From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id ; Mon, 6 May 2002 08:20:29 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id ; Mon, 6 May 2002 08:20:28 -0400 Received: from snipe.mail.pas.earthlink.net ([207.217.120.62]:17602 "EHLO snipe.prod.itd.earthlink.net") by vger.kernel.org with ESMTP id ; Mon, 6 May 2002 08:20:28 -0400 Date: Mon, 6 May 2002 04:20:05 -0400 To: andrea@suse.de Cc: linux-kernel@vger.kernel.org Subject: Re: O(1) scheduler gives big boost to tbench 192 Message-ID: <20020506042005.A18792@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 > BTW, Randy, I seen my tree runs slower with tiobench, that's probably > because I made the elevator anti-starvation logic more aggressive than > mainline and the other kernel trees (to help interactive usage), could > you try to run tiobench on -aa after elvtune -r 8192 -w 16384 > /dev/hd[abcd] to verify? Thanks for the great benchmarking effort. I will have results on the big machine in a couple days. On the small machine, elvtune increases tiobench sequential reads by 30-50%, and lowers worst case latency a little. More -aa at: http://home.earthlink.net/~rwhron/kernel/aa.html > And for the reason fork is faster in -aa that's partly thanks to the > reschedule-child-first logic, that can be easily merged in mainline, > it's just in 2.5. Is that part of parent_timeslice patch? parent_timeslice helped fork a little when I tried to isolating patches to find what makes fork faster in -aa. It is more than one patch as far as I can tell. On uniprocessor the unixbench execl test, all -aa kernel's going back at least to 2.4.15aa1 are about 20% faster than other trees, even those like jam and akpm's splitted vm. Fork in -aa for more "real world" test (autoconf build) is about 8-10% over other kernel trees. On quad Xeon, with bigger L2 cache, autoconf (fork test) the difference between mainline and -aa is smaller. The -aa based VMs in aa, jam, and mainline have about 15% edge over rmap VM in ac and rmap. jam has a slight advantage for autoconf build, possibly because of O(1) effect which is more likely to show up since more processes execute on the 4 way box. More quad Xeon at: http://home.earthlink.net/~rwhron/kernel/bigbox.html -- Randy Hron