Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1760870AbXKHCrz (ORCPT ); Wed, 7 Nov 2007 21:47:55 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1760675AbXKHCrM (ORCPT ); Wed, 7 Nov 2007 21:47:12 -0500 Received: from waste.org ([66.93.16.53]:48605 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1760659AbXKHCrK (ORCPT ); Wed, 7 Nov 2007 21:47:10 -0500 Date: Wed, 7 Nov 2007 20:44:26 -0600 From: Matt Mackall To: Andi Kleen Cc: Andrew Morton , Marin Mitov , linux-kernel@vger.kernel.org, Thomas Gleixner , Ingo Molnar Subject: Re: is minimum udelay() not respected in preemptible SMP kernel-2.6.23? Message-ID: <20071108024425.GR19691@waste.org> References: <200711071921.52330.mitov@issp.bas.bg> <200711080131.01243.ak@suse.de> <20071108010347.GP19691@waste.org> <200711080220.59086.ak@suse.de> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <200711080220.59086.ak@suse.de> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 861 Lines: 20 On Thu, Nov 08, 2007 at 02:20:58AM +0100, Andi Kleen wrote: > > > But I think we'd be best off stashing a single bit somewhere and > > checking it at migrate time (relatively infrequent) rather than > > copying and zeroing out a potentially enormous affinity mask every > > time we disable migration (often, and in fast paths). Perhaps adding > > TASK_PINNED to the task state flags would do it? > > It would need to be a count to be able to nest it. Ahh, right. Suppose that means fattening the task struct until someone comes up with something more clever. -- Mathematics is the supreme nostalgia of our time. - 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/