From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758934AbZJGKxh (ORCPT ); Wed, 7 Oct 2009 06:53:37 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758879AbZJGKxg (ORCPT ); Wed, 7 Oct 2009 06:53:36 -0400 Received: from brick.kernel.dk ([93.163.65.50]:51070 "EHLO kernel.dk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758033AbZJGKxg (ORCPT ); Wed, 7 Oct 2009 06:53:36 -0400 Date: Wed, 7 Oct 2009 12:52:59 +0200 From: Jens Axboe To: Jeff Moyer Cc: zach.brown@oracle.com, linux-aio , Linux Kernel Mailing , Andrew Morton Subject: Re: [patch v4 0/3] aio: implement request batching [more performance numbers] Message-ID: <20091007105259.GD8703@kernel.dk> References: <20091006180628.GB5216@kernel.dk> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Tue, Oct 06 2009, Jeff Moyer wrote: > >> 40K > >> ------------------------------------------------- > >> Kernel NOOP > >> ------ ---- > >> 2.6.30.5 682 > >> 2.6.30.5 (w/o drop_caches) 718 > >> 2.6.30.5+patch_v4 900 > >> 2.6.30.5+patch_v4 (w/o drop caches) 965 > >> > >> > >> 128K > >> ------------------------------------------------- > >> Kernel NOOP > >> ------ ---- > >> 2.6.30.5 242 > >> 2.6.30.5 (w/o drop_caches) 350 > >> 2.6.30.5+patch_v4 292 > >> 2.6.30.5+patch_v4 (w/o drop caches) 420 > > > > Nice numbers! The patch looks good to me from a quick look, if you want > > I can throw it into the testing mix tomorrow and see what kind of > > improvements I see here. With performance increase of that magnitude, we > > should get it in sooner rather than later. > > I'd love it if you could run some benchmarks, thank you! So here's a pretty basic test. It does random reads from a bunch of devices, I tested both 4kb and 64kb block sizes. Queue depth used is 32 for both cases, but note that this test uses a thread per device (so the queue depth is 32 per device). Results are averaged over 3 runs. slat/clat are the submission and completion latencies, they are in microseconds here. 4kb random reads kernel sys IOPS slat clat ---------------------------------------------------- 2.6.32-rc3+patch 25.8% 192500 7.9 2606 2.6.32-rc3 27.4% 191300 8.4 2612 64kb random reads kernel sys IOPS slat clat ---------------------------------------------------- 2.6.32-rc3+patch 2.5% 24590 9.7 9681 2.6.32-rc3 2.5% 24580 9.4 9691 So pretty close, nothing earth shattering here. What the results above do not show is that the 4kb test runs very stable with your patch. Mainline fluctuates somewhat in the bandwidth, most likely due to the varying depth. -- Jens Axboe