From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751384AbdJEMjC (ORCPT ); Thu, 5 Oct 2017 08:39:02 -0400 Received: from Galois.linutronix.de ([146.0.238.70]:33579 "EHLO Galois.linutronix.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751280AbdJEMjB (ORCPT ); Thu, 5 Oct 2017 08:39:01 -0400 Date: Thu, 5 Oct 2017 14:38:55 +0200 (CEST) From: Thomas Gleixner To: Thiago Jung Bauermann cc: linuxppc-dev@lists.ozlabs.org, linux-kernel@vger.kernel.org, Michael Ellerman , Daniel Black Subject: Re: [PATCH] powerpc: Drop lockdep_assert_cpus_held call from arch_update_cpu_topology In-Reply-To: <20171005000430.8080-1-bauerman@linux.vnet.ibm.com> Message-ID: References: <20171005000430.8080-1-bauerman@linux.vnet.ibm.com> User-Agent: Alpine 2.20 (DEB 67 2015-01-07) 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 On Wed, 4 Oct 2017, Thiago Jung Bauermann wrote: > It turns out that not all paths calling arch_update_cpu_topology hold > cpu_hotplug_lock, but that's ok because those paths aren't supposed to race > with any concurrent hotplug events. > > Callers of arch_update_cpu_topology are expected to know what they are > doing when they call the function without holding the lock, so remove the > lockdep warning. "Expected to know what they are doing" is not really a good approach as it's way too simple to screw things up. You might consider to have two functions where one does the check and the other does not, but I leave that to the PPC maintainers. Thanks, tglx