From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755637Ab1JXLpV (ORCPT ); Mon, 24 Oct 2011 07:45:21 -0400 Received: from www.linutronix.de ([62.245.132.108]:57708 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755436Ab1JXLpU (ORCPT ); Mon, 24 Oct 2011 07:45:20 -0400 Date: Mon, 24 Oct 2011 13:45:16 +0200 (CEST) From: Thomas Gleixner To: Yong Zhang cc: linux-kernel@vger.kernel.org, linux-rt-users@vger.kernel.org Subject: Re: [RFC] [PATCH -rt 5/5] cpufreq: get rid of get_online_cpus()/put_online_cpus() In-Reply-To: <20111024113056.GA2635@zhy> Message-ID: References: <1318762607-2261-1-git-send-email-yong.zhang0@gmail.com> <1318762607-2261-6-git-send-email-yong.zhang0@gmail.com> <20111024024416.GB24581@zhy> <20111024113056.GA2635@zhy> User-Agent: Alpine 2.02 (LFD 1266 2009-07-14) MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII X-Linutronix-Spam-Score: -1.0 X-Linutronix-Spam-Level: - X-Linutronix-Spam-Status: No , -1.0 points, 5.0 required, ALL_TRUSTED=-1,SHORTCIRCUIT=-0.0001 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, 24 Oct 2011, Yong Zhang wrote: > On Mon, Oct 24, 2011 at 11:24:51AM +0200, Thomas Gleixner wrote: > > > No sure whether it's big issue or not. > > > Mind showing more about your concern? > > > > This is probably not the only place which will run into that issue and > > I have not much interest to patch all those sites. > > If so, I think that kind of violation has been caught in mainline, > because mainline has had CPU_DOWN_PREPARE called under > cpu_hotplug.lock, right? > > Or am I missing something? Hmm, no. I obviously forgot that I moved it in RT :( So yes, it should be safe. Though the question is why cpufreq does not suffer from that that problem in mainline. I'll stare at that code some more. Thanks, tglx