Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1764710AbXKPNxe (ORCPT ); Fri, 16 Nov 2007 08:53:34 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1757550AbXKPNxZ (ORCPT ); Fri, 16 Nov 2007 08:53:25 -0500 Received: from mail.gmx.net ([213.165.64.20]:52706 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1756297AbXKPNxZ (ORCPT ); Fri, 16 Nov 2007 08:53:25 -0500 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX1+4nvkmDtG4Tlt2AEqByyEY34OmfCj0Mf3MbBxj1I EiOHhqc1Y2crdS Subject: Re: [BUG] Strange 1-second pauses during Resume-from-RAM From: Mike Galbraith To: Ingo Molnar Cc: Mark Lord , Pavel Machek , Mark Lord , Thomas Gleixner , len.brown@intel.com, Andrew Morton , linux-kernel@vger.kernel.org, linux-pm@lists.linux-foundation.org, rjw@sisk.pl, Len Brown In-Reply-To: <20071116112317.GA12724@elte.hu> References: <4739E347.30406@rtr.ca> <473C7495.40805@rtr.ca> <20071115181418.GA6603@ucw.cz> <473C825E.3030307@rtr.ca> <20071115193424.GA31691@elte.hu> <20071115193612.GA751@elte.hu> <473CC6D4.2010909@rtr.ca> <20071116055531.GA16273@elte.hu> <20071116071522.GA1453@elte.hu> <20071116082146.GA14685@elte.hu> <20071116112317.GA12724@elte.hu> Content-Type: text/plain Date: Fri, 16 Nov 2007 06:53:13 -0500 Message-Id: <1195213993.4037.21.camel@Knoppix> Mime-Version: 1.0 X-Mailer: Evolution 2.6.3 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1349 Lines: 34 On Fri, 2007-11-16 at 12:23 +0100, Ingo Molnar wrote: > * Ingo Molnar wrote: > > > once that tracer bug was fixed, the best method to generate a trace > > was to do this: > > > > echo 1 > /proc/sys/kernel/stackframe_tracing > > echo 1 > /proc/sys/kernel/syscall_tracing > > ./trace-cmd bash -c "echo mem > /sys/power/state" > trace.txt > > so here's an UP suspend+resume trace i did: > > http://redhat.com/~mingo/latency-tracing-patches/misc/trace-suspend-long.txt.bz2 > > tons of detail - which might be interesting to other folks as well. Fact > is, our suspend-to-RAM+resume cycle is very, very slow, even on fast > hardware - and this trace shows all the reasons why. > > This was a fully cached system - i.e. i've done a suspend+resume before > to warm up the caches. (not that suspend+resume does much IO normally.) > > The trace shows that a suspend+resume cycle is 7.95 seconds long > (without counting the time the box spent suspended) - ouch! This was a > T60 with Core2Duo 1.83GHz. Ouch? That's an order of magnitude faster than my 3GHz P4 :) -Mike - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/