linux-kernel - Re: [PATCH] perf: add 'perf bench syscall'

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:	Mon, 20 Jun 2016 12:16:22 -0700
From:	Andy Lutomirski <luto@...capital.net>
To:	Josh Poimboeuf <jpoimboe@...hat.com>
Cc:	Ingo Molnar <mingo@...nel.org>,
	Arnaldo Carvalho de Melo <acme@...radead.org>,
	Frederic Weisbecker <fweisbec@...il.com>,
	"linux-kernel@...r.kernel.org" <linux-kernel@...r.kernel.org>,
	Thomas Gleixner <tglx@...utronix.de>,
	Rik van Riel <riel@...hat.com>,
	Peter Zijlstra <peterz@...radead.org>, clark@...hat.com,
	Peter Zijlstra <a.p.zijlstra@...llo.nl>
Subject: Re: [PATCH] perf: add 'perf bench syscall'

On Mon, Jun 20, 2016 at 11:00 AM, Josh Poimboeuf <jpoimboe@...hat.com> wrote:

>
> From: Josh Poimboeuf <jpoimboe@...hat.com>
> Subject: [PATCH] perf: add 'perf bench syscall'
>
> Add a basic 'perf bench syscall' benchmark which does a getppid() system
> call in a tight loop.
>

My one suggestion would be to use a different syscall than getppid(),
as getppid() can have unusual performance characteristics on kernels
with pid namespaces enabled.  I'm a fan of prctl(-1, 0, 0, 0, 0).