From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S267631AbUHEK7m (ORCPT ); Thu, 5 Aug 2004 06:59:42 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S267634AbUHEK6Y (ORCPT ); Thu, 5 Aug 2004 06:58:24 -0400 Received: from mail4.hitachi.co.jp ([133.145.228.5]:15081 "EHLO mail4.hitachi.co.jp") by vger.kernel.org with ESMTP id S267631AbUHEK4s (ORCPT ); Thu, 5 Aug 2004 06:56:48 -0400 Message-ID: <41121265.8000909@sdl.hitachi.co.jp> Date: Thu, 05 Aug 2004 19:56:37 +0900 From: Hideo AOKI Organization: Systems Development Lab., Hitachi, Ltd. User-Agent: Mozilla/5.0 (Windows; U; Windows NT 5.1; ja-JP; rv:1.4) Gecko/20030624 Netscape/7.1 (ax) X-Accept-Language: ja, en-us, en MIME-Version: 1.0 To: Rik van Riel CC: Andrew Morton , linux-kernel@vger.kernel.org Subject: Re: 2.6.8-rc2-mm2 References: <20040802015527.49088944.akpm@osdl.org> In-Reply-To: Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Hi, Rik van Riel wrote: > I would really appreciate any testing results on this, both good > and bad. I want to get this thing tuned and into a generally good > shape for use by everybody upstream. > > I'm especially interested in how this affects compute servers, > desktops and heavily overloaded network servers (the "spamassassin > slowed my system to a crawl" symptom would be one to test ;)). > > I suspect the patch may need some tweaking to help interactivity > in some cases, but maybe it'll already work magically by itself... To evaluate your patch, I tested -mm kernels for thrashing generated by our benchmark suit. In 2.6.8-rc2-mm2, performance of application increased, and overhead of kernel decreased. ** Overview of workload Benchmark program creates disk I/O processes and shared memory access processes. Generating disk I/O and shared memory access at the same time. ** Detailed environment of performance evaluation - Hardware CPU: Xeon 1.6GHz * 4 Memory: 2GB HDD: IDE ATA100 - The benchmark suit The benchmark suit is the wblg-disk, which I have released on SourceForge. # I used alpha version (1.0.3-alpha) in this test. # I will release 1.0.3 soon. - configuration of benchmark 1. disk IO workload + number of process: 4 processes + read/write ratio: read 0% / write 100% + file IO size: 1KB - 256KB (random) 2. memory access workload + number of process: 32 processes + Shard memory regions: 512MB * 4 + Each process accesses one shared memory region. (8 processes share one shared memory region.) + Each process repeats 4 byte memory access each 4KB. Measurement time: 1 hour Measurement items: write throughput - Other configurations Using Oprofile Issue vmstat command each 1 minute ** Results of performance evaluation * result of benchmark write throughput [MB/s] 2.6.8-rc2-mm1: 2.39 2.6.8-rc2-mm2: 2.68 * result of vmstat swap in(kB/s) swap out(kB/s) 2.6.8-rc2-mm1: 0 - 641 0 - 583 2.6.8-rc2-mm2: 0 - 727 0 - 684 * results of Oprofile - System profiling (top 2) Overhead of kernel decreased by 3.9%. 2.6.8-rc2-mm1: No. samples % 1. 170981153 77.6102 wblg-disk_client 2. 46808551 21.2469 vmlinux-2.6.8-rc2-mm1 2.6.8-rc2-mm2: No. samples % 1. 179798682 81.6102 wblg-disk_client 2. 38141112 17.3122 vmlinux-2.6.8-rc2-mm2 - Kernel profiling (top 10) Ratio of page_referenced_one() and kmap_atomic() decreased. 2.6.8-rc2-mm1: No. samples % symbol name 1 11398599 24.3515 page_referenced_one 2 5652276 12.0753 kmap_atomic 3 2257662 4.8232 sysenter_past_esp 4 2098275 4.4827 flush_tlb_others 5 1467288 3.1347 __copy_to_user_ll 6 1167740 2.4947 page_address 7 1145108 2.4464 page_fault 8 946909 2.0229 flush_tlb_page 9 889151 1.8995 do_gettimeofday 10 828174 1.7693 refill_inactive_zone 2.6.8-rc2-mm2: No. samples % symbol name 1 6057840 15.8827 page_referenced_one 2 3707571 9.7207 kmap_atomic 3 2531840 6.6381 sysenter_past_esp 4 1707017 4.4755 __copy_to_user_ll 5 1328610 3.4834 flush_tlb_others 6 1233726 3.2346 page_fault 7 1140917 2.9913 do_gettimeofday 8 970534 2.5446 get_offset_tsc 9 759579 1.9915 mark_offset_tsc 10 650208 1.7047 page_address Best regards, Hideo AOKI Systems Development Laboratory, Hitachi, Ltd.