Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1756071AbcK2QnJ (ORCPT ); Tue, 29 Nov 2016 11:43:09 -0500 Received: from mail.linuxfoundation.org ([140.211.169.12]:51278 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1755801AbcK2QnA (ORCPT ); Tue, 29 Nov 2016 11:43:00 -0500 Subject: Patch "mm, oom: stop pre-mature high-order OOM killer invocations" has been added to the 4.8-stable tree To: mhocko@kernel.org, gregkh@linuxfoundation.org, iamjoonsoo.kim@lge.com, linux-kernel@vger.kernel.org, marc@merlins.org, mhocko@suse.com, stable@vger.kernel.org, tj@kernel.org, torvalds@linux-foundation.org, vbabka@suse.cz Cc: , From: Date: Tue, 29 Nov 2016 17:43:10 +0100 In-Reply-To: <20161129162515.GD9796@dhcp22.suse.cz> Message-ID: <148043779023681@kroah.com> MIME-Version: 1.0 Content-Type: text/plain; charset=ANSI_X3.4-1968 Content-Transfer-Encoding: 8bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2965 Lines: 70 This is a note to let you know that I've just added the patch titled mm, oom: stop pre-mature high-order OOM killer invocations to the 4.8-stable tree which can be found at: http://www.kernel.org/git/?p=linux/kernel/git/stable/stable-queue.git;a=summary The filename of the patch is: mm-oom-stop-pre-mature-high-order-oom-killer-invocations.patch and it can be found in the queue-4.8 subdirectory. If you, or anyone else, feels it should not be added to the stable tree, please let know about it. >From mhocko@kernel.org Tue Nov 29 17:42:17 2016 From: Michal Hocko Date: Tue, 29 Nov 2016 17:25:15 +0100 Subject: mm, oom: stop pre-mature high-order OOM killer invocations To: Greg Kroah-Hartman , Stable tree Cc: Vlastimil Babka , Marc MERLIN , linux-mm@kvack.org, Linus Torvalds , LKML , Joonsoo Kim , Tejun Heo Message-ID: <20161129162515.GD9796@dhcp22.suse.cz> Content-Disposition: inline From: Michal Hocko 31e49bfda184 ("mm, oom: protect !costly allocations some more for !CONFIG_COMPACTION") was an attempt to reduce chances of pre-mature OOM killer invocation for high order requests. It seemed to work for most users just fine but it is far from bullet proof and obviously not sufficient for Marc who has reported pre-mature OOM killer invocations with 4.8 based kernels. 4.9 will all the compaction improvements seems to be behaving much better but that would be too intrusive to backport to 4.8 stable kernels. Instead this patch simply never declares OOM for !costly high order requests. We rely on order-0 requests to do that in case we are really out of memory. Order-0 requests are much more common and so a risk of a livelock without any way forward is highly unlikely. Reported-by: Marc MERLIN Tested-by: Marc MERLIN Signed-off-by: Michal Hocko --- mm/page_alloc.c | 10 ++++++++++ 1 file changed, 10 insertions(+) --- a/mm/page_alloc.c +++ b/mm/page_alloc.c @@ -3161,6 +3161,16 @@ should_compact_retry(struct alloc_contex if (!order || order > PAGE_ALLOC_COSTLY_ORDER) return false; +#ifdef CONFIG_COMPACTION + /* + * This is a gross workaround to compensate a lack of reliable compaction + * operation. We cannot simply go OOM with the current state of the compaction + * code because this can lead to pre mature OOM declaration. + */ + if (order <= PAGE_ALLOC_COSTLY_ORDER) + return true; +#endif + /* * There are setups with compaction disabled which would prefer to loop * inside the allocator rather than hit the oom killer prematurely. Patches currently in stable-queue which might be from mhocko@kernel.org are queue-4.8/mm-oom-stop-pre-mature-high-order-oom-killer-invocations.patch