From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S934959AbaFTQgT (ORCPT ); Fri, 20 Jun 2014 12:36:19 -0400 Received: from cantor2.suse.de ([195.135.220.15]:59723 "EHLO mx2.suse.de" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932908AbaFTQgS (ORCPT ); Fri, 20 Jun 2014 12:36:18 -0400 From: Michal Hocko To: Andrew Morton , Johannes Weiner Cc: Hugh Dickins , Tejun Heo , Vladimir Davydov , , LKML Subject: [PATCH -mm] memcg: mem_cgroup_charge_statistics needs preempt_disable Date: Fri, 20 Jun 2014 18:36:11 +0200 Message-Id: <1403282171-25502-1-git-send-email-mhocko@suse.cz> X-Mailer: git-send-email 2.0.0 In-Reply-To: <1403124045-24361-14-git-send-email-hannes@cmpxchg.org> References: <1403124045-24361-14-git-send-email-hannes@cmpxchg.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org preempt_disable was previously disabled by lock_page_cgroup which has been removed by "mm: memcontrol: rewrite uncharge API". This fixes the a flood of splats like this: [ 3.149371] BUG: using __this_cpu_add() in preemptible [00000000] code: udevd/1271 [ 3.151458] caller is __this_cpu_preempt_check+0x13/0x15 [ 3.152927] CPU: 0 PID: 1271 Comm: udevd Not tainted 3.15.0-test1 #366 [ 3.154637] Hardware name: QEMU Standard PC (i440FX + PIIX, 1996), BIOS Bochs 01/01/2011 [ 3.156788] 0000000000000000 ffff88000005fba8 ffffffff814efe3f 0000000000000000 [ 3.158810] ffff88000005fbd8 ffffffff8125b969 ffff880007413448 0000000000000001 [ 3.160836] ffffea00001e8c00 0000000000000001 ffff88000005fbe8 ffffffff8125b9a8 [ 3.162950] Call Trace: [ 3.163598] [] dump_stack+0x4e/0x7a [ 3.164942] [] check_preemption_disabled+0xd2/0xe5 [ 3.166618] [] __this_cpu_preempt_check+0x13/0x15 [ 3.168267] [] mem_cgroup_charge_statistics.isra.36+0xb5/0xc6 [ 3.170169] [] commit_charge+0x23c/0x256 [ 3.171823] [] mem_cgroup_commit_charge+0xb8/0xd7 [ 3.173838] [] shmem_getpage_gfp+0x399/0x605 [ 3.175363] [] shmem_write_begin+0x3d/0x58 [ 3.176854] [] generic_perform_write+0xbc/0x192 [ 3.178445] [] ? file_update_time+0x34/0xac [ 3.179952] [] __generic_file_aio_write+0x2c0/0x300 [ 3.181655] [] generic_file_aio_write+0x52/0xbd [ 3.183234] [] do_sync_write+0x59/0x78 [ 3.184630] [] vfs_write+0xc4/0x181 [ 3.185957] [] SyS_write+0x4a/0x91 [ 3.187258] [] tracesys+0xd0/0xd5 Signed-off-by: Michal Hocko --- Andrew, the changelog is quite modest but this should be folded into mm-memcontrol-rewrite-uncharge-api.patch anyway. If you want a regular patch, please let me know. mm/memcontrol.c | 3 +++ 1 file changed, 3 insertions(+) diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 241cf4f91e24..cbf373085b6c 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -904,6 +904,8 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, struct page *page, int nr_pages) { + preempt_disable(); + /* * Here, RSS means 'mapped anon' and anon's SwapCache. Shmem/tmpfs is * counted as CACHE even if it's on ANON LRU. @@ -928,6 +930,7 @@ static void mem_cgroup_charge_statistics(struct mem_cgroup *memcg, } __this_cpu_add(memcg->stat->nr_page_events, nr_pages); + preempt_enable(); } unsigned long mem_cgroup_get_lru_size(struct lruvec *lruvec, enum lru_list lru) -- 2.0.0