From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263782AbTKDHvF (ORCPT ); Tue, 4 Nov 2003 02:51:05 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263783AbTKDHvF (ORCPT ); Tue, 4 Nov 2003 02:51:05 -0500 Received: from ns.suse.de ([195.135.220.2]:59088 "EHLO Cantor.suse.de") by vger.kernel.org with ESMTP id S263782AbTKDHvC (ORCPT ); Tue, 4 Nov 2003 02:51:02 -0500 Date: Tue, 4 Nov 2003 08:49:28 +0100 From: Jens Axboe To: ahuisman Cc: linux-kernel@vger.kernel.org Subject: Re: CONFIG_IOSCHED_CFQ Message-ID: <20031104074927.GA1477@suse.de> References: Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sun, Oct 26 2003, ahuisman wrote: > wuuk:/boot# diff config-2.6.0-test8-mm1 config-2.6.0-test9 > 33d32 > < CONFIG_IOSCHED_CFQ=y > 87,91d85 > < # CONFIG_X86_4G is not set > < # CONFIG_X86_SWITCH_PAGETABLES is not set > < # CONFIG_X86_4G_VM_LAYOUT is not set > < # CONFIG_X86_UACCESS_INDIRECT is not set > < # CONFIG_X86_HIGH_ENTRY is not set > 111d104 > < CONFIG_BOOT_IOREMAP=y > 257d249 > < # CONFIG_BLK_DEV_SGIIOC4 is not set > 302a295 > > # CONFIG_SCSI_SATA is not set > 483d475 > < # CONFIG_NET_POLL_CONTROLLER is not set > > Conclusion: > > CONFIG_IOSCHED_CFQ is removed from 2.6.0-test9 > > Questions: > > Am i right with my conclusion ? > Is this the reason for the loss of performance ? No you are not correct, must be caused by something else. Just building CFQ into the kernel doesn't enable it, you need to boot with elevator=cfq for that to happen. So whether CONFIG_IOSCHED_CFQ is set or not cannot make a difference by itself. The performance difference must be caused by some other change between test8-mm1 and -test9. -- Jens Axboe