linux-kernel - Re: [PATCH] sched/fair: fix find_idlest

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: <CALAqxLXt25qVC+fqdx3rpRMkYwinVKO-Kqw_5B0v=xa01b_AUQ@mail.gmail.com>
Date:   Mon, 16 Dec 2019 17:08:25 -0800
From:   John Stultz <john.stultz@...aro.org>
To:     Vincent Guittot <vincent.guittot@...aro.org>
Cc:     Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Juri Lelli <juri.lelli@...hat.com>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Steven Rostedt <rostedt@...dmis.org>, bsegall@...gle.com,
        "mgorman@...e.de" <mgorman@...e.de>,
        lkml <linux-kernel@...r.kernel.org>,
        Valentin Schneider <valentin.schneider@....com>,
        Qais Yousef <qais.yousef@....com>
Subject: Re: [PATCH] sched/fair: fix find_idlest_group() to handle CPU affinity

On Wed, Dec 4, 2019 at 10:21 AM Vincent Guittot
<vincent.guittot@...aro.org> wrote:
>
> Because of CPU affinity, the local group can be skipped which breaks the
> assumption that statistics are always collected for local group. With
> uninitialized local_sgs, the comparison is meaningless and the behavior
> unpredictable. This can even end up to use local pointer which is to
> NULL in this case.
>
> If the local group has been skipped because of CPU affinity, we return
> the idlest group.
>
> Fixes: 57abff067a08 ("sched/fair: Rework find_idlest_group()")
> Reported-by: John Stultz <john.stultz@...aro.org>
> Signed-off-by: Vincent Guittot <vincent.guittot@...aro.org>
> Tested-by: John Stultz <john.stultz@...aro.org>

Just wanted to follow up on this, as its seemed to have missed -rc2?

thanks
-john