linux-kernel - Re: [PATCH v6 0/2] sched: Optionally skip uclamp logic in fast path

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]

Date:   Tue, 7 Jul 2020 14:29:39 +0200
From:   Vincent Guittot <vincent.guittot@...aro.org>
To:     Qais Yousef <qais.yousef@....com>
Cc:     Ingo Molnar <mingo@...hat.com>,
        Peter Zijlstra <peterz@...radead.org>,
        Valentin Schneider <valentin.schneider@....com>,
        Juri Lelli <juri.lelli@...hat.com>,
        Dietmar Eggemann <dietmar.eggemann@....com>,
        Steven Rostedt <rostedt@...dmis.org>,
        Ben Segall <bsegall@...gle.com>, Mel Gorman <mgorman@...e.de>,
        Patrick Bellasi <patrick.bellasi@...bug.net>,
        Chris Redpath <chris.redpath@....com>,
        Lukasz Luba <lukasz.luba@....com>,
        linux-kernel <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH v6 0/2] sched: Optionally skip uclamp logic in fast path

On Mon, 6 Jul 2020 at 12:41, Qais Yousef <qais.yousef@....com> wrote:
>
> On 07/03/20 14:09, Vincent Guittot wrote:
> > I have run the perf bench sched pipe that have have already run
> > previously with this v6 and the results are similar to my previous
> > tests:
> > The impact is -1.61% similarly to v2 which is better compared the
> > original -3.66% without your patch
>
> Thanks Vincent.
>
> Can you afford doing a capture of `perf record` and share the resulting
> perf.dat with vmlinux (with debug symbols)?

Will try to make it by end of the week

>
> Having a before/after capture would be even better.
>
> Not sure if we can do  much about this -1.61% in your case, but it'd be good to
> understand why if possible. perf bench sched pipe is very sensitive to tiniest
> of changes which could be due to binary-to-binary differences.
>
> Thanks
>
> --
> Qais Yousef