From 075e0b00857e166dcc3e39037a1fc5a90acac709 Mon Sep 17 00:00:00 2001 From: Peter Zijlstra Date: Sat, 9 Apr 2011 21:17:40 +0200 Subject: perf: Optimize ctx_sched_out() Oleg noted that ctx_sched_out() disables the PMU even though it might not actually do something, avoid needless PMU-disabling. Reported-by: Oleg Nesterov Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/20110409192141.665385503@chello.nl Signed-off-by: Ingo Molnar diff --git a/kernel/events/core.c b/kernel/events/core.c index d863b3c..4d9a1f01 100644 --- a/kernel/events/core.c +++ b/kernel/events/core.c @@ -1760,7 +1760,6 @@ static void ctx_sched_out(struct perf_event_context *ctx, struct perf_event *event; raw_spin_lock(&ctx->lock); - perf_pmu_disable(ctx->pmu); ctx->is_active = 0; if (likely(!ctx->nr_events)) goto out; @@ -1770,6 +1769,7 @@ static void ctx_sched_out(struct perf_event_context *ctx, if (!ctx->nr_active) goto out; + perf_pmu_disable(ctx->pmu); if (event_type & EVENT_PINNED) { list_for_each_entry(event, &ctx->pinned_groups, group_entry) group_sched_out(event, cpuctx, ctx); @@ -1779,8 +1779,8 @@ static void ctx_sched_out(struct perf_event_context *ctx, list_for_each_entry(event, &ctx->flexible_groups, group_entry) group_sched_out(event, cpuctx, ctx); } -out: perf_pmu_enable(ctx->pmu); +out: raw_spin_unlock(&ctx->lock); } -- cgit v0.10.2