Messages in this thread | | | Date | Thu, 20 Jul 2023 17:22:26 +0200 | Subject | Re: [RFC PATCH 3/4] sched/fair: delay update_tg_load_avg() for cfs_rq's removed load | From | Dietmar Eggemann <> |
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On 20/07/2023 17:02, Vincent Guittot wrote: > On Thu, 20 Jul 2023 at 16:42, Aaron Lu <aaron.lu@intel.com> wrote: >> >> On Thu, Jul 20, 2023 at 03:10:30PM +0200, Vincent Guittot wrote: >>> On Wed, 19 Jul 2023 at 15:29, Aaron Lu <aaron.lu@intel.com> wrote: >>>> >>>> On Wed, Jul 19, 2023 at 11:47:06AM +0200, Vincent Guittot wrote: >>>>> On Wed, 19 Jul 2023 at 10:01, Aaron Lu <aaron.lu@intel.com> wrote: >>>>>> >>>>>> On Wed, Jul 19, 2023 at 01:18:26PM +0800, Aaron Lu wrote:
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> What was wrong with your proposal to limit the update inside > update_tg_load_avg() ? except maybe s/1000000/NSEC_PER_MSEC/ and > computing delta after testing the time since last update > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > index a80a73909dc2..e48fd0e6982d 100644 > --- a/kernel/sched/fair.c > +++ b/kernel/sched/fair.c > @@ -3665,6 +3665,7 @@ static inline bool cfs_rq_is_decayed(struct > cfs_rq *cfs_rq) > static inline void update_tg_load_avg(struct cfs_rq *cfs_rq) > { > long delta = cfs_rq->avg.load_avg - cfs_rq->tg_load_avg_contrib; > + u64 now = cfs_rq_clock_pelt(cfs_rq);
Could this be `u64 now = sched_clock_cpu()` like in migrate_se_pelt_lag() or newidle_balance() to avoid the time morphing due to PELT's frequency and uArch invariance? > > /* > * No need to update load_avg for root_task_group as it is not used.
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