From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755486AbaIZPou (ORCPT ); Fri, 26 Sep 2014 11:44:50 -0400 Received: from resqmta-ch2-01v.sys.comcast.net ([69.252.207.33]:44897 "EHLO resqmta-ch2-01v.sys.comcast.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754127AbaIZPot (ORCPT ); Fri, 26 Sep 2014 11:44:49 -0400 Date: Fri, 26 Sep 2014 10:44:47 -0500 (CDT) From: Christoph Lameter X-X-Sender: cl@gentwo.org To: Vladimir Davydov cc: linux-kernel@vger.kernel.org, Li Zefan , Pekka Enberg , David Rientjes , Joonsoo Kim , Andrew Morton , linux-mm@kvack.org Subject: Re: [PATCH 1/4] cpuset: convert callback_mutex to a spinlock In-Reply-To: <778e648ce62511c7aff225ca067e0abedb247f25.1411741632.git.vdavydov@parallels.com> Message-ID: References: <778e648ce62511c7aff225ca067e0abedb247f25.1411741632.git.vdavydov@parallels.com> 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 Fri, 26 Sep 2014, Vladimir Davydov wrote: > The callback_mutex is only used to synchronize reads/updates of cpusets' > flags and cpu/node masks. These operations should always proceed fast so > there's no reason why we can't use a spinlock instead of the mutex. Checked that and given the other restrictions already on the use of callback_mutex this is to be expected. Acked-by: Christoph Lameter