linux-kernel - Re: [RFC patch 1/2] sched: dynamically adapt granularity with nr

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: <1284386079.2275.290.camel@laptop>
Date:	Mon, 13 Sep 2010 15:54:39 +0200
From:	Peter Zijlstra <peterz@...radead.org>
To:	Steven Rostedt <rostedt@...dmis.org>
Cc:	Mike Galbraith <efault@....de>,
	Linus Torvalds <torvalds@...ux-foundation.org>,
	Mathieu Desnoyers <mathieu.desnoyers@...icios.com>,
	LKML <linux-kernel@...r.kernel.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Ingo Molnar <mingo@...e.hu>,
	Thomas Gleixner <tglx@...utronix.de>,
	Tony Lindgren <tony@...mide.com>
Subject: Re: [RFC patch 1/2] sched: dynamically adapt granularity with
 nr_running

On Mon, 2010-09-13 at 09:52 -0400, Steven Rostedt wrote:
> On Mon, 2010-09-13 at 10:41 +0200, Peter Zijlstra wrote:
> 
> > Yeah, without it you can starve the already running task on massive
> > forks.
> > 
> > Still, I'm not quite sure why people really care about fork() on time
> > sensitive paths, its a very expensive thing to do, pre-fork() and wake
> > when you need it, is what I would say.
> 
> Fork is used all over the place in Linux. Every shell script uses it to
> execute commands. Bad fork behavior shows up in just doing a build of
> the kernel.

Sure, but there's a difference between bad fork behaviour and the lowest
possible latency. But maybe I'm too paranoid from doing -rt, but the
first thing I'd do is get all resource allocations out from your fast
path.
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/