[tip:sched/locking] sched: Clean up ttwu() stats

From: tip-bot for Peter Zijlstra
Date: Thu Apr 14 2011 - 04:34:32 EST


Commit-ID: d7c01d27ab767a30d672d1fd657aa8336ebdcbca
Gitweb: http://git.kernel.org/tip/d7c01d27ab767a30d672d1fd657aa8336ebdcbca
Author: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
AuthorDate: Tue, 5 Apr 2011 17:23:43 +0200
Committer: Ingo Molnar <mingo@xxxxxxx>
CommitDate: Thu, 14 Apr 2011 08:52:34 +0200

sched: Clean up ttwu() stats

Collect all ttwu() stat code into a single function and ensure its
always called for an actual wakeup (changing p->state to
TASK_RUNNING).

Reviewed-by: Frank Rowand <frank.rowand@xxxxxxxxxxx>
Cc: Mike Galbraith <efault@xxxxxx>
Cc: Nick Piggin <npiggin@xxxxxxxxx>
Cc: Linus Torvalds <torvalds@xxxxxxxxxxxxxxxxxxxx>
Cc: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx>
Signed-off-by: Ingo Molnar <mingo@xxxxxxx>
Signed-off-by: Peter Zijlstra <a.p.zijlstra@xxxxxxxxx>
Link: http://lkml.kernel.org/r/20110405152728.908177058@xxxxxxxxx
---
kernel/sched.c | 75 +++++++++++++++++++++++++++++--------------------------
1 files changed, 40 insertions(+), 35 deletions(-)

diff --git a/kernel/sched.c b/kernel/sched.c
index 3919aa4..4481638 100644
--- a/kernel/sched.c
+++ b/kernel/sched.c
@@ -2406,20 +2406,43 @@ static void update_avg(u64 *avg, u64 sample)
}
#endif

-static inline void ttwu_activate(struct task_struct *p, struct rq *rq,
- bool is_sync, bool is_migrate, bool is_local,
- unsigned long en_flags)
+static void
+ttwu_stat(struct rq *rq, struct task_struct *p, int cpu, int wake_flags)
{
+#ifdef CONFIG_SCHEDSTATS
+#ifdef CONFIG_SMP
+ int this_cpu = smp_processor_id();
+
+ if (cpu == this_cpu) {
+ schedstat_inc(rq, ttwu_local);
+ schedstat_inc(p, se.statistics.nr_wakeups_local);
+ } else {
+ struct sched_domain *sd;
+
+ schedstat_inc(p, se.statistics.nr_wakeups_remote);
+ for_each_domain(this_cpu, sd) {
+ if (cpumask_test_cpu(cpu, sched_domain_span(sd))) {
+ schedstat_inc(sd, ttwu_wake_remote);
+ break;
+ }
+ }
+ }
+#endif /* CONFIG_SMP */
+
+ schedstat_inc(rq, ttwu_count);
schedstat_inc(p, se.statistics.nr_wakeups);
- if (is_sync)
+
+ if (wake_flags & WF_SYNC)
schedstat_inc(p, se.statistics.nr_wakeups_sync);
- if (is_migrate)
+
+ if (cpu != task_cpu(p))
schedstat_inc(p, se.statistics.nr_wakeups_migrate);
- if (is_local)
- schedstat_inc(p, se.statistics.nr_wakeups_local);
- else
- schedstat_inc(p, se.statistics.nr_wakeups_remote);

+#endif /* CONFIG_SCHEDSTATS */
+}
+
+static void ttwu_activate(struct rq *rq, struct task_struct *p, int en_flags)
+{
activate_task(rq, p, en_flags);

/* if a worker is waking up, notify workqueue */
@@ -2481,12 +2504,12 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
if (!(p->state & state))
goto out;

+ cpu = task_cpu(p);
+
if (p->se.on_rq)
goto out_running;

- cpu = task_cpu(p);
orig_cpu = cpu;
-
#ifdef CONFIG_SMP
if (unlikely(task_running(rq, p)))
goto out_activate;
@@ -2527,27 +2550,12 @@ static int try_to_wake_up(struct task_struct *p, unsigned int state,
WARN_ON(task_cpu(p) != cpu);
WARN_ON(p->state != TASK_WAKING);

-#ifdef CONFIG_SCHEDSTATS
- schedstat_inc(rq, ttwu_count);
- if (cpu == this_cpu)
- schedstat_inc(rq, ttwu_local);
- else {
- struct sched_domain *sd;
- for_each_domain(this_cpu, sd) {
- if (cpumask_test_cpu(cpu, sched_domain_span(sd))) {
- schedstat_inc(sd, ttwu_wake_remote);
- break;
- }
- }
- }
-#endif /* CONFIG_SCHEDSTATS */
-
out_activate:
#endif /* CONFIG_SMP */
- ttwu_activate(p, rq, wake_flags & WF_SYNC, orig_cpu != cpu,
- cpu == this_cpu, en_flags);
+ ttwu_activate(rq, p, en_flags);
out_running:
ttwu_post_activation(p, rq, wake_flags);
+ ttwu_stat(rq, p, cpu, wake_flags);
success = 1;
out:
task_rq_unlock(rq, &flags);
@@ -2575,14 +2583,11 @@ static void try_to_wake_up_local(struct task_struct *p)
if (!(p->state & TASK_NORMAL))
return;

- if (!p->se.on_rq) {
- if (likely(!task_running(rq, p))) {
- schedstat_inc(rq, ttwu_count);
- schedstat_inc(rq, ttwu_local);
- }
- ttwu_activate(p, rq, false, false, true, ENQUEUE_WAKEUP);
- }
+ if (!p->se.on_rq)
+ ttwu_activate(rq, p, ENQUEUE_WAKEUP);
+
ttwu_post_activation(p, rq, 0);
+ ttwu_stat(rq, p, smp_processor_id(), 0);
}

/**
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