From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262922AbVFWSdX (ORCPT ); Thu, 23 Jun 2005 14:33:23 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263005AbVFWSdW (ORCPT ); Thu, 23 Jun 2005 14:33:22 -0400 Received: from web30710.mail.mud.yahoo.com ([68.142.200.143]:47232 "HELO web30710.mail.mud.yahoo.com") by vger.kernel.org with SMTP id S262922AbVFWSaz (ORCPT ); Thu, 23 Jun 2005 14:30:55 -0400 DomainKey-Signature: a=rsa-sha1; q=dns; c=nofws; s=s1024; d=yahoo.com; h=Message-ID:Received:Date:From:Reply-To:Subject:To:Cc:In-Reply-To:MIME-Version:Content-Type:Content-Transfer-Encoding; b=2nGvXHPXAYcUVlG8JedWpNSIXGAabL39cHV4hJoTWiu7/Y4njD782QwZFgB1OdAhGwLdvFyercVFABOefVWdeMgtK9kCg2ku1Z8xWDzfB6jEfrN3CZ9Lop8ynG6JAs1k1D+3M6rtEBTNcMUQs7ReP/WVxT86jPH7p2iwqqMVzHU= ; Message-ID: <20050623183051.98655.qmail@web30710.mail.mud.yahoo.com> Date: Thu, 23 Jun 2005 11:30:51 -0700 (PDT) From: Reply-To: spaminos-ker@yahoo.com Subject: Re: cfq misbehaving on 2.6.11-1.14_FC3 To: Jens Axboe Cc: Andrew Morton , linux-kernel@vger.kernel.org In-Reply-To: <20050622204308.GC26925@suse.de> 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 --- Jens Axboe wrote: > Journalled file systems will behave worse for this, because it has to > tend to the journal as well. Can you try mounting that partition as ext2 > and see what numbers that gives you? I did the tests again on a partition that I could mkfs/mount at will. On ext3, I get about 33 seconds average latency. And on ext2, as predicted, I have latencies in average of about 0.4 seconds. I also tried reiserfs, and it gets about 22 seconds latency. As you pointed out, it seems that there is a flow in the way IO queues and journals (that are in some ways queues as well), interact in the presence of flushes. Nicolas