From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755916AbbAWRAa (ORCPT ); Fri, 23 Jan 2015 12:00:30 -0500 Received: from bh-25.webhostbox.net ([208.91.199.152]:40119 "EHLO bh-25.webhostbox.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755791AbbAWRAX (ORCPT ); Fri, 23 Jan 2015 12:00:23 -0500 Message-ID: <54C27E07.6000908@roeck-us.net> Date: Fri, 23 Jan 2015 08:59:51 -0800 From: Guenter Roeck User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.4.0 MIME-Version: 1.0 To: Johannes Weiner , Christoph Lameter CC: 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' References: <54c1822d.RtdGfWPekQVAw8Ly%akpm@linux-foundation.org> <20150123050802.GB22751@roeck-us.net> <20150123141817.GA22926@phnom.home.cmpxchg.org> <20150123160204.GA32592@phnom.home.cmpxchg.org> In-Reply-To: <20150123160204.GA32592@phnom.home.cmpxchg.org> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-Authenticated_sender: linux@roeck-us.net X-OutGoing-Spam-Status: No, score=-1.0 X-CTCH-PVer: 0000001 X-CTCH-Spam: Unknown X-CTCH-VOD: Unknown X-CTCH-Flags: 0 X-CTCH-RefID: str=0001.0A020201.54C27E27.00DF,ss=1,re=0.001,recu=0.000,reip=0.000,cl=1,cld=1,fgs=0 X-CTCH-Score: 0.001 X-CTCH-ScoreCust: 0.000 X-CTCH-Rules: C_4847, X-CTCH-SenderID: linux@roeck-us.net X-CTCH-SenderID-Flags: 0 X-CTCH-SenderID-TotalMessages: 6 X-CTCH-SenderID-TotalSpam: 0 X-CTCH-SenderID-TotalSuspected: 0 X-CTCH-SenderID-TotalConfirmed: 0 X-CTCH-SenderID-TotalBulk: 0 X-CTCH-SenderID-TotalVirus: 0 X-CTCH-SenderID-TotalRecipients: 0 X-AntiAbuse: This header was added to track abuse, please include it with any abuse report X-AntiAbuse: Primary Hostname - bh-25.webhostbox.net X-AntiAbuse: Original Domain - vger.kernel.org X-AntiAbuse: Originator/Caller UID/GID - [47 12] / [47 12] X-AntiAbuse: Sender Address Domain - roeck-us.net X-Get-Message-Sender-Via: bh-25.webhostbox.net: mailgid no entry from get_relayhosts_entry X-Source: X-Source-Args: X-Source-Dir: Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 01/23/2015 08:02 AM, Johannes Weiner wrote: > 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? > Problem is that there are three patches. 2537ffb mm: memcontrol: consolidate swap controller code 2f9b346 mm: memcontrol: consolidate memory controller initialization a40d0d2 mm: memcontrol: remove unnecessary soft limit tree node test Reverting (or dropping) a40d0d2 alone is not possible since it modifies mem_cgroup_soft_limit_tree_init which is removed by 2f9b346. Guenter