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Commit ee6dcfa4 authored by Peter Zijlstra's avatar Peter Zijlstra Committed by Ingo Molnar
Browse files

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: default avatarStephane Eranian <eranian@google.com>
Signed-off-by: default avatarPeter Zijlstra <a.p.zijlstra@chello.nl>
LKML-Reference: <new-submission>
Signed-off-by: default avatarIngo Molnar <mingo@elte.hu>
parent cc2067a5

include/linux/perf_event.h

+15 −14
Original line number Diff line number Diff line
@@ -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 @@ perf_sw_event(u32 event_id, u64 nr, int nmi, struct pt_regs *regs, u64 addr) 
	__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);

kernel/perf_event.c

+0 −2
Original line number Diff line number Diff line
@@ -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);

}