Messages in this thread | | | Subject | Re: [PATCH] sched: fix lose fair sleeper bonus in switch_to_fair() | From | Wanpeng Li <> | Date | Tue, 8 Sep 2015 16:45:46 +0800 |
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On 9/8/15 4:38 PM, Wanpeng Li wrote: > On 9/8/15 4:22 PM, Byungchul Park wrote: >> On Tue, Sep 08, 2015 at 04:04:49PM +0800, Wanpeng Li wrote: >>>>> However, if se->vruntime -= cfs_rq->min_vruntime is positive, the >>>>> behavior is different after your patch. e.g. se->vruntime(the >>>>> relative vruntime in switched_to_fair()) < min_vruntime - >>>>> sysctl_sched_latency/2 >>>>> >>>>> before your patch: >>>>> >>>>> se->vruntime = min_vruntime - sysctl_sched_latency/2 (place_entity()) >>>> my patch is based on ff277d4 commit at tip/sched/core. >>>> >>>> there's no change between before and after. >>>> >>>> check it please. >>>> >>>> and this logic seems to be no problem to me. :( >>> Your logic will lose fair sleeper bonus in the scenario which I >>> pointed out. >> i mean in ff277d4 commit: > > Please include the commit subject when you point out a commit, do you > mean this one? > > commit ff277d4250fe715b6666219b1a3423b863418794 > Author: Andrea Parri <parri.andrea@gmail.com> > Date: Wed Aug 5 15:56:19 2015 +0200 > > sched/deadline: Fix comment in enqueue_task_dl() > > The "dl_boosted" flag is set by comparing *absolute* deadlines > (c.f., rt_mutex_setprio()). > > > What's the relationship w/ this patch?
I think you mean your commit:
commit 7855a35ac07a350e2cd26f09568a6d8e372be358 Author: Byungchul Park <byungchul.park@lge.com> Date: Mon Aug 10 18:02:55 2015 +0900
sched: Ensure a task has a non-normalized vruntime when returning back to CFS
However, that is wrong in the scenario which I mentioned.
Regards, Wanpeng Li
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