| lists.openwall.net | lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC | |
|
Open Source and information security mailing list archives
| ||
|
Date: Tue, 8 Sep 2015 17:22:40 +0900 From: Byungchul Park <byungchul.park@....com> To: Wanpeng Li <wanpeng.li@...mail.com> Cc: Peter Zijlstra <peterz@...radead.org>, Ingo Molnar <mingo@...nel.org>, linux-kernel@...r.kernel.org, yuyang.du@...el.com Subject: Re: [PATCH] sched: fix lose fair sleeper bonus in switch_to_fair() 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: 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@...r.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@...r.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@...r.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/
Powered by blists - more mailing lists