Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S271051AbTG1VrY (ORCPT ); Mon, 28 Jul 2003 17:47:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S271064AbTG1VrY (ORCPT ); Mon, 28 Jul 2003 17:47:24 -0400 Received: from fw.osdl.org ([65.172.181.6]:52382 "EHLO mail.osdl.org") by vger.kernel.org with ESMTP id S271051AbTG1VrW (ORCPT ); Mon, 28 Jul 2003 17:47:22 -0400 Date: Mon, 28 Jul 2003 14:35:45 -0700 From: Andrew Morton To: Johoho Cc: wodecki@gmx.de, Valdis.Kletnieks@vt.edu, kernel@kolivas.org, linux-kernel@vger.kernel.org, Nick Piggin Subject: Re: [PATCH] O10int for interactivity Message-Id: <20030728143545.1d989946.akpm@osdl.org> In-Reply-To: <20030728212939.GB6798@gmx.de> References: <200307280112.16043.kernel@kolivas.org> <200307281808.h6SI8C5k004439@turing-police.cc.vt.edu> <20030728114041.2c8ce156.akpm@osdl.org> <20030728212939.GB6798@gmx.de> X-Mailer: Sylpheed version 0.9.4 (GTK+ 1.2.10; i686-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1459 Lines: 36 Wiktor Wodecki wrote: > > On Mon, Jul 28, 2003 at 11:40:41AM -0700, Andrew Morton wrote: > > Valdis.Kletnieks@vt.edu wrote: > > > > > > I am, however, able to get 'xmms' to skip. The reason is that the CPU is being > > > scheduled quite adequately, but I/O is *NOT*. > > > > > > ... > > > I'm guessing that the anticipatory scheduler is the culprit here. Soon as I figure > > > out the incantations to use the deadline scheduler, I'll report back.... > > > > Try decreasing the expiry times in /sys/block/hda/queue/iosched: > > > > read_batch_expire > > read_expire > > write_batch_expire > > write_expire > > I noticed that when bringing a huge application out of swap (mozilla, > openoffice, also tested the gimp with 50 images open) that dividing > everything by 2 in those 4 files I get a decent process fork. Without > this tuning the fork (xterm) waits till the application is back up. Interesting. What we have there is pretty much a straight tradeoff between latency and throughput. It could be that the defaults are not centered in the right spot. It will need some careful characterisation. Maybe we can persuade Nick to generate the mystical Documentation/as-iosched.txt? - 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/