From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1759300AbcLWW0K (ORCPT ); Fri, 23 Dec 2016 17:26:10 -0500 Received: from celine.tisys.org ([85.25.117.166]:54878 "EHLO celine.tisys.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753705AbcLWW0I (ORCPT ); Fri, 23 Dec 2016 17:26:08 -0500 Date: Fri, 23 Dec 2016 23:26:00 +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: <20161223222559.GA5568@teela.multi.box> References: <20161219134534.GC5164@dhcp22.suse.cz> <20161220020829.GA5449@boerne.fritz.box> <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> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20161223144738.GB23117@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 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 [ 1.568754] Modules linked in: [ 1.568922] CPU: 0 PID: 1 Comm: swapper/0 Not tainted 4.9.0-gentoo #6 [ 1.569052] Hardware name: Hewlett-Packard Compaq 15 Notebook PC/21F7, BIOS F.22 08/06/2014 [ 1.571750] f44e5b84 c142bdee f44e5bc8 c1b5ade0 f44e5bb4 c103ab1d c1b583e4 f44e5be4 [ 1.572262] 00000001 c1b5ade0 00000408 c11603d8 00000408 00000000 c1b5af73 00000001 [ 1.572774] f44e5bd0 c103ab76 00000009 00000000 f44e5bc8 c1b583e4 f44e5be4 f44e5c18 [ 1.573285] Call Trace: [ 1.573419] [] dump_stack+0x47/0x69 [ 1.573551] [] __warn+0xed/0x110 [ 1.573681] [] ? mem_cgroup_update_lru_size+0x118/0x130 [ 1.573812] [] warn_slowpath_fmt+0x36/0x40 [ 1.573942] [] mem_cgroup_update_lru_size+0x118/0x130 [ 1.574076] [] __pagevec_lru_add_fn+0xd7/0x1b0 [ 1.574206] [] ? perf_trace_mm_lru_insertion+0x150/0x150 [ 1.574336] [] pagevec_lru_move_fn+0x4d/0x80 [ 1.574465] [] ? perf_trace_mm_lru_insertion+0x150/0x150 [ 1.574595] [] __lru_cache_add+0x45/0x60 [ 1.574724] [] lru_cache_add+0x8/0x10 [ 1.574852] [] add_to_page_cache_lru+0x61/0xc0 [ 1.574982] [] pagecache_get_page+0xee/0x270 [ 1.575111] [] grab_cache_page_write_begin+0x20/0x40 [ 1.575243] [] simple_write_begin+0x25/0xd0 [ 1.575372] [] generic_perform_write+0xa8/0x1a0 [ 1.575503] [] __generic_file_write_iter+0x197/0x1f0 [ 1.575634] [] generic_file_write_iter+0x19f/0x2b0 [ 1.575766] [] __vfs_write+0xd1/0x140 [ 1.575897] [] vfs_write+0x95/0x1b0 [ 1.576026] [] SyS_write+0x3f/0x90 [ 1.576157] [] xwrite+0x1c/0x4b [ 1.576285] [] do_copy+0x22/0xac [ 1.576413] [] write_buffer+0x1d/0x2c [ 1.576540] [] flush_buffer+0x1e/0x70 [ 1.576670] [] unxz+0x149/0x211 [ 1.576798] [] ? unlzo+0x359/0x359 [ 1.576926] [] unpack_to_rootfs+0x14f/0x246 [ 1.577054] [] ? write_buffer+0x2c/0x2c [ 1.577183] [] ? initrd_load+0x3b/0x3b [ 1.577312] [] ? maybe_link.part.3+0xe3/0xe3 [ 1.577443] [] populate_rootfs+0x47/0x8f [ 1.577573] [] do_one_initcall+0x36/0x150 [ 1.577701] [] ? repair_env_string+0x12/0x54 [ 1.577832] [] ? parse_args+0x25d/0x400 [ 1.577962] [] ? kernel_init_freeable+0x101/0x19e [ 1.578092] [] kernel_init_freeable+0x121/0x19e [ 1.578222] [] ? rest_init+0x60/0x60 [ 1.578350] [] kernel_init+0xb/0x100 [ 1.578480] [] ? schedule_tail+0xc/0x50 [ 1.578608] [] ? rest_init+0x60/0x60 [ 1.578737] [] ret_from_fork+0x1b/0x28 [ 1.578871] ---[ end trace cf6f1adac9dfe60e ]--- The machine then continued to boot just normally, however, so I started my ordinary tests. And in fact, they were working just fine, i.e. no OOMing anymore, even during heavy tarball unpacking. Would it make sense to capture more trace data for you at this point? As I'm on the go, I don't currently have a second machine for capturing over the network, but since we're not having OOMs or other issues now, capturing to file should probably work just fine. I'll keep the patch applied and see if I notice anything else that doesn't look normal during day to day usage, especially during my ordinary Gentoo updates, which consist of a lot of fetching / unpacking / building, and in the recent past had been very problematic (in fact, that was where the problem first struck me and the "heavy tarball unpacking" test was then just what I distilled it down to in order to manually reproduce this with the least time and effort possible). Greetings Nils