Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757991AbYAKDEg (ORCPT ); Thu, 10 Jan 2008 22:04:36 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752381AbYAKDE0 (ORCPT ); Thu, 10 Jan 2008 22:04:26 -0500 Received: from smtp.knology.net ([24.214.63.101]:39788 "EHLO smtp.knology.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751388AbYAKDEZ (ORCPT ); Thu, 10 Jan 2008 22:04:25 -0500 Subject: Re: CONFIG_NO_HZ breaks blktrace timestamps From: David Dillow To: Guillaume Chazarain Cc: linux-kernel@vger.kernel.org, linux-btrace@vger.kernel.org, mingo@redhat.com, tglx@linutronix.de In-Reply-To: <20080110234438.4826f658@inria.fr> References: <1199918912.8388.13.camel@lap75545.ornl.gov> <1199996752.9159.46.camel@lap75545.ornl.gov> <20080110234438.4826f658@inria.fr> Content-Type: text/plain Date: Thu, 10 Jan 2008 22:04:21 -0500 Message-Id: <1200020661.5099.3.camel@obelisk.thedillows.org> Mime-Version: 1.0 X-Mailer: Evolution 2.12.2 (2.12.2-2.fc8) Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1672 Lines: 49 On Thu, 2008-01-10 at 23:44 +0100, Guillaume Chazarain wrote: > David Dillow wrote: > > > At the moment, I'm not sure how to track this farther, or how to fix it > > properly. Any advice would be appreciated. > > Just out of curiosity, could you try the appended cumulative patch and > report .clock_warps, .clock_overflows and .clock_underflows as you did. With those patches, CONFIG_NO_HZ works just fine. Patched kernel, nohz=off: now at 214257.820809 msecs .clock : 214212.727559 .idle_clock : 0.000000 .prev_clock_raw : 244569.402345 .clock_warps : 0 .clock_overflows : 577 .clock_underflows : 213887 .clock_deep_idle_events : 4 .clock_max_delta : 0.999830 Patched kernel, nohz=on: now at 248931.524381 msecs .clock : 248745.808465 .idle_clock : 0.000000 .prev_clock_raw : 270911.098507 .clock_warps : 0 .clock_overflows : 69 .clock_underflows : 784 .clock_deep_idle_events : 4 .clock_max_delta : 100.639397 Running my disk test, blktrace is getting the proper timestamps now with CONFIG_NO_HZ. Thanks! -- Dave Dillow National Center for Computational Science Oak Ridge National Laboratory (865) 241-6602 office -- 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/