linux-kernel - Re: [External] Re: Subject: [PATCH] sched/fair: prioritize normal task over sched

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

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <CABk29NsBEZ63eQ-avDBHe1LYj+wJNSTkCxPDQ=eTNS9_i9e0NA@mail.gmail.com>
Date:   Mon, 14 Mar 2022 17:30:35 -0700
From:   Josh Don <joshdon@...gle.com>
To:     chenying <chenying.kernel@...edance.com>
Cc:     Peter Zijlstra <peterz@...radead.org>,
        Ingo Molnar <mingo@...hat.com>,
        Juri Lelli <juri.lelli@...hat.com>,
        Vincent Guittot <vincent.guittot@...aro.org>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Mel Gorman <mgorman@...e.de>,
        Daniel Bristot de Oliveira <bristot@...hat.com>,
        Benjamin Segall <bsegall@...gle.com>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        duanxiongchun@...edance.com, zhouchengming@...edance.com,
        songmuchun@...edance.com, zhengqi.arch@...edance.com,
        zhoufeng.zf@...edance.com, ligang.bdlg@...edance.com
Subject: Re: [External] Re: Subject: [PATCH] sched/fair: prioritize normal
 task over sched_idle task with vruntime offset

On Sun, Mar 13, 2022 at 3:07 AM chenying <chenying.kernel@...edance.com> wrote:
>
> If I set the sched_idle_vruntime_offset to a relatively small value
> (e.g. 10 minutes), can this issues be avoided?

That's still long enough to cause lockups.

Is the issue that you have a large number of sched_idle entities, and
the occasional latency sensitive thing that wakes up for a short
duration? Have you considered approaching this from the other
direction (ie. if we have a latency sensitive thing wake onto a cpu
running only sched idle stuff, we could change entity placement to
position the latency sensitive thing further left on the timeline,
akin to !GENTLE_FAIR_SLEEPERS).