Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757985AbYFDDAJ (ORCPT ); Tue, 3 Jun 2008 23:00:09 -0400 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1752455AbYFDC7z (ORCPT ); Tue, 3 Jun 2008 22:59:55 -0400 Received: from wolverine02.qualcomm.com ([199.106.114.251]:57711 "EHLO wolverine02.qualcomm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752181AbYFDC7y (ORCPT ); Tue, 3 Jun 2008 22:59:54 -0400 X-IronPort-AV: E=McAfee;i="5200,2160,5309"; a="3486852" Message-ID: <4846053C.3090201@qualcomm.com> Date: Tue, 03 Jun 2008 20:00:12 -0700 From: Max Krasnyansky User-Agent: Thunderbird 2.0.0.14 (X11/20080501) MIME-Version: 1.0 To: Nick Piggin CC: Ingo Oeser , Dimitri Sivanich , Peter Zijlstra , Paul Jackson , linux-kernel@vger.kernel.org, Con Kolivas , "Derek L. Fults" , devik , Dinakar Guniguntala , Emmanuel Pacaud , Frederik Deweerdt , Ingo Molnar , Matthew Dobson , rostedt@goodmis.org, Oleg Nesterov , "Paul E. McKenney" , Paul Menage , "Randy.Dunlap" , suresh.b.siddha@intel.com, Thomas Gleixner Subject: Re: Inquiry: Should we remove "isolcpus= kernel boot option? (may have realtime uses) References: <20080601213019.14ea8ef8.pj@sgi.com> <4844BB41.7000605@qualcomm.com> <4845D825.6000403@qualcomm.com> <200806041118.40675.nickpiggin@yahoo.com.au> In-Reply-To: <200806041118.40675.nickpiggin@yahoo.com.au> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1013 Lines: 25 Nick Piggin wrote: > On Wednesday 04 June 2008 09:47, Max Krasnyanskiy wrote: >> Dimitri, you can probably use that too. ie Boot the thing with most CPUs >> offline and then bring them online. That way you'll know for sure that no >> timers, works, hard-/soft-irqs, etc are running on them. > > When you bring a CPU online, in theory the sched domains should get > set up for them, so you should start seeing processes get migrated > onto it, and with them timers work queues etc. > > If you have irqbalanced running, it probably migrates irqs onto them > as well if it needs to. Sure. My suggestion assumes that system wide balancing is disabled (via top level cpuset) and that IRQ affinity masks are properly setup. I mentioned that in my earlier emails. Max -- 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/