From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S264894AbTLWCnt (ORCPT ); Mon, 22 Dec 2003 21:43:49 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S264902AbTLWCnt (ORCPT ); Mon, 22 Dec 2003 21:43:49 -0500 Received: from c211-28-147-198.thoms1.vic.optusnet.com.au ([211.28.147.198]:33487 "EHLO mail.kolivas.org") by vger.kernel.org with ESMTP id S264894AbTLWCnB (ORCPT ); Mon, 22 Dec 2003 21:43:01 -0500 From: Con Kolivas To: Nick Piggin Subject: Re: [PATCH] 2.6.0 batch scheduling, HT aware Date: Tue, 23 Dec 2003 13:42:56 +1100 User-Agent: KMail/1.5.3 Cc: "Nakajima, Jun" , linux kernel mailing list References: <200312231138.21734.kernel@kolivas.org> <200312231224.49069.kernel@kolivas.org> <3FE79C32.6050104@cyberone.com.au> In-Reply-To: <3FE79C32.6050104@cyberone.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Content-Disposition: inline Message-Id: <200312231342.56724.kernel@kolivas.org> Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Tue, 23 Dec 2003 12:36, Nick Piggin wrote: > Con Kolivas wrote: > >On Tue, 23 Dec 2003 12:11, Nick Piggin wrote: > >>I think this patch is much too ugly to get into such an elegant > >> scheduler. No fault to you Con because its an ugly problem. > > > >You're too kind. No it's ugly because of my code but it works for now. > > Well its all the special cases for batch scheduling that I don't like, > the idea to not run batch tasks on a package running non batch processes > is sound. I thought the batch scheduling code is Ingo's, but I could > be mistaken. Anyway... I realise the special cases suck. Code for one setting in a spot where it affects everyone is bad. Regarding the batch scheduling; no that's my special flavour coded ugly from the ground up. Ingo's is much smarter than this but once again I needed something that works now without too much effort. > > >>How about this: if a task is "delta" priority points below a task running > >>on another sibling, move it to that sibling (so priorities via timeslice > >>start working). I call it active unbalancing! I might be able to make it > >>fit if there is interest. Other suggestions? > > > >I discussed this with Ingo and that's the sort of thing we thought of. > > Perhaps a relative crossover of 10 dynamic priorities and an absolute > > crossover of 5 static priorities before things got queued together. This > > is really only required for the UP HT case. > > Well I guess it would still be nice for "SMP HT" as well. Hopefully the > code can be generic enough that it would just carry over nicely. I disagree. I can't think of a real world scenario where 2+ physical cpus would benefit from this. > It does > have complications though because the load balancer would have to be taught > about it, and those architectures that do hardware priorities probably > don't even want it. Probably the simple relative/absolute will have to suffice. However it still doesn't help the fact that running something cpu bound concurrently at nice 0 with something interactive nice 0 is actually slower if you use a UP HT processor in SMP mode instead of UP. Con