From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752674AbbAWQCS (ORCPT ); Fri, 23 Jan 2015 11:02:18 -0500 Received: from gum.cmpxchg.org ([85.214.110.215]:48951 "EHLO gum.cmpxchg.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751537AbbAWQCP (ORCPT ); Fri, 23 Jan 2015 11:02:15 -0500 Date: Fri, 23 Jan 2015 11:02:04 -0500 From: Johannes Weiner To: Christoph Lameter Cc: Guenter Roeck , akpm@linux-foundation.org, mm-commits@vger.kernel.org, linux-kernel@vger.kernel.org, linux-mm@kvack.org, linux-fsdevel@vger.kernel.org, linux-next@vger.kernel.org, Stephen Rothwell , mhocko@suse.cz Subject: Re: mmotm 2015-01-22-15-04: qemu failure due to 'mm: memcontrol: remove unnecessary soft limit tree node test' Message-ID: <20150123160204.GA32592@phnom.home.cmpxchg.org> References: <54c1822d.RtdGfWPekQVAw8Ly%akpm@linux-foundation.org> <20150123050802.GB22751@roeck-us.net> <20150123141817.GA22926@phnom.home.cmpxchg.org> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On Fri, Jan 23, 2015 at 09:17:44AM -0600, Christoph Lameter wrote: > On Fri, 23 Jan 2015, Johannes Weiner wrote: > > > Is the assumption of this patch wrong? Does the specified node have > > to be online for the fallback to work? > > Nodes that are offline have no control structures allocated and thus > allocations will likely segfault when the address of the controls > structure for the node is accessed. > > If we wanted to prevent that then every allocation would have to add a > check to see if the nodes are online which would impact performance. Okay, that makes sense, thank you. Andrew, can you please drop this patch?