From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx2.suse.de ([195.135.220.15]:46152 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750830AbcL3KTa (ORCPT ); Fri, 30 Dec 2016 05:19:30 -0500 Date: Fri, 30 Dec 2016 10:19:26 +0000 From: Mel Gorman To: Michal Hocko Cc: Nils Holland , 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: <20161230101926.jjjw76negqcvyaim@suse.de> 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=iso-8859-15 In-Reply-To: <20161226124839.GB20715@dhcp22.suse.cz> Sender: linux-btrfs-owner@vger.kernel.org List-ID: 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... > --- > From 397adf46917b2d9493180354a7b0182aee280a8b Mon Sep 17 00:00:00 2001 > From: Michal Hocko > Date: Fri, 23 Dec 2016 15:11:54 +0100 > Subject: [PATCH] mm, memcg: fix the active list aging for lowmem requests when > memcg is enabled > > Nils Holland has reported unexpected OOM killer invocations with 32b > kernel starting with 4.8 kernels > I think it's unfortunate that per-zone stats are reintroduced to the memcg structure. I can't help but think that it would have also worked to always rotate a small number of pages if !inactive_list_is_low and reclaiming for memcg even if it distorted page aging. However, given that such an approach would be less robust and this has been heavily tested; Acked-by: Mel Gorman -- Mel Gorman SUSE Labs From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-wj0-f198.google.com (mail-wj0-f198.google.com [209.85.210.198]) by kanga.kvack.org (Postfix) with ESMTP id BBEAF6B0038 for ; Fri, 30 Dec 2016 05:19:30 -0500 (EST) Received: by mail-wj0-f198.google.com with SMTP id hb5so97923890wjc.2 for ; Fri, 30 Dec 2016 02:19:30 -0800 (PST) Received: from mx2.suse.de (mx2.suse.de. [195.135.220.15]) by mx.google.com with ESMTPS id 4si36719634wjg.34.2016.12.30.02.19.29 for (version=TLS1 cipher=AES128-SHA bits=128/128); Fri, 30 Dec 2016 02:19:29 -0800 (PST) Date: Fri, 30 Dec 2016 10:19:26 +0000 From: Mel Gorman Subject: Re: [RFC PATCH] mm, memcg: fix (Re: OOM: Better, but still there on) Message-ID: <20161230101926.jjjw76negqcvyaim@suse.de> 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=iso-8859-15 Content-Disposition: inline In-Reply-To: <20161226124839.GB20715@dhcp22.suse.cz> Sender: owner-linux-mm@kvack.org List-ID: To: Michal Hocko Cc: Nils Holland , Johannes Weiner , Vladimir Davydov , Tetsuo Handa , linux-kernel@vger.kernel.org, linux-mm@kvack.org, Chris Mason , David Sterba , linux-btrfs@vger.kernel.org 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... > --- > From 397adf46917b2d9493180354a7b0182aee280a8b Mon Sep 17 00:00:00 2001 > From: Michal Hocko > Date: Fri, 23 Dec 2016 15:11:54 +0100 > Subject: [PATCH] mm, memcg: fix the active list aging for lowmem requests when > memcg is enabled > > Nils Holland has reported unexpected OOM killer invocations with 32b > kernel starting with 4.8 kernels > I think it's unfortunate that per-zone stats are reintroduced to the memcg structure. I can't help but think that it would have also worked to always rotate a small number of pages if !inactive_list_is_low and reclaiming for memcg even if it distorted page aging. However, given that such an approach would be less robust and this has been heavily tested; Acked-by: Mel Gorman -- Mel Gorman SUSE Labs -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@kvack.org. For more info on Linux MM, see: http://www.linux-mm.org/ . 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