From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263212AbTJBCq1 (ORCPT ); Wed, 1 Oct 2003 22:46:27 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263214AbTJBCq1 (ORCPT ); Wed, 1 Oct 2003 22:46:27 -0400 Received: from dyn-ctb-203-221-73-10.webone.com.au ([203.221.73.10]:16132 "EHLO chimp.local.net") by vger.kernel.org with ESMTP id S263212AbTJBCqY (ORCPT ); Wed, 1 Oct 2003 22:46:24 -0400 Message-ID: <3F7B915C.9050301@cyberone.com.au> Date: Thu, 02 Oct 2003 12:45:48 +1000 From: Nick Piggin User-Agent: Mozilla/5.0 (X11; U; Linux i686; en-US; rv:1.4) Gecko/20030827 Debian/1.4-3 X-Accept-Language: en MIME-Version: 1.0 To: bill davidsen CC: linux-kernel@vger.kernel.org Subject: Re: Linux 2.6.0-test6 References: <3F77BB2C.7030402@cyberone.com.au> <3F78D866.5070605@cyberone.com.au> 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 bill davidsen wrote: >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. > Oh ok, yeah. It does look like it might need some work to prevent timeslices from getting too small. I'm going to start working on this soon.