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authorPeter Zijlstra <peterz@infradead.org>2016-01-08 11:05:09 +0100
committerIngo Molnar <mingo@kernel.org>2016-01-21 18:54:22 +0100
commit25432ae96a9889774a05bf5f0f6fd8dbcdec5e72 (patch)
treeb089019db7903744581c3440c25da35a38afab7b
parentaee7dbc45f8aa976913de9b352fa6da816f1f3cd (diff)
downloadop-kernel-dev-25432ae96a9889774a05bf5f0f6fd8dbcdec5e72.zip
op-kernel-dev-25432ae96a9889774a05bf5f0f6fd8dbcdec5e72.tar.gz
perf: Optimize perf_sched_events() usage
It doesn't make sense to take up-to _4_ references on perf_sched_events() per event, avoid doing this. Signed-off-by: Peter Zijlstra (Intel) <peterz@infradead.org> Cc: Arnaldo Carvalho de Melo <acme@redhat.com> Cc: David Ahern <dsahern@gmail.com> Cc: Jiri Olsa <jolsa@redhat.com> Cc: Linus Torvalds <torvalds@linux-foundation.org> Cc: Namhyung Kim <namhyung@kernel.org> Cc: Peter Zijlstra <peterz@infradead.org> Cc: Stephane Eranian <eranian@google.com> Cc: Thomas Gleixner <tglx@linutronix.de> Cc: Vince Weaver <vincent.weaver@maine.edu> Signed-off-by: Ingo Molnar <mingo@kernel.org>
-rw-r--r--kernel/events/core.c22
1 files changed, 16 insertions, 6 deletions
diff --git a/kernel/events/core.c b/kernel/events/core.c
index 079eb9f..935aefd 100644
--- a/kernel/events/core.c
+++ b/kernel/events/core.c
@@ -3491,11 +3491,13 @@ static void unaccount_event_cpu(struct perf_event *event, int cpu)
static void unaccount_event(struct perf_event *event)
{
+ bool dec = false;
+
if (event->parent)
return;
if (event->attach_state & PERF_ATTACH_TASK)
- static_key_slow_dec_deferred(&perf_sched_events);
+ dec = true;
if (event->attr.mmap || event->attr.mmap_data)
atomic_dec(&nr_mmap_events);
if (event->attr.comm)
@@ -3505,12 +3507,15 @@ static void unaccount_event(struct perf_event *event)
if (event->attr.freq)
atomic_dec(&nr_freq_events);
if (event->attr.context_switch) {
- static_key_slow_dec_deferred(&perf_sched_events);
+ dec = true;
atomic_dec(&nr_switch_events);
}
if (is_cgroup_event(event))
- static_key_slow_dec_deferred(&perf_sched_events);
+ dec = true;
if (has_branch_stack(event))
+ dec = true;
+
+ if (dec)
static_key_slow_dec_deferred(&perf_sched_events);
unaccount_event_cpu(event, event->cpu);
@@ -7723,11 +7728,13 @@ static void account_event_cpu(struct perf_event *event, int cpu)
static void account_event(struct perf_event *event)
{
+ bool inc = false;
+
if (event->parent)
return;
if (event->attach_state & PERF_ATTACH_TASK)
- static_key_slow_inc(&perf_sched_events.key);
+ inc = true;
if (event->attr.mmap || event->attr.mmap_data)
atomic_inc(&nr_mmap_events);
if (event->attr.comm)
@@ -7740,11 +7747,14 @@ static void account_event(struct perf_event *event)
}
if (event->attr.context_switch) {
atomic_inc(&nr_switch_events);
- static_key_slow_inc(&perf_sched_events.key);
+ inc = true;
}
if (has_branch_stack(event))
- static_key_slow_inc(&perf_sched_events.key);
+ inc = true;
if (is_cgroup_event(event))
+ inc = true;
+
+ if (inc)
static_key_slow_inc(&perf_sched_events.key);
account_event_cpu(event, event->cpu);
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