linux-kernel - Re: [PATCH 4/4] sched/fair: Use a recently used CPU as an idle candidate and the basis for SIS

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: <20180130130606.GH2295@hirez.programming.kicks-ass.net>
Date:   Tue, 30 Jan 2018 14:06:06 +0100
From:   Peter Zijlstra <peterz@...radead.org>
To:     Mel Gorman <mgorman@...hsingularity.net>
Cc:     Mike Galbraith <efault@....de>,
        Matt Fleming <matt@...eblueprint.co.uk>,
        LKML <linux-kernel@...r.kernel.org>
Subject: Re: [PATCH 4/4] sched/fair: Use a recently used CPU as an idle
 candidate and the basis for SIS

On Tue, Jan 30, 2018 at 12:53:49PM +0100, Peter Zijlstra wrote:
> On Tue, Jan 30, 2018 at 10:45:55AM +0000, Mel Gorman wrote:
> > The results can be less dramatic on NUMA where automatic balancing interferes
> > with the test. It's also known that network benchmarks running on localhost
> > also benefit quite a bit from this patch (roughly 10% on netperf RR for UDP
> > and TCP depending on the machine). Hackbench also seens small improvements
> > (6-11% depending on machine and thread count). The facebook schbench was also
> > tested but in most cases showed little or no different to wakeup latencies.
> 
> What cpufreq setting were you using for these tests?

I cannot measure any hackbench variation one way or the other with these
patches using 'performance' mode. So I'll assume you've been running
things with HWP or something.