From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754411AbcK1HX1 (ORCPT ); Mon, 28 Nov 2016 02:23:27 -0500 Received: from mail-wm0-f67.google.com ([74.125.82.67]:35257 "EHLO mail-wm0-f67.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754375AbcK1HXT (ORCPT ); Mon, 28 Nov 2016 02:23:19 -0500 Date: Mon, 28 Nov 2016 08:23:15 +0100 From: Michal Hocko To: Marc MERLIN Cc: Vlastimil Babka , Linus Torvalds , linux-mm , LKML , Joonsoo Kim , Tejun Heo , Greg Kroah-Hartman Subject: Re: 4.8.8 kernel trigger OOM killer repeatedly when I have lots of RAM that should be free Message-ID: <20161128072315.GC14788@dhcp22.suse.cz> References: <20161121154336.GD19750@merlins.org> <0d4939f3-869d-6fb8-0914-5f74172f8519@suse.cz> <20161121215639.GF13371@merlins.org> <20161122160629.uzt2u6m75ash4ved@merlins.org> <48061a22-0203-de54-5a44-89773bff1e63@suse.cz> <20161123063410.GB2864@dhcp22.suse.cz> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161123063410.GB2864@dhcp22.suse.cz> User-Agent: Mutt/1.6.0 (2016-04-01) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Marc, could you try this patch please? I think it should be pretty clear it should help you but running it through your use case would be more than welcome before I ask Greg to take this to the 4.8 stable tree. Thanks! On Wed 23-11-16 07:34:10, Michal Hocko wrote: [...] > commit b2ccdcb731b666aa28f86483656c39c5e53828c7 > Author: Michal Hocko > Date: Wed Nov 23 07:26:30 2016 +0100 > > mm, oom: stop pre-mature high-order OOM killer invocations > > 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 > Signed-off-by: Michal Hocko > > diff --git a/mm/page_alloc.c b/mm/page_alloc.c > index a2214c64ed3c..7401e996009a 100644 > --- a/mm/page_alloc.c > +++ b/mm/page_alloc.c > @@ -3161,6 +3161,16 @@ should_compact_retry(struct alloc_context *ac, unsigned int order, int alloc_fla > 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. > -- > Michal Hocko > SUSE Labs -- Michal Hocko SUSE Labs