On Mon, Jun 27, 2016 at 06:21:11PM +0200, Peter Zijlstra wrote:
> On Fri, Jun 17, 2016 at 12:43:26PM -0500, Josh Poimboeuf wrote:
> > index 017a4f5..0aee5dd 100644
> > --- a/kernel/sched/core.c
> > +++ b/kernel/sched/core.c
> > @@ -1626,10 +1626,15 @@ static inline int __set_cpus_allowed_ptr(struct
> > task_struct *p,
> > static void
> > ttwu_stat(struct task_struct *p, int cpu, int wake_flags)
> > {
> > -#ifdef CONFIG_SCHEDSTATS
> > - struct rq *rq = this_rq();
> > + struct rq *rq;
> > +
> > + if (!schedstat_enabled())
> > + return;
> > +
> > + rq = this_rq();
> >
> > #ifdef CONFIG_SMP
> > +{
> > int this_cpu = smp_processor_id();
> >
> > if (cpu == this_cpu) {
> > @@ -1651,7 +1656,7 @@ ttwu_stat(struct task_struct *p, int cpu, int
> > wake_flags)
> >
> > if (wake_flags & WF_MIGRATED)
> > schedstat_inc(p->se.statistics.nr_wakeups_migrate);
> > -
> > +}
> > #endif /* CONFIG_SMP */
> >
> > schedstat_inc(rq->ttwu_count);
>
> I did:
>
> --- a/kernel/sched/core.c
> +++ b/kernel/sched/core.c
> @@ -1636,10 +1636,7 @@ ttwu_stat(struct task_struct *p, int cpu
> rq = this_rq();
>
> #ifdef CONFIG_SMP
> -{
> - int this_cpu = smp_processor_id();
> -
> - if (cpu == this_cpu) {
> + if (cpu == rq->cpu) {
> schedstat_inc(rq->ttwu_local);
> schedstat_inc(p->se.statistics.nr_wakeups_local);
> } else {
> @@ -1647,7 +1644,7 @@ ttwu_stat(struct task_struct *p, int cpu
>
> schedstat_inc(p->se.statistics.nr_wakeups_remote);
> rcu_read_lock();
> - for_each_domain(this_cpu, sd) {
> + for_each_domain(rq->cpu, sd) {
> if (cpumask_test_cpu(cpu, sched_domain_span(sd))) {
> schedstat_inc(sd->ttwu_wake_remote);
> break;
> @@ -1658,7 +1655,6 @@ ttwu_stat(struct task_struct *p, int cpu
>
> if (wake_flags & WF_MIGRATED)
> schedstat_inc(p->se.statistics.nr_wakeups_migrate);
> -}
> #endif /* CONFIG_SMP */
>
> schedstat_inc(rq->ttwu_count);
Much better, thanks.
--
Josh
