Messages in this thread | | | Subject | Re: [RFC PATCH 3/9] sched: add sched feature to disable idle core search | From | Subhra Mazumdar <> | Date | Thu, 5 Sep 2019 15:02:09 -0700 |
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On 9/5/19 3:17 AM, Patrick Bellasi wrote: > On Fri, Aug 30, 2019 at 18:49:38 +0100, subhra mazumdar wrote... > >> Add a new sched feature SIS_CORE to have an option to disable idle core >> search (select_idle_core). >> >> Signed-off-by: subhra mazumdar <subhra.mazumdar@oracle.com> >> --- >> kernel/sched/features.h | 1 + >> 1 file changed, 1 insertion(+) >> >> diff --git a/kernel/sched/features.h b/kernel/sched/features.h >> index 858589b..de4d506 100644 >> --- a/kernel/sched/features.h >> +++ b/kernel/sched/features.h >> @@ -57,6 +57,7 @@ SCHED_FEAT(TTWU_QUEUE, true) >> */ >> SCHED_FEAT(SIS_AVG_CPU, false) >> SCHED_FEAT(SIS_PROP, true) >> +SCHED_FEAT(SIS_CORE, true) > Why do we need a sched_feature? If you think there are systems in > which the usage of latency-nice does not make sense for in "Select Idle > Sibling", then we should probably better add a new Kconfig option. This is not for latency-nice but to be able to disable a different aspect of the scheduler, i.e searching for idle cores. This can be made part of latency-nice (i.e not do idle core search if latency-nice is below a certain value) but even then having a feature to disable it doesn't hurt. > > If that's the case, you can probably use the init/Kconfig's > "Scheduler features" section, recently added by: > > commit 69842cba9ace ("sched/uclamp: Add CPU's clamp buckets refcounting") > >> /* >> * Issue a WARN when we do multiple update_rq_clock() calls > Best, > Patrick >
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