Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1761416AbXEZPNR (ORCPT ); Sat, 26 May 2007 11:13:17 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1755145AbXEZPNJ (ORCPT ); Sat, 26 May 2007 11:13:09 -0400 Received: from ug-out-1314.google.com ([66.249.92.170]:46260 "EHLO ug-out-1314.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753608AbXEZPNI (ORCPT ); Sat, 26 May 2007 11:13:08 -0400 DomainKey-Signature: a=rsa-sha1; c=nofws; d=gmail.com; s=beta; h=received:message-id:date:from:sender:to:subject:in-reply-to:mime-version:content-type:content-transfer-encoding:content-disposition:references:x-google-sender-auth; b=XgOQE4G1D7BSruiII3sTygoBPtDfXJe/2DVPB4JcIFPeKslBKju4z+U777rDraDicKiUwVUg3Nd7128UtMTZ5f4xKOKai2+CRamVdE4ShISPELosyH8WE+C1PUU/AFcaQw8sigv2lm10RdRUw0T7kLfG8y0MT9aVl8PAEhZ7eAQ= Message-ID: <2c0942db0705260813g6aeedbfepc0afa94ba3550e5b@mail.gmail.com> Date: Sat, 26 May 2007 08:13:06 -0700 From: "Ray Lee" To: "Tommy Vercetti" , LKML Subject: Re: 2.6.21.1 - 97% wait time on IDE operations In-Reply-To: <200705261505.38109@gj-laptop> MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Content-Disposition: inline References: <200705261505.38109@gj-laptop> X-Google-Sender-Auth: cb493464140605a6 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1049 Lines: 21 On 5/26/07, Tommy Vercetti wrote: > I was trying to get answer to my question around, but no one knows. > I do have DMA turned on, etc, yet - on extensive harddrive operations wait You may have DMA turned on, but it may be ineffectual if you don't have the right IDE driver handing your disk. > time is 90+% , which means that machine is waiting, rather than doing > something meanwhile. (I guess). What does hdparm -tT /dev/hda say? If the numbers are reasonable (~400MB/s for cache reads, ~25MB/s for buffered disk reads), then you're just doing a lot of seeking on the drive, and that takes a long time. (Drives can seek about 100 times a second. If every seek reads only 4k of data, that's 400k of data processed per second, or a lot of time spent with the CPU waiting on I/O.) - 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/