From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from psmtp.com (na3sys010amx198.postini.com [74.125.245.198]) by kanga.kvack.org (Postfix) with SMTP id 4A1696B002C for ; Fri, 2 Mar 2012 16:21:12 -0500 (EST) Message-ID: <1330723262.11248.233.camel@twins> Subject: Re: [PATCH] cpuset: mm: Remove memory barrier damage from the page allocator From: Peter Zijlstra Date: Fri, 02 Mar 2012 22:21:02 +0100 In-Reply-To: <20120302112358.GA3481@suse.de> References: <20120302112358.GA3481@suse.de> Content-Type: text/plain; charset="ISO-8859-1" Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 Sender: owner-linux-mm@kvack.org List-ID: To: Mel Gorman Cc: Andrew Morton , Miao Xie , Christoph Lameter , linux-mm@kvack.org, linux-kernel@vger.kernel.org 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.=20 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(). -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/ Don't email: email@kvack.org