From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from cuda.sgi.com (cuda1.sgi.com [192.48.157.11]) by oss.sgi.com (8.14.3/8.14.3/SuSE Linux 0.8) with ESMTP id o6K85udc008783 for ; Tue, 20 Jul 2010 03:05:57 -0500 Received: from mail.internode.on.net (localhost [127.0.0.1]) by cuda.sgi.com (Spam Firewall) with ESMTP id E1C64BEB18D for ; Tue, 20 Jul 2010 01:15:36 -0700 (PDT) Received: from mail.internode.on.net (bld-mail16.adl2.internode.on.net [150.101.137.101]) by cuda.sgi.com with ESMTP id xh2dWV6LTGMs3qqt for ; Tue, 20 Jul 2010 01:15:36 -0700 (PDT) Date: Tue, 20 Jul 2010 18:08:52 +1000 From: Dave Chinner Subject: Re: [PATCH 3/3] xfs simplify and speed up direct I/O completions Message-ID: <20100720080852.GN32635@dastard> References: <20100718211708.327705876@bombadil.infradead.org> <20100718211820.739557136@bombadil.infradead.org> MIME-Version: 1.0 Content-Disposition: inline In-Reply-To: <20100718211820.739557136@bombadil.infradead.org> List-Id: XFS Filesystem from SGI List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7bit Sender: xfs-bounces@oss.sgi.com Errors-To: xfs-bounces@oss.sgi.com To: Christoph Hellwig Cc: xfs@oss.sgi.com On Sun, Jul 18, 2010 at 05:17:11PM -0400, Christoph Hellwig wrote: > Our current handling of direct I/O completions is rather suboptimal, > because we defer it to a workqueue more often than needed, and we > perform a much to aggressive flush of the workqueue in case unwritten > extent conversions happen. > > This patch changes the direct I/O reads to not even use a completion > handler, as we don't bother to use it at all, and to perform the unwritten > extent conversions in caller context for synchronous direct I/O. > > For a small I/O size direct I/O workload on a consumer grade SSD, such as > the untar of a kernel tree inside qemu this patch gives speedups of > about 5%. Getting us much closer to the speed of a native block device, > or a fully allocated XFS file. > > Signed-off-by: Christoph Hellwig Looks a lot saner - getting rid of the workqueue flushes is a good thing. Reviewed-by: Dave Chinner -- Dave Chinner david@fromorbit.com _______________________________________________ xfs mailing list xfs@oss.sgi.com http://oss.sgi.com/mailman/listinfo/xfs