From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S262582AbTJAVYl (ORCPT ); Wed, 1 Oct 2003 17:24:41 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S262497AbTJAVYl (ORCPT ); Wed, 1 Oct 2003 17:24:41 -0400 Received: from tmr-02.dsl.thebiz.net ([216.238.38.204]:44809 "EHLO gatekeeper.tmr.com") by vger.kernel.org with ESMTP id S262582AbTJAVXZ (ORCPT ); Wed, 1 Oct 2003 17:23:25 -0400 To: linux-kernel@vger.kernel.org Path: gatekeeper.tmr.com!davidsen From: davidsen@tmr.com (bill davidsen) Newsgroups: mail.linux-kernel Subject: Re: Linux 2.6.0-test6 Date: 1 Oct 2003 21:13:54 GMT Organization: TMR Associates, Schenectady NY Message-ID: References: <3F77BB2C.7030402@cyberone.com.au> <3F78D866.5070605@cyberone.com.au> X-Trace: gatekeeper.tmr.com 1065042834 19587 192.168.12.62 (1 Oct 2003 21:13:54 GMT) X-Complaints-To: abuse@tmr.com Originator: davidsen@gatekeeper.tmr.com Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org In article <3F78D866.5070605@cyberone.com.au>, Nick Piggin wrote: | | | bill davidsen wrote: | | >In article <3F77BB2C.7030402@cyberone.com.au>, | >Nick Piggin wrote: | > | >| AFAIK, Con's scheduler doesn't change the nice implementation at all. | >| Possibly some of his changes amplify its problems, or, more likely they | >| remove most other scheduler problems leaving this one noticable. | >| | >| If X is running at -20, and xmms at +19, xmms is supposed to still get | >| 5% of the CPU. Should be enough to run fine. Unfortunately this is | >| achieved by giving X very large timeslices, so xmms's scheduling latency | >| becomes large. The interactivity bonuses don't help, either. | > | >Clearly the "some is good, more is better" approach doesn't provide | >stable balance between sound and cpu hogs. It isn't a question of "how | >much" cpu, just "when"which works or not. | > | >This is sort of like the deadline scheduler in that it trades of | >throughput for avoiding jackpot cases. I think that's desired behaviour | >in a CPU schedular too, at least if used by humans. | > | | I'm not sure what you mean. There is nothing good to say about Ingo's | nice mechanism though (sorry Ingo, its otherwise a very nice | scheduler!). Oh, I think the test5-mm4 behaviour is far better than yours in terms of throughput. I would expect that it could have several percent less system time, leaving it for cpu-bound user processes. However, on my little test machine (PII-350 w/ 96MB) running patch to get a kernel source tree ready makes the system damn near unusable. With your v15 patch neither patch nor a kernel build is a real problem (I don't use -j, there's only one processor and it doesn't help). I can happily read mail, run windows to remote machines to do admin, check web based monitors, and generally use the system. It's not a ball of fire, but it's old and slow moving, and I can identify with that ;-) | In my scheduler, nice -20 processes get small timeslices so scheduling | latency stays low or even gets lower, while nice +19 ones get large | timeslices for lower context switches and better cache efficiency. As | you would like. Clearly your timeslices don't get so large the system suffers. And I can run setiathome with a little nice, like -5, and it will get some time without slowing the important stuff on the system. Even at -19 it does keep going. On a small memory machine I hate to give pages to a process without giving it the CPU to justify the memory. I'm going to try test5-n15 against test5-mm4 and test6-std with a server load, but for now I run your patch on machines I use as personal workstations. I haven't tried it SMP, that day will come. -- bill davidsen CTO, TMR Associates, Inc Doing interesting things with little computers since 1979.