Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759938AbZANHgE (ORCPT ); Wed, 14 Jan 2009 02:36:04 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759468AbZANHfr (ORCPT ); Wed, 14 Jan 2009 02:35:47 -0500 Received: from mx2.mail.elte.hu ([157.181.151.9]:44820 "EHLO mx2.mail.elte.hu" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754873AbZANHfq (ORCPT ); Wed, 14 Jan 2009 02:35:46 -0500 Date: Wed, 14 Jan 2009 08:35:30 +0100 From: Ingo Molnar To: Mike Galbraith Cc: Brian Rogers , linux-kernel@vger.kernel.org, Peter Zijlstra Subject: Re: [BUG] How to get real-time priority using idle priority Message-ID: <20090114073530.GA15644@elte.hu> References: <4969D0D7.2060401@xyzw.org> <1231736941.6003.7.camel@marge.simson.net> <1231765433.5789.35.camel@marge.simson.net> <20090112131406.GB670@elte.hu> <496BE8F6.1040308@xyzw.org> <1231815523.5899.7.camel@marge.simson.net> <1231910014.610.14.camel@marge.simson.net> <20090114053106.GA10410@elte.hu> <1231912965.956.11.camel@marge.simson.net> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <1231912965.956.11.camel@marge.simson.net> User-Agent: Mutt/1.5.18 (2008-05-17) X-ELTE-VirusStatus: clean X-ELTE-SpamScore: -1.5 X-ELTE-SpamLevel: X-ELTE-SpamCheck: no X-ELTE-SpamVersion: ELTE 2.0 X-ELTE-SpamCheck-Details: score=-1.5 required=5.9 tests=BAYES_00 autolearn=no SpamAssassin version=3.2.3 -1.5 BAYES_00 BODY: Bayesian spam probability is 0 to 1% [score: 0.0000] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 698 Lines: 19 * Mike Galbraith wrote: > On Wed, 2009-01-14 at 06:31 +0100, Ingo Molnar wrote: > > What about increasing the weight of SCHED_IDLE tasks from 1 to 2 or 3? > > That still makes them mega-nice (which is more than enough), but should > > make the math a lot less borderline. > > The weight is currently 2, inv_weight is 1 << 31, which is correct. then move it up to 5 or so perhaps? We are hitting limits of 64-bit math here. Ingo -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/