From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Fri, 21 Feb 2003 00:14:28 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Fri, 21 Feb 2003 00:14:26 -0500 Received: from packet.digeo.com ([12.110.80.53]:35515 "EHLO packet.digeo.com") by vger.kernel.org with ESMTP id ; Fri, 21 Feb 2003 00:14:16 -0500 Date: Thu, 20 Feb 2003 21:25:54 -0800 From: Andrew Morton To: linux-kernel@vger.kernel.org Subject: iosched: time to copy many small files Message-Id: <20030220212554.3e99ec3e.akpm@digeo.com> In-Reply-To: <20030220212304.4712fee9.akpm@digeo.com> References: <20030220212304.4712fee9.akpm@digeo.com> X-Mailer: Sylpheed version 0.8.9 (GTK+ 1.2.10; i586-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 21 Feb 2003 05:24:16.0565 (UTC) FILETIME=[7A40B650:01C2D969] Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org This test simply measures how long it takes to copy a large number of files within the same filesystem. It creates a lot of small, competing read and write I/O's. Changes which were made to the VFS dirty memory handling early in the 2.5 cycle tends to make 2.5 a bit slower at this. Three copies of the 2.4.19 kernel tree were placed on an ext2 filesystem. Measure the time it takes to copy them all to the same filesystem, and to then sync the system. This is just cp -a ./dir-with-three-kernel-trees/ ./new-dir sync The anticipatory scheduler doesn't help here. It could, but we haven't got there yet, and it may need VFS help. 2.4.21-pre4: 70 seconds 2.5.61+hacks: 72 seconds 2.5.61+CFQ: 69 seconds 2.5.61+AS: 66 seconds