfree(tracer);
|
||||
}
|
||||
|
||||
void ds_release_bts(struct bts_tracer *tracer)
|
||||
{
|
||||
might_sleep();
|
||||
|
||||
if (!tracer)
|
||||
return;
|
||||
|
||||
ds_suspend_bts(tracer);
|
||||
ds_free_bts(tracer);
|
||||
}
|
||||
|
||||
int ds_release_bts_noirq(struct bts_tracer *tracer)
|
||||
{
|
||||
struct task_struct *task;
|
||||
unsigned long irq;
|
||||
int error;
|
||||
|
||||
if (!tracer)
|
||||
return 0;
|
||||
|
||||
task = tracer->ds.context->task;
|
||||
|
||||
local_irq_save(irq);
|
||||
|
||||
error = -EPERM;
|
||||
if (!task &&
|
||||
(tracer->ds.context->cpu != smp_processor_id()))
|
||||
goto out;
|
||||
|
||||
error = -EPERM;
|
||||
if (task && (task != current))
|
||||
goto out;
|
||||
|
||||
ds_suspend_bts_noirq(tracer);
|
||||
ds_free_bts(tracer);
|
||||
|
||||
error = 0;
|
||||
out:
|
||||
local_irq_restore(irq);
|
||||
return error;
|
||||
}
|
||||
|
||||
static void update_task_debugctlmsr(struct task_struct *task,
|
||||
unsigned long debugctlmsr)
|
||||
{
|
||||
task->thread.debugctlmsr = debugctlmsr;
|
||||
|
||||
get_cpu();
|
||||
if (task == current)
|
||||
update_debugctlmsr(debugctlmsr);
|
||||
|
||||
if (task->thread.debugctlmsr)
|
||||
set_tsk_thread_flag(task, TIF_DEBUGCTLMSR);
|
||||
else
|
||||
clear_tsk_thread_flag(task, TIF_DEBUGCTLMSR);
|
||||
put_cpu();
|
||||
}
|
||||
|
||||
void ds_suspend_bts(struct bts_tracer *tracer)
|
||||
{
|
||||
struct task_struct *task;
|
||||
unsigned long debugctlmsr;
|
||||
int cpu;
|
||||
|
||||
if (!tracer)
|
||||
return;
|
||||
@ -827,29 +946,60 @@ void ds_suspend_bts(struct bts_tracer *tracer)
|
||||
tracer->flags = 0;
|
||||
|
||||
task = tracer->ds.context->task;
|
||||
cpu = tracer->ds.context->cpu;
|
||||
|
||||
if (!task || (task == current))
|
||||
update_debugctlmsr(get_debugctlmsr() & ~BTS_CONTROL);
|
||||
WARN_ON(!task && irqs_disabled());
|
||||
|
||||
if (task) {
|
||||
task->thread.debugctlmsr &= ~BTS_CONTROL;
|
||||
debugctlmsr = (task ?
|
||||
task->thread.debugctlmsr :
|
||||
get_debugctlmsr_on_cpu(cpu));
|
||||
debugctlmsr &= ~BTS_CONTROL;
|
||||
|
||||
if (!task->thread.debugctlmsr)
|
||||
clear_tsk_thread_flag(task, TIF_DEBUGCTLMSR);
|
||||
}
|
||||
if (task)
|
||||
update_task_debugctlmsr(task, debugctlmsr);
|
||||
else
|
||||
update_debugctlmsr_on_cpu(cpu, debugctlmsr);
|
||||
}
|
||||
|
||||
void ds_resume_bts(struct bts_tracer *tracer)
|
||||
int ds_suspend_bts_noirq(struct bts_tracer *tracer)
|
||||
{
|
||||
struct task_struct *task;
|
||||
unsigned long control;
|
||||
unsigned long debugctlmsr, irq;
|
||||
int cpu, error = 0;
|
||||
|
||||
if (!tracer)
|
||||
return;
|
||||
return 0;
|
||||
|
||||
tracer->flags = tracer->trace.ds.flags;
|
||||
tracer->flags = 0;
|
||||
|
||||
task = tracer->ds.context->task;
|
||||
cpu = tracer->ds.context->cpu;
|
||||
|
||||
local_irq_save(irq);
|
||||
|
||||
error = -EPERM;
|
||||
if (!task && (cpu != smp_processor_id()))
|
||||
goto out;
|
||||
|
||||
debugctlmsr = (task ?
|
||||
task->thread.debugctlmsr :
|
||||
get_debugctlmsr());
|
||||
debugctlmsr &= ~BTS_CONTROL;
|
||||
|
||||
if (task)
|
||||
update_task_debugctlmsr(task, debugctlmsr);
|
||||
else
|
||||
update_debugctlmsr(debugctlmsr);
|
||||
|
||||
error = 0;
|
||||
out:
|
||||
local_irq_restore(irq);
|
||||
return error;
|
||||
}
|
||||
|
||||
static unsigned long ds_bts_control(struct bts_tracer *tracer)
|
||||
{
|
||||
unsigned long control;
|
||||
|
||||
control = ds_cfg.ctl[dsf_bts];
|
||||
if (!(tracer->trace.ds.flags & BTS_KERNEL))
|
||||
@ -857,25 +1007,77 @@ void ds_resume_bts(struct bts_tracer *tracer)
|
||||
if (!(tracer->trace.ds.flags & BTS_USER))
|
||||
control |= ds_cfg.ctl[dsf_bts_user];
|
||||
|
||||
if (task) {
|
||||
task->thread.debugctlmsr |= control;
|
||||
set_tsk_thread_flag(task, TIF_DEBUGCTLMSR);
|
||||
}
|
||||
|
||||
if (!task || (task == current))
|
||||
update_debugctlmsr(get_debugctlmsr() | control);
|
||||
return control;
|
||||
}
|
||||
|
||||
void ds_release_pebs(struct pebs_tracer *tracer)
|
||||
void ds_resume_bts(struct bts_tracer *tracer)
|
||||
{
|
||||
struct task_struct *task;
|
||||
unsigned long debugctlmsr;
|
||||
int cpu;
|
||||
|
||||
if (!tracer)
|
||||
return;
|
||||
|
||||
task = tracer->ds.context->task;
|
||||
tracer->flags = tracer->trace.ds.flags;
|
||||
|
||||
ds_suspend_pebs(tracer);
|
||||
task = tracer->ds.context->task;
|
||||
cpu = tracer->ds.context->cpu;
|
||||
|
||||
WARN_ON(!task && irqs_disabled());
|
||||
|
||||
debugctlmsr = (task ?
|
||||
task->thread.debugctlmsr :
|
||||
get_debugctlmsr_on_cpu(cpu));
|
||||
debugctlmsr |= ds_bts_control(tracer);
|
||||
|
||||
if (task)
|
||||
update_task_debugctlmsr(task, debugctlmsr);
|
||||
else
|
||||
update_debugctlmsr_on_cpu(cpu, debugctlmsr);
|
||||
}
|
||||
|
||||
int ds_resume_bts_noirq(struct bts_tracer *tracer)
|
||||
{
|
||||
struct task_struct *task;
|
||||
unsigned long debugctlmsr, irq;
|
||||
int cpu, error = 0;
|
||||
|
||||
if (!tracer)
|
||||
return 0;
|
||||
|
||||
tracer->flags = tracer->trace.ds.flags;
|
||||
|
||||
task = tracer->ds.context->task;
|
||||
cpu = tracer->ds.context->cpu;
|
||||
|
||||
local_irq_save(irq);
|
||||
|
||||
error = -EPERM;
|
||||
if (!task && (cpu != smp_processor_id()))
|
||||
goto out;
|
||||
|
||||
debugctlmsr = (task ?
|
||||
task->thread.debugctlmsr :
|
||||
get_debugctlmsr());
|
||||
debugctlmsr |= ds_bts_control(tracer);
|
||||
|
||||
if (task)
|
||||
update_task_debugctlmsr(task, debugctlmsr);
|
||||
else
|
||||
update_debugctlmsr(debugctlmsr);
|
||||
|
||||
error = 0;
|
||||
out:
|
||||
local_irq_restore(irq);
|
||||
return error;
|
||||
}
|
||||
|
||||
static void ds_free_pebs(struct pebs_tracer *tracer)
|
||||
{
|
||||
struct task_struct *task;
|
||||
|
||||
task = tracer->ds.context->task;
|
||||
|
||||
WARN_ON_ONCE(tracer->ds.context->pebs_master != tracer);
|
||||
tracer->ds.context->pebs_master = NULL;
|
||||
@ -886,16 +1088,68 @@ void ds_release_pebs(struct pebs_tracer *tracer)
|
||||
kfree(tracer);
|
||||
}
|
||||
|
||||
void ds_release_pebs(struct pebs_tracer *tracer)
|
||||
{
|
||||
might_sleep();
|
||||
|
||||
if (!tracer)
|
||||
return;
|
||||
|
||||
ds_suspend_pebs(tracer);
|
||||
ds_free_pebs(tracer);
|
||||
}
|
||||
|
||||
int ds_release_pebs_noirq(struct pebs_tracer *tracer)
|
||||
{
|
||||
struct task_struct *task;
|
||||
unsigned long irq;
|
||||
int error;
|
||||
|
||||
if (!tracer)
|
||||
return 0;
|
||||
|
||||
task = tracer->ds.context->task;
|
||||
|
||||
local_irq_save(irq);
|
||||
|
||||
error = -EPERM;
|
||||
if (!task &&
|
||||
(tracer->ds.context->cpu != smp_processor_id()))
|
||||
goto out;
|
||||
|
||||
error = -EPERM;
|
||||
if (task && (task != current))
|
||||
goto out;
|
||||
|
||||
ds_suspend_pebs_noirq(tracer);
|
||||
ds_free_pebs(tracer);
|
||||
|
||||
error = 0;
|
||||
out:
|
||||
local_irq_restore(irq);
|
||||
return error;
|
||||
}
|
||||
|
||||
void ds_suspend_pebs(struct pebs_tracer *tracer)
|
||||
{
|
||||
|
||||
}
|
||||
|
||||
int ds_suspend_pebs_noirq(struct pebs_tracer *tracer)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
void ds_resume_pebs(struct pebs_tracer *tracer)
|
||||
{
|
||||
|
||||
}
|
||||
|
||||
int ds_resume_pebs_noirq(struct pebs_tracer *tracer)
|
||||
{
|
||||
return 0;
|
||||
}
|
||||
|
||||
const struct bts_trace *ds_read_bts(struct bts_tracer *tracer)
|
||||
{
|
||||
if (!tracer)
|
||||
@ -1004,26 +1258,6 @@ ds_configure(const struct ds_configuration *cfg,
|
||||
printk(KERN_INFO "[ds] pebs not available\n");
|
||||
}
|
||||
|
||||
if (ds_cfg.sizeof_rec[ds_bts]) {
|
||||
int error;
|
||||
|
||||
error = ds_selftest_bts();
|
||||
if (error) {
|
||||
WARN(1, "[ds] selftest failed. disabling bts.\n");
|
||||
ds_cfg.sizeof_rec[ds_bts] = 0;
|
||||
}
|
||||
}
|
||||
|
||||
if (ds_cfg.sizeof_rec[ds_pebs]) {
|
||||
int error;
|
||||
|
||||
error = ds_selftest_pebs();
|
||||
if (error) {
|
||||
WARN(1, "[ds] selftest failed. disabling pebs.\n");
|
||||
ds_cfg.sizeof_rec[ds_pebs] = 0;
|
||||
}
|
||||
}
|
||||
|
||||
printk(KERN_INFO "[ds] sizes: address: %u bit, ",
|
||||
8 * ds_cfg.sizeof_ptr_field);
|
||||
printk("bts/pebs record: %u/%u bytes\n",
|
||||
@ -1127,3 +1361,29 @@ void ds_copy_thread(struct task_struct *tsk, struct task_struct *father)
|
||||
void ds_exit_thread(struct task_struct *tsk)
|
||||
{
|
||||
}
|
||||
|
||||
static __init int ds_selftest(void)
|
||||
{
|
||||
if (ds_cfg.sizeof_rec[ds_bts]) {
|
||||
int error;
|
||||
|
||||
error = ds_selftest_bts();
|
||||
if (error) {
|
||||
WARN(1, "[ds] selftest failed. disabling bts.\n");
|
||||
ds_cfg.sizeof_rec[ds_bts] = 0;
|
||||
}
|
||||
}
|
||||
|
||||
if (ds_cfg.sizeof_rec[ds_pebs]) {
|
||||
int error;
|
||||
|
||||
error = ds_selftest_pebs();
|
||||
if (error) {
|
||||
WARN(1, "[ds] selftest failed. disabling pebs.\n");
|
||||
ds_cfg.sizeof_rec[ds_pebs] = 0;
|
||||
}
|
||||
}
|
||||
|
||||
return 0;
|
||||
}
|
||||
device_initcall(ds_selftest);
|
||||
|
@ -10,11 +10,12 @@
|
||||
|
||||
#include <linux/kernel.h>
|
||||
#include <linux/string.h>
|
||||
#include <linux/smp.h>
|
||||
|
||||
#include <asm/ds.h>
|
||||
|
||||
|
||||
#define DS_SELFTEST_BUFFER_SIZE 1021 /* Intentionally chose an odd size. */
|
||||
#define BUFFER_SIZE 1021 /* Intentionally chose an odd size. */
|
||||
|
||||
|
||||
static int ds_selftest_bts_consistency(const struct bts_trace *trace)
|
||||
@ -125,12 +126,12 @@ int ds_selftest_bts(void)
|
||||
struct bts_tracer *tracer;
|
||||
int error = 0;
|
||||
void *top;
|
||||
unsigned char buffer[DS_SELFTEST_BUFFER_SIZE];
|
||||
unsigned char buffer[BUFFER_SIZE];
|
||||
|
||||
printk(KERN_INFO "[ds] bts selftest...");
|
||||
|
||||
tracer = ds_request_bts(NULL, buffer, DS_SELFTEST_BUFFER_SIZE,
|
||||
NULL, (size_t)-1, BTS_KERNEL);
|
||||
tracer = ds_request_bts_cpu(smp_processor_id(), buffer, BUFFER_SIZE,
|
||||
NULL, (size_t)-1, BTS_KERNEL);
|
||||
if (IS_ERR(tracer)) {
|
||||
error = PTR_ERR(tracer);
|
||||
tracer = NULL;
|
||||
|
@ -800,8 +800,9 @@ static int ptrace_bts_config(struct task_struct *child,
|
||||
if (cfg.flags & PTRACE_BTS_O_SCHED)
|
||||
flags |= BTS_TIMESTAMPS;
|
||||
|
||||
context->tracer = ds_request_bts(child, context->buffer, context->size,
|
||||
NULL, (size_t)-1, flags);
|
||||
context->tracer =
|
||||
ds_request_bts_task(child, context->buffer, context->size,
|
||||
NULL, (size_t)-1, flags);
|
||||
if (unlikely(IS_ERR(context->tracer))) {
|
||||
int error = PTR_ERR(context->tracer);
|
||||
|
||||
|
@ -4,7 +4,6 @@
|
||||
* Copyright (C) 2008-2009 Intel Corporation.
|
||||
* Markus Metzger <markus.t.metzger@gmail.com>, 2008-2009
|
||||
*/
|
||||
#include <linux/spinlock.h>
|
||||
#include <linux/kallsyms.h>
|
||||
#include <linux/debugfs.h>
|
||||
#include <linux/ftrace.h>
|
||||
@ -21,168 +20,113 @@
|
||||
|
||||
#define BTS_BUFFER_SIZE (1 << 13)
|
||||
|
||||
/*
|
||||
* The tracer lock protects the below per-cpu tracer array.
|
||||
* It needs to be held to:
|
||||
* - start tracing on all cpus
|
||||
* - stop tracing on all cpus
|
||||
* - start tracing on a single hotplug cpu
|
||||
* - stop tracing on a single hotplug cpu
|
||||
* - read the trace from all cpus
|
||||
* - read the trace from a single cpu
|
||||
*/
|
||||
static DEFINE_SPINLOCK(bts_tracer_lock);
|
||||
static DEFINE_PER_CPU(struct bts_tracer *, tracer);
|
||||
static DEFINE_PER_CPU(unsigned char[BTS_BUFFER_SIZE], buffer);
|
||||
|
||||
#define this_tracer per_cpu(tracer, smp_processor_id())
|
||||
#define this_buffer per_cpu(buffer, smp_processor_id())
|
||||
|
||||
static int trace_hw_branches_enabled __read_mostly;
|
||||
static int trace_hw_branches_suspended __read_mostly;
|
||||
static struct trace_array *hw_branch_trace __read_mostly;
|
||||
|
||||
|
||||
/*
|
||||
* Initialize the tracer for the current cpu.
|
||||
* The argument is ignored.
|
||||
*
|
||||
* pre: bts_tracer_lock must be locked.
|
||||
*/
|
||||
static void bts_trace_init_cpu(void *arg)
|
||||
static void bts_trace_init_cpu(int cpu)
|
||||
{
|
||||
if (this_tracer)
|
||||
ds_release_bts(this_tracer);
|
||||
per_cpu(tracer, cpu) =
|
||||
ds_request_bts_cpu(cpu, per_cpu(buffer, cpu), BTS_BUFFER_SIZE,
|
||||
NULL, (size_t)-1, BTS_KERNEL);
|
||||
|
||||
this_tracer = ds_request_bts(NULL, this_buffer, BTS_BUFFER_SIZE,
|
||||
NULL, (size_t)-1, BTS_KERNEL);
|
||||
if (IS_ERR(this_tracer)) {
|
||||
this_tracer = NULL;
|
||||
return;
|
||||
}
|
||||
if (IS_ERR(per_cpu(tracer, cpu)))
|
||||
per_cpu(tracer, cpu) = NULL;
|
||||
}
|
||||
|
||||
static int bts_trace_init(struct trace_array *tr)
|
||||
{
|
||||
int cpu, avail;
|
||||
|
||||
spin_lock(&bts_tracer_lock);
|
||||
int cpu;
|
||||
|
||||
hw_branch_trace = tr;
|
||||
trace_hw_branches_enabled = 0;
|
||||
|
||||
on_each_cpu(bts_trace_init_cpu, NULL, 1);
|
||||
get_online_cpus();
|
||||
for_each_online_cpu(cpu) {
|
||||
bts_trace_init_cpu(cpu);
|
||||
|
||||
/* Check on how many cpus we could enable tracing */
|
||||
avail = 0;
|
||||
for_each_online_cpu(cpu)
|
||||
if (per_cpu(tracer, cpu))
|
||||
avail++;
|
||||
|
||||
trace_hw_branches_enabled = (avail ? 1 : 0);
|
||||
if (likely(per_cpu(tracer, cpu)))
|
||||
trace_hw_branches_enabled = 1;
|
||||
}
|
||||
trace_hw_branches_suspended = 0;
|
||||
|
||||
spin_unlock(&bts_tracer_lock);
|
||||
|
||||
put_online_cpus();
|
||||
|
||||
/* If we could not enable tracing on a single cpu, we fail. */
|
||||
return avail ? 0 : -EOPNOTSUPP;
|
||||
}
|
||||
|
||||
/*
|
||||
* Release the tracer for the current cpu.
|
||||
* The argument is ignored.
|
||||
*
|
||||
* pre: bts_tracer_lock must be locked.
|
||||
*/
|
||||
static void bts_trace_release_cpu(void *arg)
|
||||
{
|
||||
if (this_tracer) {
|
||||
ds_release_bts(this_tracer);
|
||||
this_tracer = NULL;
|
||||
}
|
||||
return trace_hw_branches_enabled ? 0 : -EOPNOTSUPP;
|
||||
}
|
||||
|
||||
static void bts_trace_reset(struct trace_array *tr)
|
||||
{
|
||||
spin_lock(&bts_tracer_lock);
|
||||
int cpu;
|
||||
|
||||
on_each_cpu(bts_trace_release_cpu, NULL, 1);
|
||||
get_online_cpus();
|
||||
for_each_online_cpu(cpu) {
|
||||
if (likely(per_cpu(tracer, cpu))) {
|
||||
ds_release_bts(per_cpu(tracer, cpu));
|
||||
per_cpu(tracer, cpu) = NULL;
|
||||
}
|
||||
}
|
||||
trace_hw_branches_enabled = 0;
|
||||
trace_hw_branches_suspended = 0;
|
||||
|
||||
spin_unlock(&bts_tracer_lock);
|
||||
}
|
||||
|
||||
/*
|
||||
* Resume tracing on the current cpu.
|
||||
* The argument is ignored.
|
||||
*
|
||||
* pre: bts_tracer_lock must be locked.
|
||||
*/
|
||||
static void bts_trace_resume_cpu(void *arg)
|
||||
{
|
||||
if (this_tracer)
|
||||
ds_resume_bts(this_tracer);
|
||||
put_online_cpus();
|
||||
}
|
||||
|
||||
static void bts_trace_start(struct trace_array *tr)
|
||||
{
|
||||
spin_lock(&bts_tracer_lock);
|
||||
int cpu;
|
||||
|
||||
on_each_cpu(bts_trace_resume_cpu, NULL, 1);
|
||||
get_online_cpus();
|
||||
for_each_online_cpu(cpu)
|
||||
if (likely(per_cpu(tracer, cpu)))
|
||||
ds_resume_bts(per_cpu(tracer, cpu));
|
||||
trace_hw_branches_suspended = 0;
|
||||
|
||||
spin_unlock(&bts_tracer_lock);
|
||||
}
|
||||
|
||||
/*
|
||||
* Suspend tracing on the current cpu.
|
||||
* The argument is ignored.
|
||||
*
|
||||
* pre: bts_tracer_lock must be locked.
|
||||
*/
|
||||
static void bts_trace_suspend_cpu(void *arg)
|
||||
{
|
||||
if (this_tracer)
|
||||
ds_suspend_bts(this_tracer);
|
||||
put_online_cpus();
|
||||
}
|
||||
|
||||
static void bts_trace_stop(struct trace_array *tr)
|
||||
{
|
||||
spin_lock(&bts_tracer_lock);
|
||||
int cpu;
|
||||
|
||||
on_each_cpu(bts_trace_suspend_cpu, NULL, 1);
|
||||
get_online_cpus();
|
||||
for_each_online_cpu(cpu)
|
||||
if (likely(per_cpu(tracer, cpu)))
|
||||
ds_suspend_bts(per_cpu(tracer, cpu));
|
||||
trace_hw_branches_suspended = 1;
|
||||
|
||||
spin_unlock(&bts_tracer_lock);
|
||||
put_online_cpus();
|
||||
}
|
||||
|
||||
static int __cpuinit bts_hotcpu_handler(struct notifier_block *nfb,
|
||||
unsigned long action, void *hcpu)
|
||||
{
|
||||
unsigned int cpu = (unsigned long)hcpu;
|
||||
|
||||
spin_lock(&bts_tracer_lock);
|
||||
|
||||
if (!trace_hw_branches_enabled)
|
||||
goto out;
|
||||
int cpu = (long)hcpu;
|
||||
|
||||
switch (action) {
|
||||
case CPU_ONLINE:
|
||||
case CPU_DOWN_FAILED:
|
||||
smp_call_function_single(cpu, bts_trace_init_cpu, NULL, 1);
|
||||
/* The notification is sent with interrupts enabled. */
|
||||
if (trace_hw_branches_enabled) {
|
||||
bts_trace_init_cpu(cpu);
|
||||
|
||||
if (trace_hw_branches_suspended)
|
||||
smp_call_function_single(cpu, bts_trace_suspend_cpu,
|
||||
NULL, 1);
|
||||
if (trace_hw_branches_suspended &&
|
||||
likely(per_cpu(tracer, cpu)))
|
||||
ds_suspend_bts(per_cpu(tracer, cpu));
|
||||
}
|
||||
break;
|
||||
|
||||
case CPU_DOWN_PREPARE:
|
||||
smp_call_function_single(cpu, bts_trace_release_cpu, NULL, 1);
|
||||
break;
|
||||
/* The notification is sent with interrupts enabled. */
|
||||
if (likely(per_cpu(tracer, cpu))) {
|
||||
ds_release_bts(per_cpu(tracer, cpu));
|
||||
per_cpu(tracer, cpu) = NULL;
|
||||
}
|
||||
}
|
||||
|
||||
out:
|
||||
spin_unlock(&bts_tracer_lock);
|
||||
return NOTIFY_DONE;
|
||||
}
|
||||
|
||||
@ -274,7 +218,7 @@ static void trace_bts_at(const struct bts_trace *trace, void *at)
|
||||
/*
|
||||
* Collect the trace on the current cpu and write it into the ftrace buffer.
|
||||
*
|
||||
* pre: bts_tracer_lock must be locked
|
||||
* pre: tracing must be suspended on the current cpu
|
||||
*/
|
||||
static void trace_bts_cpu(void *arg)
|
||||
{
|
||||
@ -291,10 +235,9 @@ static void trace_bts_cpu(void *arg)
|
||||
if (unlikely(!this_tracer))
|
||||
return;
|
||||
|
||||
ds_suspend_bts(this_tracer);
|
||||
trace = ds_read_bts(this_tracer);
|
||||
if (!trace)
|
||||
goto out;
|
||||
return;
|
||||
|
||||
for (at = trace->ds.top; (void *)at < trace->ds.end;
|
||||
at += trace->ds.size)
|
||||
@ -303,18 +246,27 @@ static void trace_bts_cpu(void *arg)
|
||||
for (at = trace->ds.begin; (void *)at < trace->ds.top;
|
||||
at += trace->ds.size)
|
||||
trace_bts_at(trace, at);
|
||||
|
||||
out:
|
||||
ds_resume_bts(this_tracer);
|
||||
}
|
||||
|
||||
static void trace_bts_prepare(struct trace_iterator *iter)
|
||||
{
|
||||
spin_lock(&bts_tracer_lock);
|
||||
int cpu;
|
||||
|
||||
get_online_cpus();
|
||||
for_each_online_cpu(cpu)
|
||||
if (likely(per_cpu(tracer, cpu)))
|
||||
ds_suspend_bts(per_cpu(tracer, cpu));
|
||||
/*
|
||||
* We need to collect the trace on the respective cpu since ftrace
|
||||
* implicitly adds the record for the current cpu.
|
||||
* Once that is more flexible, we could collect the data from any cpu.
|
||||
*/
|
||||
on_each_cpu(trace_bts_cpu, iter->tr, 1);
|
||||
|
||||
spin_unlock(&bts_tracer_lock);
|
||||
for_each_online_cpu(cpu)
|
||||
if (likely(per_cpu(tracer, cpu)))
|
||||
ds_resume_bts(per_cpu(tracer, cpu));
|
||||
put_online_cpus();
|
||||
}
|
||||
|
||||
static void trace_bts_close(struct trace_iterator *iter)
|
||||
@ -324,12 +276,11 @@ static void trace_bts_close(struct trace_iterator *iter)
|
||||
|
||||
void trace_hw_branch_oops(void)
|
||||
{
|
||||
spin_lock(&bts_tracer_lock);
|
||||
|
||||
if (trace_hw_branches_enabled)
|
||||
if (this_tracer) {
|
||||
ds_suspend_bts_noirq(this_tracer);
|
||||
trace_bts_cpu(hw_branch_trace);
|
||||
|
||||
spin_unlock(&bts_tracer_lock);
|
||||
ds_resume_bts_noirq(this_tracer);
|
||||
}
|
||||
}
|
||||
|
||||
struct tracer bts_tracer __read_mostly =
|
||||
|
Loading…
Reference in New Issue
Block a user