From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932403AbWEHPbg (ORCPT ); Mon, 8 May 2006 11:31:36 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932404AbWEHPbg (ORCPT ); Mon, 8 May 2006 11:31:36 -0400 Received: from pentafluge.infradead.org ([213.146.154.40]:49635 "EHLO pentafluge.infradead.org") by vger.kernel.org with ESMTP id S932403AbWEHPbg (ORCPT ); Mon, 8 May 2006 11:31:36 -0400 Subject: Re: High load average on disk I/O on 2.6.17-rc3 From: Arjan van de Ven To: Erik Mouw Cc: "Martin J. Bligh" , Andrew Morton , Jason Schoonover , linux-kernel@vger.kernel.org In-Reply-To: <20060508152255.GF1875@harddisk-recovery.com> References: <200605051010.19725.jasons@pioneer-pra.com> <20060507095039.089ad37c.akpm@osdl.org> <445F548A.703@mbligh.org> <1147100149.2888.37.camel@laptopd505.fenrus.org> <20060508152255.GF1875@harddisk-recovery.com> Content-Type: text/plain Date: Mon, 08 May 2006 17:31:29 +0200 Message-Id: <1147102290.2888.41.camel@laptopd505.fenrus.org> Mime-Version: 1.0 X-Mailer: Evolution 2.2.3 (2.2.3-2.fc4) Content-Transfer-Encoding: 7bit X-SRS-Rewrite: SMTP reverse-path rewritten from by pentafluge.infradead.org See http://www.infradead.org/rpr.html Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2006-05-08 at 17:22 +0200, Erik Mouw wrote: > On Mon, May 08, 2006 at 04:55:48PM +0200, Arjan van de Ven wrote: > > On Mon, 2006-05-08 at 07:24 -0700, Martin J. Bligh wrote: > > > > It's pretty harmless though. The "load average" thing just means that the > > > > extra pdflush threads are twiddling thumbs waiting on some disk I/O - > > > > they'll later exit and clean themselves up. They won't be consuming > > > > significant resources. > > > > > > If they're waiting on disk I/O, they shouldn't be runnable, and thus > > > should not be counted as part of the load average, surely? > > > > yes they are, since at least a decade. "load average" != "cpu > > utilisation" by any means. It's "tasks waiting for a hardware resource > > to become available". CPU is one such resource (runnable) but disk is > > another. There are more ... > > ... except that any kernel < 2.6 didn't account tasks waiting for disk > IO. they did. It was "D" state, which counted into load average.