Return-path: Received: from mail.gmx.net ([213.165.64.20]:38364 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S932308AbZJIDFX (ORCPT ); Thu, 8 Oct 2009 23:05:23 -0400 Subject: Re: [.32-rc3] scheduler: iwlagn consistently high in "waiting for CPU" From: Mike Galbraith To: Frans Pop Cc: Arjan van de Ven , Linux Kernel Mailing List , Ingo Molnar , Peter Zijlstra , linux-wireless@vger.kernel.org In-Reply-To: <200910082259.35204.elendil@planet.nl> References: <200910051500.55875.elendil@planet.nl> <200910081655.37485.elendil@planet.nl> <1255026217.6643.12.camel@marge.simson.net> <200910082259.35204.elendil@planet.nl> Content-Type: text/plain Date: Fri, 09 Oct 2009 05:04:33 +0200 Message-Id: <1255057473.6600.11.camel@marge.simson.net> Mime-Version: 1.0 Sender: linux-wireless-owner@vger.kernel.org List-ID: On Thu, 2009-10-08 at 22:59 +0200, Frans Pop wrote: > On Thursday 08 October 2009, Mike Galbraith wrote: > > I still see very high latencies coming out of idle (last noted was > > > 300ms, NO_HZ) with this patch, > > > > Like this: > > > > Cause Maximum Percentage > > Scheduler: waiting for cpu 604.2 msec 49.0 % > > I'm not seeing anything even remotely like that. > > I've tried quieting the system down as much as possible, but that made > no difference. I do have NO_HZ set; will send my full config privately. > > If you'd still like me to try your patch I will, but I'm not sure if > that has much value. No, if you watch for a bit with box mostly idle, and don't see > 100ms hits occasionally, testing patchlet is likely a waste of time. To get one like the above, I have to hold my tongue just right ;-) they're not common. -Mike