From mboxrd@z Thu Jan 1 00:00:00 1970 From: Tejun Heo Subject: Re: [PATCH] libata: implement ata_qc_exec_internal() Date: Tue, 29 Nov 2005 12:08:08 +0900 Message-ID: <438BC618.8070300@gmail.com> References: <20051128164201.GA7530@htj.dyndns.org> <5d96567b0511280948t45881bf9x989f27be235b47a1@mail.gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit Return-path: Received: from wproxy.gmail.com ([64.233.184.193]:15656 "EHLO wproxy.gmail.com") by vger.kernel.org with ESMTP id S932342AbVK2DIP (ORCPT ); Mon, 28 Nov 2005 22:08:15 -0500 Received: by wproxy.gmail.com with SMTP id 71so1860094wri for ; Mon, 28 Nov 2005 19:08:14 -0800 (PST) In-Reply-To: <5d96567b0511280948t45881bf9x989f27be235b47a1@mail.gmail.com> Sender: linux-ide-owner@vger.kernel.org List-Id: linux-ide@vger.kernel.org To: "Raz Ben-Jehuda(caro)" Cc: Jeff Garzik , linux-ide@vger.kernel.org Raz Ben-Jehuda(caro) wrote: > does it solve the cpu usage ? > > On 11/28/05, Tejun Heo wrote: > >>Each user libata internal commands initializes a qc, issues it, waits >>for its completion and checks for errors. This patch factors internal >>command execution sequence into ata_qc_exec_internal(). The function >>also removes race condition between irq and timeout handling. >> >>Signed-off-by: Tejun Heo >> Hi, Raz. It propabably has nothing to do with the cpu usage problem on piix you reported. I think you need to post more data to get people on the list interested in your problem. The followings may help. 1. Please report exactly which kernel you're using and more information on the hardware will also help. 2. Don't use raid or any fs on it. Just perform tests on raw /dev/sdx devices. Do something like 'time dd if=/dev/sdx of=/dev/zero bs=1M count=1024' and report how much user/system time it uses. 3. If above shows large system time consumption, build your kernel with oprofile. Start recording non-idle cpu cycles (the default) including the kernel. Repeat test in #2. Dump oprofile result and post that here. Hope it helps. -- tejun