Commit-ID: 075e0b00857e166dcc3e39037a1fc5a90acac709
Gitweb: http://git.kernel.org/tip/075e0b00857e166dcc3e39037a1fc5a90acac709
Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
AuthorDate: Sat, 9 Apr 2011 21:17:40 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Sat, 28 May 2011 18:01:09 +0200
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 <oleg@xxxxxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/20110409192141.665385503@xxxxxxxxx
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
---
kernel/events/core.c | 4 ++--
1 files changed, 2 insertions(+), 2 deletions(-)
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);
}
--
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