From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267985AbUHYQAx (ORCPT ); Wed, 25 Aug 2004 12:00:53 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S268042AbUHYQAx (ORCPT ); Wed, 25 Aug 2004 12:00:53 -0400 Received: from mail4.utc.com ([192.249.46.193]:59332 "EHLO mail4.utc.com") by vger.kernel.org with ESMTP id S267985AbUHYQAu (ORCPT ); Wed, 25 Aug 2004 12:00:50 -0400 Message-ID: <412CB78F.9020000@cybsft.com> Date: Wed, 25 Aug 2004 11:00:15 -0500 From: "K.R. Foley" Organization: Cybersoft Solutions, Inc. User-Agent: Mozilla Thunderbird 0.7.3 (X11/20040803) X-Accept-Language: en-us, en MIME-Version: 1.0 To: Lee Revell CC: Ingo Molnar , Scott Wood , manas.saksena@timesys.com, linux-kernel Subject: Re: [patch] voluntary-preempt-2.6.8.1-P9 References: <20040823221816.GA31671@yoda.timesys> <20040824061459.GA29630@elte.hu> <412C04DB.9000508@cybsft.com> <1093404161.5678.12.camel@krustophenia.net> In-Reply-To: <1093404161.5678.12.camel@krustophenia.net> X-Enigmail-Version: 0.85.0.0 X-Enigmail-Supports: pgp-inline, pgp-mime Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Lee Revell wrote: > 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 > > Well I had no sooner sent the last message and another one of these popped up. This one is 123 usec: http://www.cybsft.com/testresults/2.6.8.1-P9/latency_trace12.txt kr