From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S268425AbUHYDWn (ORCPT ); Tue, 24 Aug 2004 23:22:43 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268430AbUHYDWn (ORCPT ); Tue, 24 Aug 2004 23:22:43 -0400 Received: from viper.oldcity.dca.net ([216.158.38.4]:62658 "HELO viper.oldcity.dca.net") by vger.kernel.org with SMTP id S268425AbUHYDWl (ORCPT ); Tue, 24 Aug 2004 23:22:41 -0400 Subject: Re: [patch] voluntary-preempt-2.6.8.1-P9 From: Lee Revell To: "K.R. Foley" Cc: Ingo Molnar , Scott Wood , manas.saksena@timesys.com, linux-kernel In-Reply-To: <412C04DB.9000508@cybsft.com> References: <20040823221816.GA31671@yoda.timesys> <20040824061459.GA29630@elte.hu> <412C04DB.9000508@cybsft.com> Content-Type: text/plain Message-Id: <1093404161.5678.12.camel@krustophenia.net> Mime-Version: 1.0 X-Mailer: Ximian Evolution 1.4.6 Date: Tue, 24 Aug 2004 23:22:42 -0400 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 2004-08-24 at 23:17, K.R. Foley wrote: > Ingo Molnar wrote: > > > > http://redhat.com/~mingo/voluntary-preempt/voluntary-preempt-2.6.8.1-P9 > > > latency trace of ~148 usec in scsi_request? I don't know if this is real > or not. Note the 79 usec here: > > 00000001 0.107ms (+0.079ms): sd_init_command (scsi_prep_fn) > > Entire trace is here: > > http://www.cybsft.com/testresults/2.6.8.1-P9/latency_trace7.txt > > > Is this possible? This is not the first time I have seen this. There is > another one here: > > http://www.cybsft.com/testresults/2.6.8.1-P9/latency_trace5.txt > This looks like a real latency. What is /sys/block/sdX/queue/max_sectors_kb set to? Does lowering it help? Lee