linux-kernel - Re: [PATCH 13/23] sched,ion: Convert to sched_set

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: <CAKfTPtA=d6pnczmU8LFpV=d-9-KArO0qfQuvzod5xYo1pKjK5g@mail.gmail.com>
Date:   Wed, 22 Apr 2020 17:52:55 +0200
From:   Vincent Guittot <vincent.guittot@...aro.org>
To:     Peter Zijlstra <peterz@...radead.org>
Cc:     Ingo Molnar <mingo@...nel.org>,
        linux-kernel <linux-kernel@...r.kernel.org>,
        Thomas Gleixner <tglx@...utronix.de>,
        Steven Rostedt <rostedt@...dmis.org>,
        Qais Yousef <qais.yousef@....com>,
        Juri Lelli <juri.lelli@...hat.com>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
        John Stultz <john.stultz@...aro.org>
Subject: Re: [PATCH 13/23] sched,ion: Convert to sched_set_normal()

On Wed, 22 Apr 2020 at 17:39, Peter Zijlstra <peterz@...radead.org> wrote:
>
> On Wed, Apr 22, 2020 at 05:09:15PM +0200, Vincent Guittot wrote:
> > > It's not unbounded, like a true idle-time scheduler would be, but it can
> > > still be pretty horrible. nice19 has some of that too of course, but
> > > idle has it worse, esp. also because it begs others to preempt it.
> >
> > Yeah... you have to pay the benefit of letting other tasks to preempt
> > faster. But both sched_idle and nice19 have the same weight
>
> #define WEIGHT_IDLEPRIO         3
>
>  /*  15 */        36,        29,        23,        18,        15,
>
> 15 != 3

Good point
Don't know why I thought they had same weight

>
> Also, like said elsewhere, idle is much more eager to let itself be
> preempted.