From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1030235AbeEYUu0 (ORCPT ); Fri, 25 May 2018 16:50:26 -0400 Received: from mx2.suse.de ([195.135.220.15]:45253 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S968275AbeEYUuZ (ORCPT ); Fri, 25 May 2018 16:50:25 -0400 Subject: Re: [PATCH] mm, page_alloc: do not break __GFP_THISNODE by zonelist reset To: Andrew Morton Cc: linux-mm@kvack.org, linux-kernel@vger.kernel.org, Mel Gorman , Michal Hocko , David Rientjes , Joonsoo Kim , stable@vger.kernel.org References: <20180525130853.13915-1-vbabka@suse.cz> <20180525124300.964a1a15d953e8972625bb0f@linux-foundation.org> From: Vlastimil Babka Message-ID: <4cd73f77-e6ab-bdd1-69a2-bd0f8413d189@suse.cz> Date: Fri, 25 May 2018 22:48:16 +0200 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:52.0) Gecko/20100101 Thunderbird/52.7.0 MIME-Version: 1.0 In-Reply-To: <20180525124300.964a1a15d953e8972625bb0f@linux-foundation.org> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 05/25/2018 09:43 PM, Andrew Morton wrote: > On Fri, 25 May 2018 15:08:53 +0200 Vlastimil Babka wrote: > >> we might consider this for 4.17 although I don't know if there's anything >> currently broken. Stable backports should be more important, but will have to >> be reviewed carefully, as the code went through many changes. >> BTW I think that also the ac->preferred_zoneref reset is currently useless if >> we don't also reset ac->nodemask from a mempolicy to NULL first (which we >> probably should for the OOM victims etc?), but I would leave that for a >> separate patch. > > Confused. If nothing is currently broken then why is a backport > needed? Presumably because we expect breakage in the future? Can you > expand on this? I mean that SLAB is currently not affected, but in older kernels than 4.7 that don't yet have 511e3a058812 ("mm/slab: make cache_grow() handle the page allocated on arbitrary node") it is. That's at least 4.4 LTS. Older ones I'll have to check.