Messages in this thread | | | Date | Mon, 29 Apr 2024 14:14:22 +0200 | From | Peter Zijlstra <> | Subject | Re: [RFC][PATCH 08/10] sched/fair: Implement delayed dequeue |
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On Sun, Apr 28, 2024 at 06:32:49PM +0200, Mike Galbraith wrote: > On Sat, 2024-04-27 at 08:42 +0200, Mike Galbraith wrote: > > On Fri, 2024-04-26 at 18:03 +0200, Mike Galbraith wrote: > > > fwiw, tbench liked the previous version better. > > > > The culprit lies somewhere in the new PREEMPT_SHORT patch. > > <squint> > > Ah, moving the curr eligibility check into pick_curr() left an > ineligible curr to be seen/used further down in pick_eevdf(). > > found: > if (!best || (curr && entity_before(curr, best))) > best = curr;
Hmm yes, over aggressive cleanup that. Let me try again.
> Nit: PREEMPT_SHORT depending on RUN_TO_PARITY looks odd.
The thinking was that without RUN_TO_PARITY we'll always do a full pick and it will always pick a (new) shorter deadline task over current.
The PREEMPRT_SHORT thing really is an exception to avoid RUN_TO_PARITY from ruining latency game for short tasks.
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