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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2011-05-31 10:49:20 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2011-05-31 14:19:57 +0200 |
| commit | f339b9dc1f03591761d5d930800db24bc0eda1e1 (patch) | |
| tree | 901c78b6e8ccaf9e74515d176084c75389bc2832 | |
| parent | f01114cb59d670e9b4f2c335930dd57db96e9360 (diff) | |
| download | lwn-f339b9dc1f03591761d5d930800db24bc0eda1e1.tar.gz lwn-f339b9dc1f03591761d5d930800db24bc0eda1e1.zip | |
sched: Fix schedstat.nr_wakeups_migrate
While looking over the code I found that with the ttwu rework the
nr_wakeups_migrate test broke since we now switch cpus prior to
calling ttwu_stat(), hence the test is always true.
Cure this by passing the migration state in wake_flags. Also move the
whole test under CONFIG_SMP, its hard to migrate tasks on UP :-)
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Link: http://lkml.kernel.org/n/tip-pwwxl7gdqs5676f1d4cx6pj7@git.kernel.org
Signed-off-by: Ingo Molnar <mingo@elte.hu>
| -rw-r--r-- | include/linux/sched.h | 1 | ||||
| -rw-r--r-- | kernel/sched.c | 11 |
2 files changed, 8 insertions, 4 deletions
diff --git a/include/linux/sched.h b/include/linux/sched.h index 8da84b7bc1b8..483c1ed5bc4d 100644 --- a/include/linux/sched.h +++ b/include/linux/sched.h @@ -1063,6 +1063,7 @@ struct sched_domain; */ #define WF_SYNC 0x01 /* waker goes to sleep after wakup */ #define WF_FORK 0x02 /* child wakeup after fork */ +#define WF_MIGRATED 0x04 /* internal use, task got migrated */ #define ENQUEUE_WAKEUP 1 #define ENQUEUE_HEAD 2 diff --git a/kernel/sched.c b/kernel/sched.c index 49cc70b152cf..2fe98ed474da 100644 --- a/kernel/sched.c +++ b/kernel/sched.c @@ -2447,6 +2447,10 @@ ttwu_stat(struct task_struct *p, int cpu, int wake_flags) } rcu_read_unlock(); } + + if (wake_flags & WF_MIGRATED) + schedstat_inc(p, se.statistics.nr_wakeups_migrate); + #endif /* CONFIG_SMP */ schedstat_inc(rq, ttwu_count); @@ -2455,9 +2459,6 @@ ttwu_stat(struct task_struct *p, int cpu, int wake_flags) if (wake_flags & WF_SYNC) schedstat_inc(p, se.statistics.nr_wakeups_sync); - if (cpu != task_cpu(p)) - schedstat_inc(p, se.statistics.nr_wakeups_migrate); - #endif /* CONFIG_SCHEDSTATS */ } @@ -2675,8 +2676,10 @@ try_to_wake_up(struct task_struct *p, unsigned int state, int wake_flags) p->sched_class->task_waking(p); cpu = select_task_rq(p, SD_BALANCE_WAKE, wake_flags); - if (task_cpu(p) != cpu) + if (task_cpu(p) != cpu) { + wake_flags |= WF_MIGRATED; set_task_cpu(p, cpu); + } #endif /* CONFIG_SMP */ ttwu_queue(p, cpu); |