Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932385AbWEHPW6 (ORCPT ); Mon, 8 May 2006 11:22:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932386AbWEHPW6 (ORCPT ); Mon, 8 May 2006 11:22:58 -0400 Received: from dtp.xs4all.nl ([80.126.206.180]:35428 "HELO abra2.bitwizard.nl") by vger.kernel.org with SMTP id S932385AbWEHPW5 (ORCPT ); Mon, 8 May 2006 11:22:57 -0400 Date: Mon, 8 May 2006 17:22:55 +0200 From: Erik Mouw To: Arjan van de Ven Cc: "Martin J. Bligh" , Andrew Morton , Jason Schoonover , linux-kernel@vger.kernel.org Subject: Re: High load average on disk I/O on 2.6.17-rc3 Message-ID: <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> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1147100149.2888.37.camel@laptopd505.fenrus.org> Organization: Harddisk-recovery.com User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1471 Lines: 32 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. Load average has always been somewhat related to tasks contending for CPU power. It's easy to say "shrug, it changed, live with it", but at least give applications that want to be nice to the system a way to figure out the real cpu load. Erik -- +-- Erik Mouw -- www.harddisk-recovery.com -- +31 70 370 12 90 -- | Lab address: Delftechpark 26, 2628 XH, Delft, The Netherlands - 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/