linux-kernel - Re: [RFC][PATCH 0/7] sched: select_idle

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: <20160511141928.i5ewlqwmdna674h4@floor.thefacebook.com>
Date:	Wed, 11 May 2016 10:19:28 -0400
From:	Chris Mason <clm@...com>
To:	Peter Zijlstra <peterz@...radead.org>
CC:	<mingo@...nel.org>, <linux-kernel@...r.kernel.org>,
	<matt@...eblueprint.co.uk>, <mgalbraith@...e.de>,
	<tglx@...utronix.de>, <fweisbec@...il.com>
Subject: Re: [RFC][PATCH 0/7] sched: select_idle_siblings rewrite

On Mon, May 09, 2016 at 12:48:07PM +0200, Peter Zijlstra wrote:
> Hai,
> 
> here be a semi coherent patch series for the recent select_idle_siblings()
> tinkering. Happy benchmarking..

I ran a few more rounds of the production benchmarks, and NO_AVG_CPU is
consistently faster by about 5% than AVG_CPU.  I think what's happening
here is the production runs are ramping up load in a finer grained setup
than schbench, and production is able to see the AVG_CPU calculations
back off the scan too soon (for us anyway).

I'm going to play around with schbench to try and model this better, but
so far this is a clear win over unpatched v4.6.

-chris