Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760006AbZATO7T (ORCPT ); Tue, 20 Jan 2009 09:59:19 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755071AbZATO7G (ORCPT ); Tue, 20 Jan 2009 09:59:06 -0500 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:64569 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755203AbZATO7F (ORCPT ); Tue, 20 Jan 2009 09:59:05 -0500 Date: Tue, 20 Jan 2009 09:59:01 -0500 (EST) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: Ingo Molnar cc: Kevin Shanahan , Avi Kivity , "Rafael J. Wysocki" , Linux Kernel Mailing List , Kernel Testers List , Kevin Shanahan , Mike Galbraith , Peter Zijlstra , =?ISO-8859-15?Q?Fr=E9d=E9ric_Weisbecker?= Subject: Re: [Bug #12465] KVM guests stalling on 2.6.28 (bisected) In-Reply-To: <20090120130714.GA11048@elte.hu> Message-ID: References: <1232410363.4768.21.camel@kulgan.wumi.org.au> <20090120113546.GA26571@elte.hu> <1232455343.4895.4.camel@kulgan.wumi.org.au> <20090120125652.GA1457@elte.hu> <20090120130714.GA11048@elte.hu> User-Agent: Alpine 1.10 (DEB 962 2008-03-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 943 Lines: 27 On Tue, 20 Jan 2009, Ingo Molnar wrote: > Another test would be to build the scheduler latency tracer into your > kernel: > > CONFIG_SCHED_TRACER=y > > And enable it via: > > echo wakeup > /debug/tracing/current_tracer > > and you should be seeing the worst-case scheduling latency traces in > /debug/tracing/trace, and the largest observed latency will be in > /debug/tracing/tracing_max_latency [in microseconds]. Note, the wakeup latency only tests realtime threads, since other threads can have other issues for wakeup. I could change the wakeup tracer as wakeup_rt, and make a new "wakeup" that tests all threads, but it may be difficult to get something accurate. -- Steve -- 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/