Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755783AbYGOEQS (ORCPT ); Tue, 15 Jul 2008 00:16:18 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751389AbYGOEQK (ORCPT ); Tue, 15 Jul 2008 00:16:10 -0400 Received: from hrndva-omtalb.mail.rr.com ([71.74.56.124]:35892 "EHLO hrndva-omtalb.mail.rr.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750865AbYGOEQJ (ORCPT ); Tue, 15 Jul 2008 00:16:09 -0400 Date: Tue, 15 Jul 2008 00:16:07 -0400 (EDT) From: Steven Rostedt X-X-Sender: rostedt@gandalf.stny.rr.com To: Linus Torvalds cc: Dmitry Adamushko , Vegard Nossum , Paul Menage , Max Krasnyansky , Paul Jackson , Peter Zijlstra , miaox@cn.fujitsu.com, Thomas Gleixner , Ingo Molnar , Linux Kernel Subject: Re: current linux-2.6.git: cpusets completely broken In-Reply-To: Message-ID: References: <20080712031736.GA3040@damson.getinternet.no> 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: 1275 Lines: 31 On Mon, 14 Jul 2008, Linus Torvalds wrote: > > > > Oh, I'm not arguing. My mind is going off to an even bigger picture, where > > something in the future would need to stop migration to a particular CPU, > > and that it could simply clear the bit and call synchronize_sched. The run > > queue lock is only visible to the scheduler. Sorry, I may have been day > > dreaming out loud ;-) > > Well, you'd be stuck right now anyway. > > At least in my trivial patch, the cpu_active_map locking is protected by > 'cpu_add_remove_lock' which is static to cpu.c. The only thing that > modifies it (apart from the initial setup before SMP has been brought up) > is the hotplug code. Yeah, I see that now. I was thinking back to a time I was doing some crazy kernel hacking and would have liked this feature (stop new tasks from migrating to a CPU). cpusets today are probably a better answer, and what I was thinking with using the cpu_active_map is more of a hack. Sorry for the noise, I'll go back to updating ftrace.txt -- Steve -- 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/