Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932244AbWEBWEL (ORCPT ); Tue, 2 May 2006 18:04:11 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932242AbWEBWEL (ORCPT ); Tue, 2 May 2006 18:04:11 -0400 Received: from mx1.redhat.com ([66.187.233.31]:29352 "EHLO mx1.redhat.com") by vger.kernel.org with ESMTP id S932244AbWEBWEJ (ORCPT ); Tue, 2 May 2006 18:04:09 -0400 Date: Tue, 2 May 2006 18:03:37 -0400 From: Dave Jones To: Arjan van de Ven Cc: Wu Fengguang , linux-kernel@vger.kernel.org, Linus Torvalds , Andrew Morton , Jens Axboe , Nick Piggin , Badari Pulavarty Subject: Re: [RFC] kernel facilities for cache prefetching Message-ID: <20060502220337.GB15286@redhat.com> Mail-Followup-To: Dave Jones , Arjan van de Ven , Wu Fengguang , linux-kernel@vger.kernel.org, Linus Torvalds , Andrew Morton , Jens Axboe , Nick Piggin , Badari Pulavarty References: <20060502075049.GA5000@mail.ustc.edu.cn> <1146556724.32045.19.camel@laptopd505.fenrus.org> <20060502080619.GA5406@mail.ustc.edu.cn> <1146558617.32045.23.camel@laptopd505.fenrus.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1146558617.32045.23.camel@laptopd505.fenrus.org> User-Agent: Mutt/1.4.2.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1056 Lines: 28 On Tue, May 02, 2006 at 10:30:17AM +0200, Arjan van de Ven wrote: > one interesting thing that came out of the fedora readahead work is that > most of the bootup isn't actually IO bound. Here's another interesting datapoint. A huge proportion of I/O done during bootup is _completely_ unnecessary. Profiling just a few of the places that seemed to stall yielded some lovely things, like cupsd reading in and parsing descriptions for every printer ever known to man, even if there's no printer connected. Or my favorite.. hald reloading and reparsing the same XML hardware description files.. ~50 times, _each_. Utterly insane. (And these aren't Fedora specific problems btw, every distro shipping those bits will have the same dumb behaviour [modulo versions]) Dave -- http://www.codemonkey.org.uk - 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/