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perf: Fix the software context switch counter

Stephane noticed that because the perf_sw_event() call is inside the
perf_event_task_sched_out() call it won't get called unless we
have a per-task counter.

Reported-by: Stephane Eranian <eranian@google.com>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
master
Peter Zijlstra 11 years ago
committed by Ingo Molnar
parent
commit
ee6dcfa40a
  1. 29
      include/linux/perf_event.h
  2. 2
      kernel/perf_event.c

29
include/linux/perf_event.h

@ -909,20 +909,6 @@ extern int perf_num_counters(void);
extern const char *perf_pmu_name(void);
extern void __perf_event_task_sched_in(struct task_struct *task);
extern void __perf_event_task_sched_out(struct task_struct *task, struct task_struct *next);
extern atomic_t perf_task_events;
static inline void perf_event_task_sched_in(struct task_struct *task)
{
COND_STMT(&perf_task_events, __perf_event_task_sched_in(task));
}
static inline
void perf_event_task_sched_out(struct task_struct *task, struct task_struct *next)
{
COND_STMT(&perf_task_events, __perf_event_task_sched_out(task, next));
}
extern int perf_event_init_task(struct task_struct *child);
extern void perf_event_exit_task(struct task_struct *child);
extern void perf_event_free_task(struct task_struct *task);
@ -1031,6 +1017,21 @@ have_event:
__perf_sw_event(event_id, nr, nmi, regs, addr);
}
extern atomic_t perf_task_events;
static inline void perf_event_task_sched_in(struct task_struct *task)
{
COND_STMT(&perf_task_events, __perf_event_task_sched_in(task));
}
static inline
void perf_event_task_sched_out(struct task_struct *task, struct task_struct *next)
{
perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, NULL, 0);
COND_STMT(&perf_task_events, __perf_event_task_sched_out(task, next));
}
extern void perf_event_mmap(struct vm_area_struct *vma);
extern struct perf_guest_info_callbacks *perf_guest_cbs;
extern int perf_register_guest_info_callbacks(struct perf_guest_info_callbacks *callbacks);

2
kernel/perf_event.c

@ -1287,8 +1287,6 @@ void __perf_event_task_sched_out(struct task_struct *task,
{
int ctxn;
perf_sw_event(PERF_COUNT_SW_CONTEXT_SWITCHES, 1, 1, NULL, 0);
for_each_task_context_nr(ctxn)
perf_event_context_sched_out(task, ctxn, next);
}

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