From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1031031AbXDQAmk (ORCPT ); Mon, 16 Apr 2007 20:42:40 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1031043AbXDQAmk (ORCPT ); Mon, 16 Apr 2007 20:42:40 -0400 Received: from omta01ps.mx.bigpond.com ([144.140.82.153]:53495 "EHLO omta01ps.mx.bigpond.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1031031AbXDQAmj (ORCPT ); Mon, 16 Apr 2007 20:42:39 -0400 Message-ID: <462417F5.2060507@bigpond.net.au> Date: Tue, 17 Apr 2007 10:42:29 +1000 From: Peter Williams User-Agent: Thunderbird 1.5.0.10 (X11/20070302) MIME-Version: 1.0 To: Al Boldi CC: linux-kernel@vger.kernel.org Subject: Re: [Announce] [patch] Modular Scheduler Core and Completely Fair References: <200704150931.42268.a1426z@gawab.com> <200704161342.34498.a1426z@gawab.com> <46237483.6010801@bigpond.net.au> <200704161738.47956.a1426z@gawab.com> In-Reply-To: <200704161738.47956.a1426z@gawab.com> Content-Type: text/plain; charset=ISO-8859-1; format=flowed Content-Transfer-Encoding: 7bit X-Authentication-Info: Submitted using SMTP AUTH PLAIN at oaamta01ps.mx.bigpond.com from [58.164.138.40] using ID pwil3058@bigpond.net.au at Tue, 17 Apr 2007 00:42:34 +0000 Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Al Boldi wrote: > Peter Williams wrote: >> Al Boldi wrote: >>> Reducing the prio-level granularity may also be helpful; >> Because of some of the bit operations code makes it a bad idea to have >> more than 160 priority levels, you're more or less limited to 60 >> priority levels for SCHED_OTHER tasks (as 100 are used for real time) >> and you need 40 of these to pay some attention to niceness leaving you >> about 20 priority levels to use for fiddling. Is that enough? >> >> With spa_ebs (now that CPU rate caps have been removed), you have all 60 >> priorities available for fiddling with as niceness is taken care of when >> calculating each task's entitlement. > > Ok, increasing the number of prio-levels is one thing, but I was more > thinking of reducing the effective difference between each prio-level. For > example, this would allow max_tpt_bonus=18, while the effective range would > be 3, thus reducing granularity. Would this be easily introduceable? OK. Now (I think) I see what you mean. I think that you could achieve this effect by shortening the promotion interval which I think is still one of the tunables. This effectively controls the strength of priority levels -- short promotion intervals weaken and long promotion intervals strengthen the effect of different priority levels. Peter -- Peter Williams pwil3058@bigpond.net.au "Learning, n. The kind of ignorance distinguishing the studious." -- Ambrose Bierce