Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754360AbcL0L2F (ORCPT ); Tue, 27 Dec 2016 06:28:05 -0500 Received: from mx2.suse.de ([195.135.220.15]:57728 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753384AbcL0L16 (ORCPT ); Tue, 27 Dec 2016 06:27:58 -0500 Date: Tue, 27 Dec 2016 12:27:53 +0100 From: Michal Hocko To: Nils Holland Cc: Mel Gorman , Johannes Weiner , Vladimir Davydov , Tetsuo Handa , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Chris Mason , David Sterba , linux-btrfs@vger.kernel.org Subject: Re: [RFC PATCH] mm, memcg: fix (Re: OOM: Better, but still there on) Message-ID: <20161227112753.GF1308@dhcp22.suse.cz> References: <20161222214611.GA3015@boerne.fritz.box> <20161223105157.GB23109@dhcp22.suse.cz> <20161223121851.GA27413@ppc-nas.fritz.box> <20161223125728.GE23109@dhcp22.suse.cz> <20161223144738.GB23117@dhcp22.suse.cz> <20161223222559.GA5568@teela.multi.box> <20161226124839.GB20715@dhcp22.suse.cz> <20161226185701.GA17030@boerne.fritz.box> <20161227080837.GA1308@dhcp22.suse.cz> <20161227112313.GA23101@boerne.fritz.box> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161227112313.GA23101@boerne.fritz.box> 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 Content-Length: 2642 Lines: 51 On Tue 27-12-16 12:23:13, Nils Holland wrote: > On Tue, Dec 27, 2016 at 09:08:38AM +0100, Michal Hocko wrote: > > On Mon 26-12-16 19:57:03, Nils Holland wrote: > > > On Mon, Dec 26, 2016 at 01:48:40PM +0100, Michal Hocko wrote: > > > > On Fri 23-12-16 23:26:00, Nils Holland wrote: > > > > > On Fri, Dec 23, 2016 at 03:47:39PM +0100, Michal Hocko wrote: > > > > > > > > > > > > Nils, even though this is still highly experimental, could you give it a > > > > > > try please? > > > > > > > > > > Yes, no problem! So I kept the very first patch you sent but had to > > > > > revert the latest version of the debugging patch (the one in > > > > > which you added the "mm_vmscan_inactive_list_is_low" event) because > > > > > otherwise the patch you just sent wouldn't apply. Then I rebooted with > > > > > memory cgroups enabled again, and the first thing that strikes the eye > > > > > is that I get this during boot: > > > > > > > > > > [ 1.568174] ------------[ cut here ]------------ > > > > > [ 1.568327] WARNING: CPU: 0 PID: 1 at mm/memcontrol.c:1032 mem_cgroup_update_lru_size+0x118/0x130 > > > > > [ 1.568543] mem_cgroup_update_lru_size(f4406400, 2, 1): lru_size 0 but not empty > > > > > > > > Ohh, I can see what is wrong! a) there is a bug in the accounting in > > > > my patch (I double account) and b) the detection for the empty list > > > > cannot work after my change because per node zone will not match per > > > > zone statistics. The updated patch is below. So I hope my brain already > > > > works after it's been mostly off last few days... > > > > > > I tried the updated patch, and I can confirm that the warning during > > > boot is gone. Also, I've tried my ordinary procedure to reproduce my > > > testcase, and I can say that a kernel with this new patch also works > > > fine and doesn't produce OOMs or similar issues. > > > > > > I had the previous version of the patch in use on a machine non-stop > > > for the last few days during normal day-to-day workloads and didn't > > > notice any issues. Now I'll keep a machine running during the next few > > > days with this patch, and in case I notice something that doesn't look > > > normal, I'll of course report back! > > > > Thanks for your testing! Can I add your > > Tested-by: Nils Holland > > Yes, I think so! The patch has now been running for 16 hours on my two > machines, and that's an uptime that was hard to achieve since 4.8 for > me. ;-) So my tests clearly suggest that the patch is good! :-) OK, thanks a lot for your testing! I will wait few more days before I send it to Andrew. -- Michal Hocko SUSE Labs