From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S261424AbVFOMVV (ORCPT ); Wed, 15 Jun 2005 08:21:21 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S261430AbVFOMVU (ORCPT ); Wed, 15 Jun 2005 08:21:20 -0400 Received: from e35.co.us.ibm.com ([32.97.110.133]:59895 "EHLO e35.co.us.ibm.com") by vger.kernel.org with ESMTP id S261424AbVFOMVM (ORCPT ); Wed, 15 Jun 2005 08:21:12 -0400 Date: Wed, 15 Jun 2005 17:48:42 +0530 From: Dipankar Sarma To: Andrew Morton Cc: viro@parcelfarce.linux.theplanet.co.uk, linux-kernel@vger.kernel.org Subject: Re: [PATCH 0/6] files: scalable fd management (V4) Message-ID: <20050615121841.GB4845@in.ibm.com> Reply-To: dipankar@in.ibm.com References: <20050614142612.GA4557@in.ibm.com> <20050614130338.70e99074.akpm@osdl.org> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20050614130338.70e99074.akpm@osdl.org> User-Agent: Mutt/1.4.1i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hello Andrew, On Tue, Jun 14, 2005 at 01:03:38PM -0700, Andrew Morton wrote: > Dipankar Sarma wrote: > > tiobench on a 4-way ppc64 system : > > (lockfree) > > Test 2.6.10-vanilla Stdev 2.6.10-fd Stdev > > ------------------------------------------------------------- > > Seqread 1428 32.47 1475.0 29.11 > > We don't seem to have gained anything? I repeated the measurements on ramfs (as opposed to ext2 on ramdisk in the earlier measurement) and I got more consistent results from tiobench : 4(8) way xeon P4 ----------------- (lock-free) Test 2.6.12-rc5 Stdev 2.6.12-rc5-fd Stdev ------------------------------------------------------------- Seqread 1282 18.59 1343.6 26.37 Randread 1517 7 2415 34.27 Seqwrite 702.2 5.27 709.46 5.9 Randwrite 846.86 15.15 919.68 21.4 4-way ppc64 ------------ (lock-free) Test 2.6.12-rc5 Stdev 2.6.12-rc5-fd Stdev ------------------------------------------------------------- Seqread 1549 91.16 1569.6 47.2 Randread 1473.6 25.11 1585.4 69.99 Seqwrite 1096.8 20.03 1136 29.61 Randwrite 1189.6 4.04 1275.2 32.96 Also running Tridge's thread_perf test on ppc64 : 2.6.12-rc5-vanilla -------------------- Running test 'readwrite' with 4 tasks Threads 0.20 +/- 0.02 seconds Processes 0.16 +/- 0.01 seconds 2.6.12-rc5-fd -------------------- Running test 'readwrite' with 4 tasks Threads 0.18 +/- 0.04 seconds Processes 0.16 +/- 0.01 seconds The benefits are huge (upto ~60%) in some cases on x86 primarily due to the atomic operations during acquisition of ->file_lock and cache line bouncing in fast path. ppc64 benefits are modest due to LL/SC based locking, but still statistically significant. Thanks Dipankar