From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756891Ab0EaKBT (ORCPT ); Mon, 31 May 2010 06:01:19 -0400 Received: from bombadil.infradead.org ([18.85.46.34]:48356 "EHLO bombadil.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751861Ab0EaKBR convert rfc822-to-8bit (ORCPT ); Mon, 31 May 2010 06:01:17 -0400 Subject: Re: [PATCH 2/4] sched: implement __set_cpus_allowed() From: Peter Zijlstra To: Tejun Heo Cc: mingo@elte.hu, linux-kernel@vger.kernel.org, Rusty Russell , Mike Galbraith In-Reply-To: <4C03879A.8030505@kernel.org> References: <1273747705-7829-1-git-send-email-tj@kernel.org> <1273747705-7829-3-git-send-email-tj@kernel.org> <1275292866.27810.21441.camel@twins> <4C03879A.8030505@kernel.org> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: 8BIT Date: Mon, 31 May 2010 12:01:24 +0200 Message-ID: <1275300084.27810.21850.camel@twins> Mime-Version: 1.0 X-Mailer: Evolution 2.28.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 2010-05-31 at 11:55 +0200, Tejun Heo wrote: > I don't think flushing from CPU_UP_PREPARE would be a good idea. > There is no guarantee that those works will finish in short (human > scale) time, If not, we should cure it by ensuring these works won't be left lingering I think. Also, I really don't much care about how fast we can hotplug cycle things -- its an utter slow path. > but we can update cpu_active mask before other > CPU_UP_PREPARE notifiers are executed so that it's symmetrical to cpu > down path and then this problem goes away the exact same way, right? Ah, no, we cannot mark it active before its actually up, because at that time we'll actually try and run stuff on it, which clearly won't work when its not there to run stuff.