From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757672Ab2CEUSI (ORCPT ); Mon, 5 Mar 2012 15:18:08 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:59912 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757548Ab2CEUSG (ORCPT ); Mon, 5 Mar 2012 15:18:06 -0500 Date: Mon, 5 Mar 2012 12:18:04 -0800 From: Andrew Morton To: Peter Zijlstra Cc: Mel Gorman , Miao Xie , Christoph Lameter , linux-mm@kvack.org, linux-kernel@vger.kernel.org, Joe Perches Subject: Re: [PATCH] cpuset: mm: Remove memory barrier damage from the page allocator Message-Id: <20120305121804.3b4daed4.akpm@linux-foundation.org> In-Reply-To: <1330723262.11248.233.camel@twins> References: <20120302112358.GA3481@suse.de> <1330723262.11248.233.camel@twins> X-Mailer: Sylpheed 3.0.2 (GTK+ 2.20.1; x86_64-pc-linux-gnu) Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, 02 Mar 2012 22:21:02 +0100 Peter Zijlstra wrote: > On Fri, 2012-03-02 at 11:23 +0000, Mel Gorman wrote: > > For extra style points, the commit introduced the use of yield() in an > > implementation of what looks like a spinning mutex. > > Andrew, could you simply say no to any patch adding a yield()? There's a > 99% chance its a bug, as was this. I'd normally at least poke my tongue out at it - I must have missed this one. > This code would life-lock when cpuset_change_task_nodemask() would be > called by the highest priority FIFO task on UP or when pinned to the > same cpu the task doing get_mems_allowed(). Joe, can we please have a checkpatch rule?