From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753538AbaKJQRB (ORCPT ); Mon, 10 Nov 2014 11:17:01 -0500 Received: from casper.infradead.org ([85.118.1.10]:59387 "EHLO casper.infradead.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751270AbaKJQQ6 (ORCPT ); Mon, 10 Nov 2014 11:16:58 -0500 Date: Mon, 10 Nov 2014 17:16:56 +0100 From: Peter Zijlstra To: Sasha Levin Cc: Kirill Tkhai , linux-kernel@vger.kernel.org, Oleg Nesterov , Ingo Molnar , Vladimir Davydov , Kirill Tkhai Subject: Re: [PATCH v4] sched/numa: fix unsafe get_task_struct() in task_numa_assign() Message-ID: <20141110161656.GC10501@worktop.programming.kicks-ass.net> References: <1413962231.19914.130.camel@tkhai> <545D928B.2070508@oracle.com> <20141110160320.GA10501@worktop.programming.kicks-ass.net> <5460E339.5020308@oracle.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <5460E339.5020308@oracle.com> User-Agent: Mutt/1.5.22.1 (2013-10-16) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Mon, Nov 10, 2014 at 11:09:29AM -0500, Sasha Levin wrote: > On 11/10/2014 11:03 AM, Peter Zijlstra wrote: > > On Fri, Nov 07, 2014 at 10:48:27PM -0500, Sasha Levin wrote: > >> [ 829.539183] BUG: spinlock recursion on CPU#10, trinity-c594/11067 > >> [ 829.539203] lock: 0xffff880631dd6b80, .magic: dead4ead, .owner: trinity-c594/11067, .owner_cpu: 13 > > > > Ooh, look at that. CPU#10 vs .owner_cpu: 13 on the _same_ task. > > > > One of those again :/ > > Hum. I missed that one. > > Hold on, but the magic here is fine and the owner pointer is fine, why would just the owner cpu > be wrong? I've no clue, but I've seen them before. Complete mystery that.