[PATCH 05/12] perf: move perf_event_task_sched_in() next to fire_sched_notifiers_in()
in [Kernel]
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From: Tejun Heo on 4 May 2010 08:50 Move perf_event_task_sched_in() after finish_lock_switch() right before fire_sched_notifiers_in(). This costs an extra pair of irq enable/disable when switching in a perf task context but allows unifying event functions in a more flexible position (irq enabled, rq lock released). Signed-off-by: Tejun Heo <tj(a)kernel.org> Cc: Peter Zijlstra <a.p.zijlstra(a)chello.nl> Cc: Paul Mackerras <paulus(a)samba.org> Cc: Ingo Molnar <mingo(a)elte.hu> Cc: Arnaldo Carvalho de Melo <acme(a)redhat.com> --- kernel/perf_event.c | 9 +++++++-- kernel/sched.c | 8 +------- 2 files changed, 8 insertions(+), 9 deletions(-) diff --git a/kernel/perf_event.c b/kernel/perf_event.c index 73e2c1c..295699f 100644 --- a/kernel/perf_event.c +++ b/kernel/perf_event.c @@ -1369,14 +1369,17 @@ static void task_ctx_sched_in(struct task_struct *task, */ void perf_event_task_sched_in(struct task_struct *task) { - struct perf_cpu_context *cpuctx = &__get_cpu_var(perf_cpu_context); struct perf_event_context *ctx = task->perf_event_ctxp; + struct perf_cpu_context *cpuctx; if (likely(!ctx)) return; + local_irq_disable(); + + cpuctx = &__get_cpu_var(perf_cpu_context); if (cpuctx->task_ctx == ctx) - return; + goto out_enable; /* * We want to keep the following priority order: @@ -1390,6 +1393,8 @@ void perf_event_task_sched_in(struct task_struct *task) ctx_sched_in(ctx, cpuctx, EVENT_FLEXIBLE); cpuctx->task_ctx = ctx; +out_enable: + local_irq_enable(); } #define MAX_INTERRUPTS (~0ULL) diff --git a/kernel/sched.c b/kernel/sched.c index 4c5e4c9..df6e0af 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2794,15 +2794,9 @@ static void finish_task_switch(struct rq *rq, struct task_struct *prev) */ prev_state = prev->state; finish_arch_switch(prev); -#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW - local_irq_disable(); -#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ - perf_event_task_sched_in(current); -#ifdef __ARCH_WANT_INTERRUPTS_ON_CTXSW - local_irq_enable(); -#endif /* __ARCH_WANT_INTERRUPTS_ON_CTXSW */ finish_lock_switch(rq, prev); + perf_event_task_sched_in(current); fire_sched_notifiers_in(current); if (mm) mmdrop(mm); -- 1.6.4.2 -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo(a)vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/ |