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 16:38:52 +0800 |
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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?
Regards, Wanpeng Li
> > se->vruntime += cfs->min_vruntime (switched_to_fair()) > se->vruntime = se->vruntime or bonused value (place_entity()) > > after my patch: > > se->vruntime += cfs->min_vruntime (switched_to_fair()) > se->vruntime = se->vruntime or bonused value (place_entity()) > > --- > > SAME!!! > > in addtion, se->vruntime already had a bonused value if eligible, > when it was detached from cfs_rq. > >>>> after your patch: >>>> >>>> se->vruntime += cfs->min_vruntime (switched_to_fair()) >>>> se->vruntime = se->vruntime (place_entity()) >>>> >>>> >>>> Regards, >>>> Wanpeng Li >>>> >>>> -- >>>> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >>>> the body of a message to majordomo@vger.kernel.org >>>> More majordomo info at http://vger.kernel.org/majordomo-info.html >>>> Please read the FAQ at http://www.tux.org/lkml/ >> -- >> To unsubscribe from this list: send the line "unsubscribe linux-kernel" in >> the body of a message to majordomo@vger.kernel.org >> More majordomo info at http://vger.kernel.org/majordomo-info.html >> Please read the FAQ at http://www.tux.org/lkml/
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