From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753782AbXJ0GAv (ORCPT ); Sat, 27 Oct 2007 02:00:51 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752070AbXJ0GAl (ORCPT ); Sat, 27 Oct 2007 02:00:41 -0400 Received: from smtp2.linux-foundation.org ([207.189.120.14]:53920 "EHLO smtp2.linux-foundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751728AbXJ0GAk (ORCPT ); Sat, 27 Oct 2007 02:00:40 -0400 Date: Fri, 26 Oct 2007 22:59:51 -0700 From: Andrew Morton To: Arjan van de Ven Cc: Ingo Molnar , spamtrap@knobisoft.de, linux-kernel@vger.kernel.org, a.p.zijlstra@chello.nl, wfg@mail.ustc.edu.cn, torvalds@linux-foundation.org, riel@redhat.com Subject: Re: 2.6.24-rc1: First impressions Message-Id: <20071026225951.db374baf.akpm@linux-foundation.org> In-Reply-To: <20071026224657.11dcf950@laptopd505.fenrus.org> References: <796505.25770.qm@web32612.mail.mud.yahoo.com> <20071026152221.GA26619@elte.hu> <20071026122155.45ce72e7.akpm@linux-foundation.org> <20071026224657.11dcf950@laptopd505.fenrus.org> X-Mailer: Sylpheed 2.4.1 (GTK+ 2.8.17; x86_64-unknown-linux-gnu) 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 On Fri, 26 Oct 2007 22:46:57 -0700 Arjan van de Ven wrote: > > > > dd1 - copy 16 GB from /dev/zero to local FS > > > > dd1-dir - same, but using O_DIRECT for output > > > > dd2/dd2-dir - copy 2x7.6 GB in parallel from /dev/zero to local FS > > > > dd3/dd3-dir - copy 3x5.2 GB in parallel from /dev/zero lo local FS > > > > net1 - copy 5.2 GB from NFS3 share to local FS > > > > mix3 - copy 3x5.2 GB from /dev/zero to local disk and two NFS3 > > > > shares > > > > > > > > I did the numbers for 2.6.19.2, 2.6.22.6 and 2.6.24-rc1. All > > > > units are MB/sec. > > > > > > > > test 2.6.19.2 2.6.22.6 2.6.24.-rc1 > > > > ---------------------------------------------------------------- > > > > dd1 28 50 96 > > > > dd1-dir 88 88 86 > > > > dd2 2x16.5 2x11 2x44.5 > > > > dd2-dir 2x44 2x44 2x43 > > > > dd3 3x9.8 3x8.7 3x30 > > > > dd3-dir 3x29.5 3x29.5 3x28.5 > > > > net1 30-33 50-55 37-52 > > > > mix3 17/32 25/50 96/35 > > > > (disk/combined-network) > > > > > > wow, really nice results! > > > > Those changes seem suspiciously large to me. I wonder if there's less > > physical IO happening during the timed run, and correspondingly more > > afterwards. > > > > another option... this is ext2.. didn't the ext2 reservation stuff get > merged into -rc1? for ext3 that gave a 4x or so speed boost (much > better sequential allocation pattern) > Yes, one would expect that to make a large difference in dd2/dd2-dir and dd3/dd3-dir - but only on SMP. On UP there's not enough concurrency in the fs block allocator for any damage to occur. Reservations won't affect dd1 though, and that went faster too.