From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S932213AbXGKAg6 (ORCPT ); Tue, 10 Jul 2007 20:36:58 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1758324AbXGKAgu (ORCPT ); Tue, 10 Jul 2007 20:36:50 -0400 Received: from waste.org ([66.93.16.53]:46791 "EHLO waste.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752607AbXGKAgt (ORCPT ); Tue, 10 Jul 2007 20:36:49 -0400 Date: Tue, 10 Jul 2007 19:36:12 -0500 From: Matt Mackall To: Nick Piggin Cc: Mathieu Desnoyers , Steven Rostedt , Ingo Molnar , linux-kernel@vger.kernel.org Subject: Re: [RFC] Thread Migration Preemption Message-ID: <20070711003611.GY11115@waste.org> References: <20070705215152.GA4865@Krystal> <468DDD3A.6010308@yahoo.com.au> <20070710233938.GT11166@waste.org> <46941E0F.3040209@yahoo.com.au> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <46941E0F.3040209@yahoo.com.au> User-Agent: Mutt/1.5.13 (2006-08-11) Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org On Wed, Jul 11, 2007 at 10:02:23AM +1000, Nick Piggin wrote: > >I like this patch a lot. Even if we don't add the underlying mechanism > >right now, adding migration_disable as an alias for preempt_disable > >will much better document quite a number of the users. > > I'd have no problem with that, and it might make it easier in future to > justify a more complex scheme. What do you think, Mathieu? Also, small nit: it ought to be migrate_disable to match the form of preempt_disable. > >>The task struct is not something we should just be carefree putting crap > >>into because it is seemingly free :( > > > >Sadly, it is free at the moment. We can only fit 3 task_structs in an > >order-1 SLAB, > >with lots of slop. > > Well apart from more cacheline access, that's why I say seemingly free. But > actually it uses up space we may like for something else in future and/or > makes it harder to shrink down if any effort ever goes into that. Yes, I'm just trying to draw the sad state of task_struct to people's attention. -- Mathematics is the supreme nostalgia of our time.