Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754413AbcLZS5O (ORCPT ); Mon, 26 Dec 2016 13:57:14 -0500 Received: from celine.tisys.org ([85.25.117.166]:56568 "EHLO celine.tisys.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750738AbcLZS5L (ORCPT ); Mon, 26 Dec 2016 13:57:11 -0500 Date: Mon, 26 Dec 2016 19:57:03 +0100 From: Nils Holland To: Michal Hocko 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: <20161226185701.GA17030@boerne.fritz.box> References: <20161221073658.GC16502@dhcp22.suse.cz> <20161222101028.GA11105@ppc-nas.fritz.box> <20161222191719.GA19898@dhcp22.suse.cz> <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161226124839.GB20715@dhcp22.suse.cz> User-Agent: Mutt/1.7.2 (2016-11-26) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1864 Lines: 37 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! Greetings Nils