From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1161800AbXDYSLq (ORCPT ); Wed, 25 Apr 2007 14:11:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1161864AbXDYSLq (ORCPT ); Wed, 25 Apr 2007 14:11:46 -0400 Received: from brick.kernel.dk ([80.160.20.94]:16834 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1161800AbXDYSLq (ORCPT ); Wed, 25 Apr 2007 14:11:46 -0400 Date: Wed, 25 Apr 2007 20:08:13 +0200 From: Jens Axboe To: Alan.Brunelle@pobox.com Cc: linux-kernel@vger.kernel.org Subject: Re: [PATCH 5/15] cfq-iosched: speed up rbtree handling Message-ID: <20070425180813.GI4730@kernel.dk> References: <11774025432481-git-send-email-jens.axboe@oracle.com> <11774025432403-git-send-email-jens.axboe@oracle.com> <462F7AD9.8020300@hp.com> <20070425171539.GE4730@kernel.dk> <20070425175047.GF4730@kernel.dk> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20070425175047.GF4730@kernel.dk> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Apr 25 2007, Jens Axboe wrote: > On Wed, Apr 25 2007, Jens Axboe wrote: > > On Wed, Apr 25 2007, Alan D. Brunelle wrote: > > > Hi Jens - > > > > > > The attached patch speeds it up even more - I'm finding a >9% reduction > > > in %system with no loss in IO performance. This just sets the cached > > > element when the first is looked for. > > > > Interesting, good thinking. It should not change the IO pattern, as the > > end result should be the same. Thanks Alan, will commit! > > > > I'll give elevator.c the same treatment, should be even more beneficial. > > Stay tuned for a test patch. > > Something like this, totally untested (it compiles). I initially wanted > to fold the cfq addon into the elevator.h provided implementation, but > that requires more extensive changes. Given how little code it is, I > think I'll keep them seperate. Booted, seems to work fine for me. In a null ended IO test, I get about a 1-2% speedup for a single queue of depth 64 using libaio. So it's definitely worth it, will commit. -- Jens Axboe