Messages in this thread | | | Date | Sat, 2 Apr 2016 14:32:07 +0200 | From | Frederic Weisbecker <> | Subject | Re: [PATCH 2/4] sched: Correctly handle nohz ticks cpu load accounting |
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On Sat, Apr 02, 2016 at 09:15:20AM +0200, Peter Zijlstra wrote: > On Fri, Apr 01, 2016 at 03:23:05PM +0200, Frederic Weisbecker wrote: > > Ticks can happen in the middle of a nohz frame and > > I'm still miffed with that.. And this changelog doesn't even explain why > and how.
Indeed, it looks like I've cooked sloppy changelogs in this series, I'll do another pass on all of them.
> > > cpu_load_update_active() doesn't handle these correctly. It forgets the > > whole previous tickless load and just records the current tick, ignoring > > potentially long idle periods. > > > > In order to solve this, record the load on nohz frame entry so we know > > what to record in case of nohz interruptions, then use this recorded load > > to account the tickless load on nohz ticks and nohz frame end. > > > > diff --git a/kernel/sched/fair.c b/kernel/sched/fair.c > > index f33764d..394f008 100644 > > --- a/kernel/sched/fair.c > > +++ b/kernel/sched/fair.c > > @@ -4527,9 +4527,9 @@ decay_load_missed(unsigned long load, unsigned long missed_updates, int idx) > > * term. See the @active paramter. > > ^^^^^^^^^^^^^^ > > What active parameter... you need to update that comment.
Yeah, forgot that.
Thanks.
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