From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S263264AbTDLNCq (for ); Sat, 12 Apr 2003 09:02:46 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S263265AbTDLNCq (for ); Sat, 12 Apr 2003 09:02:46 -0400 Received: from c17870.thoms1.vic.optusnet.com.au ([210.49.248.224]:43137 "EHLO mail.kolivas.org") by vger.kernel.org with ESMTP id S263264AbTDLNCp (for ); Sat, 12 Apr 2003 09:02:45 -0400 From: Con Kolivas To: Eric Wong Subject: Re: 2.4.20-ck5 sucks Date: Sat, 12 Apr 2003 23:16:16 +1000 User-Agent: KMail/1.5.1 Cc: linux-kernel@vger.kernel.org References: <200304121323.25094.kernel@kolivas.org> <20030412124132.GA3187@BL4ST> In-Reply-To: <20030412124132.GA3187@BL4ST> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200304122316.16785.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Sat, 12 Apr 2003 22:41, Eric Wong wrote: > Con Kolivas wrote: > > It seems the interactivity patch wasn't worth the effort, confirming my > > suspicions - which is why I resisted posting it in the first place. > > Yikes! I've been indulging in 2.5.67 + anticipatory I/O for bit now, > back to 2.4... > > I finally got around running ck5 with a lot of other odd patches from > here and there just last night. I wasn't sure if it was ck5 or any > thing else I put in my kernel that caused it, but the scheduler didn't > seem to want to work once physical memory was low. > > There's a pretty serious bug in the ck5 scheduler where things stop > running after physical memory is low. Even if the make World jobs are > cancelled, performance is still sluggish. <---snip--> Eric I appreciate the work you've done for ck5, but this is two discrete problems. The first is the one you describe with the memory killing the scheduler - a serious bug. The second is that the interactivity patch is too slow. It takes up to 5 seconds for xmms skipping (the reference bad program but used everywhere) to stop. When you first start music it skips all over the place and then settles down after a while. This is embarassing considering the machines are >1Ghz cpus and it doesnt happen on p233 with old scheduler. It appears to take less time the higher the Hz is (makes sense I guess) however higher Hz in 2.4 incurs too much overhead under heavy load. This happens even in 2.5 but is a bit more subtle. My concern is that ck6pre without the interactivity addon works better. I've added the more finegrained scheduler timing and the small bugfix but backed out the rest. I don't think the interactivity patch in it's current form is of any use to O(1) 2.4 kernels. I think Zwane and others have demonstrated that this happens in 2.5 as well so it needs some work yet to be better than stock. Con