Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932615AbVKBHXU (ORCPT ); Wed, 2 Nov 2005 02:23:20 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S932616AbVKBHXU (ORCPT ); Wed, 2 Nov 2005 02:23:20 -0500 Received: from ns.ustc.edu.cn ([202.38.64.1]:28326 "EHLO mx1.ustc.edu.cn") by vger.kernel.org with ESMTP id S932615AbVKBHXT (ORCPT ); Wed, 2 Nov 2005 02:23:19 -0500 Date: Wed, 2 Nov 2005 15:23:15 +0800 From: Wu Fengguang To: Alexandre Cassen Cc: Ram Pai , linux-kernel@vger.kernel.org, Andrew Morton , slpratt@us.ibm.com, Con Kolivas , Folkert van Heusden Subject: Re: [PATCH 2.6.14] Adaptive read-ahead V6 Message-ID: <20051102072315.GB4072@mail.ustc.edu.cn> Mail-Followup-To: Wu Fengguang , Alexandre Cassen , Ram Pai , linux-kernel@vger.kernel.org, Andrew Morton , slpratt@us.ibm.com, Con Kolivas , Folkert van Heusden References: <20051101134925.GA5576@mail.ustc.edu.cn> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.9i Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 5449 Lines: 71 Hi, Alexandre, On Tue, Nov 01, 2005 at 09:55:10PM +0100, Alexandre Cassen wrote: > I just replayed a benchmark with your new patch. You will find attached > new bench output. > > Experiment Protocol: . 10 mpeg2 video bit/rate=3.5Mb/s ATM > . around 4Mb/s ip+udp per stream > . Linux Kernel 2.6.14 + your v6 patch > . stored on a raid0 /dev/md0 - XFS > . blockdev --setra 2048 /dev/md0 > . 6GB RAM + 2*GiGE NICs Trunk + > 2*36GB HDD on a U320 adaptec controler > . R-A LOOKAHEAD_RATIO=4 > . ADP R-A /proc/sys/vm/readahead_ratio=200 > . Lauch video at true random positions > > I launched 20 clients per video, say 200 streams. I collected infos during > around 1hours running. > > Let me know if you want some more inputs. Thanks. > [table requests] total newfile state context contexta backward onthrash onraseek none > cache_miss 2847 6 1525 694 0 0 0 4 618 > read_random 295 2 3 2 0 0 0 0 288 > io_congestion 0 0 0 0 0 0 0 0 0 > io_cache_hit 7420 3 5941 1472 0 0 0 4 0 > io_block 4159 807 36 2648 0 0 0 4 664 This reflects times of IO delays. The main delays(2648) occur in context method, which are triggered by cache misses(2847). The cache misses might be caused by canceled look-ahead marks due to cache hits. I'll try fixing it. > readahead 116568 801 113031 2731 1 0 0 4 0 > lookahead 115904 223 112954 2726 1 0 0 0 0 > lookahead_hit 113376 31 111256 2072 1 0 0 0 16 > readahead_eof 660 578 77 5 0 0 0 0 0 > readahead_shrink 0 0 0 0 0 0 0 0 0 > readahead_thrash 0 0 0 0 0 0 0 0 0 > readahead_rescue 18517 0 0 0 0 0 0 0 18517 > > [table pages] total newfile state context contexta backward onthrash onraseek none > cache_miss 5452 6 3037 1377 0 0 0 7 1025 > read_random 391 2 5 2 0 0 0 0 382 > io_congestion 0 0 0 0 0 0 0 0 0 > io_cache_hit 622587 4 386637 235281 0 0 0 665 0 > io_block 547948 1954 1443 542863 0 0 0 1024 664 > readahead 28748734 1959 28414048 332302 66 0 0 359 0 > readahead_hit 28830698 1764 28414032 412507 3 0 0 856 1536 > lookahead 29202363 448 28780361 421521 33 0 0 0 0 > lookahead_hit 28671617 64 28358286 313232 35 0 0 0 0 > readahead_eof 15225 1065 13458 702 0 0 0 0 0 > readahead_shrink 0 0 0 0 0 0 0 0 0 > readahead_thrash 0 0 0 0 0 0 0 0 0 > readahead_rescue 265680 0 0 0 0 0 0 0 265680 Your system is memory bounty and thrashing free. The ~1G rescued pages are expected to be saved for a following reader. > > [table summary] total newfile state context contexta backward onthrash onraseek none > random_rate 0% 0% 0% 0% 0% 0% 0% 0% 99% > ra_hit_rate 100% 90% 99% 124% 4% 0% 0% 237% 153600% > la_hit_rate 97% 13% 98% 75% 50% 0% 0% 0% 1600% > avg_ra_size 247 2 251 122 33 0 0 72 0 > avg_la_size 252 2 255 155 16 0 0 0 0 Regards, Wu Fengguang - 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/