Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Sat, 30 Mar 2002 13:48:25 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Sat, 30 Mar 2002 13:48:14 -0500 Received: from swan.mail.pas.earthlink.net ([207.217.120.123]:21382 "EHLO swan.prod.itd.earthlink.net") by vger.kernel.org with ESMTP id ; Sat, 30 Mar 2002 13:47:59 -0500 Date: Sat, 30 Mar 2002 13:53:33 -0500 To: linux-kernel@vger.kernel.org Cc: marcelo@conectiva.com.br, akpm@zip.com.au Subject: Linux 2.4.19-pre5 Message-ID: <20020330135333.A16794@rushmore> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline User-Agent: Mutt/1.2.5i From: rwhron@earthlink.net Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org > This release has -aa writeout scheduling changes, which should improve IO > performance (and interactivity under heavy write loads). > _Please_ test that extensively looking for any kind of problems > (performance, interactivity, etc). 2.4.19-pre5 shows a lot of improvement in the tests I run. dbench 128 throughput up over 50% dbench 128 processes 2.4.19-pre4 8.4 **************** 2.4.19-pre5 13.2 ************************** Tiobench sequential writes: 10-20% more throughput and latency is lower. Tiobench Sequential reads Down 7-8%. Andrew Morton's read_latency2 patch improves tiobench sequential reads and writes by 10-35% in the tests I've run. More importantly, read_latency2 drops max latency with 32-128 tiobench threads from 300-600+ seconds down to 2-8 seconds. (2.4.19-pre5 is still unfair to some read requests when threads >= 32) I'm happy with pre5 and hope more chunks of -aa show up in pre6. Maybe Andrew will update read_latency2 for inclusion in pre6. :) It helps tiobench seq writes too. dbench goes down a little though. Max latency is the metric that stands out as "needs improvement" and "fix exists". tiobench seq reads 128 threads MB/s max latency 2.4.19-pre1aa1 6.98 661.3 seconds 2.4.19-pre1aa1rl 9.55 7.8 seconds tiobench seq writes 32 threads MB/s max latency 2.4.19-pre1aa1 15.46 26.1 seconds 2.4.19-pre1aa1rl 17.31 18.0 seconds The read latency issue exists on a 4 way xeon with 4GB ram too. Max latency jumps to 270 seconds with 32 tiobench threads, and is over 500 seconds when threads >= 128. (latency in milliseconds below) Sequential Reads Num Avg Maximum Lat% Lat% Kernel Thr Rate (CPU%) Latency Latency >2s >10s -------------- --- ------------------------------------------------------ 2.4.19-pre5 1 38.46 23.94% 0.302 111.14 0.00000 0.00000 2.4.19-pre5 32 30.24 21.69% 9.883 270391.48 0.01106 0.00915 2.4.19-pre5 64 30.08 21.67% 17.868 357219.21 0.01965 0.01807 2.4.19-pre5 128 30.40 22.77% 30.460 520607.27 0.02714 0.02569 2.4.19-pre5 256 29.07 21.96% 56.444 539381.86 0.05378 0.05197 The behemoth benchmark page: http://home.earthlink.net/~rwhron/kernel/k6-2-475.html -- Randy Hron - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/