Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759763AbZANGDP (ORCPT ); Wed, 14 Jan 2009 01:03:15 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1759269AbZANGCu (ORCPT ); Wed, 14 Jan 2009 01:02:50 -0500 Received: from mail.gmx.net ([213.165.64.20]:34526 "HELO mail.gmx.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with SMTP id S1758895AbZANGCt (ORCPT ); Wed, 14 Jan 2009 01:02:49 -0500 X-Authenticated: #14349625 X-Provags-ID: V01U2FsdGVkX1/f3rxQ0tDf/vUurgJ+hC2LvL87WJe+6E6DB7KxaA bjHA014268ClZ2 Subject: Re: [BUG] How to get real-time priority using idle priority From: Mike Galbraith To: Ingo Molnar Cc: Brian Rogers , linux-kernel@vger.kernel.org, Peter Zijlstra In-Reply-To: <20090114053106.GA10410@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> Content-Type: text/plain Date: Wed, 14 Jan 2009 07:02:45 +0100 Message-Id: <1231912965.956.11.camel@marge.simson.net> Mime-Version: 1.0 X-Mailer: Evolution 2.22.1.1 Content-Transfer-Encoding: 7bit X-Y-GMX-Trusted: 0 X-FuHaFi: 0.61 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2585 Lines: 46 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. I implemented the advance min_vruntime at nice 0 thing, and that seems to work fine. SCHED_IDLE tasks slam right as they execute, but check out how _far_ right they slam. This was with the build pinned to cpu 3, so no migration issues. I'll try weight of 3. cfs_rq[3]: .exec_clock : 0.000000 .MIN_vruntime : 281842722.745713 .min_vruntime : 370490.315434 .max_vruntime : 281843966.887081 .spread : 1244.141368 .spread0 : 85467.080507 .nr_running : 6 .load : 12 .nr_spread_over : 0 rt_rq[3]: .rt_nr_running : 0 .rt_throttled : 0 .rt_time : 0.000000 .rt_runtime : 950.000000 runnable tasks: task PID tree-key switches prio exec-runtime sum-exec sum-sleep ---------------------------------------------------------------------------------------------------------- make 29977 281843914.902150 171 120 0 0 0.000000 0.000000 0.000000 make 30530 281842722.745713 6 120 0 0 0.000000 0.000000 0.000000 gcc 30584 281843921.282161 1 120 0 0 0.000000 0.000000 0.000000 sh 30590 281843966.887081 2 120 0 0 0.000000 0.000000 0.000000 gcc 30591 281843882.274316 1 120 0 0 0.000000 0.000000 0.000000 R cc1 30592 372734.946902 5 120 0 0 0.000000 0.000000 0.000000 -- 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/