From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755388Ab1JXLbO (ORCPT ); Mon, 24 Oct 2011 07:31:14 -0400 Received: from mail-pz0-f42.google.com ([209.85.210.42]:38649 "EHLO mail-pz0-f42.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754942Ab1JXLbN (ORCPT ); Mon, 24 Oct 2011 07:31:13 -0400 Date: Mon, 24 Oct 2011 19:30:56 +0800 From: Yong Zhang To: Thomas Gleixner 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() Message-ID: <20111024113056.GA2635@zhy> Reply-To: Yong Zhang References: <1318762607-2261-1-git-send-email-yong.zhang0@gmail.com> <1318762607-2261-6-git-send-email-yong.zhang0@gmail.com> <20111024024416.GB24581@zhy> MIME-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Disposition: inline In-Reply-To: User-Agent: Mutt/1.5.20 (2009-06-14) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Oct 24, 2011 at 11:24:51AM +0200, Thomas Gleixner wrote: > > > On Mon, 24 Oct 2011, Yong Zhang wrote: > > > On Wed, Oct 19, 2011 at 11:12:20AM +0200, Thomas Gleixner wrote: > > > On Sun, 16 Oct 2011, Yong Zhang wrote: > > > > > > > Fix below false positive (seems this is not a real deadlock scenario) > > > > lockdep warning: > > > > > > This looks like you caused it with patch 1. > > > > Hmmm, yup. > > CPU_DOWN_PREPARE will be under cpu_hotplug.lock. > > > > > Both need a bit more > > > thought, but thanks for catching that. > > > > 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? Thanks, Yong