Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756591AbZCLVqY (ORCPT ); Thu, 12 Mar 2009 17:46:24 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1754516AbZCLVqP (ORCPT ); Thu, 12 Mar 2009 17:46:15 -0400 Received: from www.tglx.de ([62.245.132.106]:50182 "EHLO www.tglx.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754207AbZCLVqO (ORCPT ); Thu, 12 Mar 2009 17:46:14 -0400 Date: Thu, 12 Mar 2009 22:43:40 +0100 (CET) From: Thomas Gleixner To: Darren Hart cc: Arjan van de Ven , Peter Zijlstra , mingo@redhat.com, hpa@zytor.com, linux-kernel@vger.kernel.org, rusty@rustcorp.com.au, mingo@elte.hu, linux-tip-commits@vger.kernel.org Subject: Re: [tip:core/futexes] futex: use current->time_slack_ns for rt tasks too In-Reply-To: <49B97FA8.1060504@us.ibm.com> Message-ID: References: <20090312075559.9856.28822.stgit@Aeon> <49B913DC.6040807@linux.intel.com> <1236866529.22914.3694.camel@twins> <1236869314.22914.3697.camel@twins> <49B923C4.20901@linux.intel.com> <49B97FA8.1060504@us.ibm.com> User-Agent: Alpine 2.00 (LFD 1167 2008-08-23) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1203 Lines: 32 On Thu, 12 Mar 2009, Darren Hart wrote: > Arjan van de Ven wrote: > > Peter Zijlstra wrote: > > > Looking at the default_timer_slack_ns stuff, do we want something like > > > the below? > > > > the original idea was that you had a default slack that you got from exec > > time, > > and then something you could just tweak around yourself independently.... > > > > this would throw that out of the window. > > It seems to me that changing your scheduling class from userspace would be > reasonable justification to change the timer slack to a default value for that > class. Thoughts? We have already five locations in the kernel where we do policy decisions on the slack value for rt-tasks. Such things need to be decided at fork time and modified by scheduler class changes or the prctl interface and not at random places where we need to hand the slack value to the hrtimer code. We just want to use task->timer_slack_ns and be done. Thanks, tglx -- 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/