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] [<ffffffff814efe3f>] dump_stack+0x4e/0x7a [ 3.164942] [<ffffffff8125b969>] check_preemption_disabled+0xd2/0xe5 [ 3.166618] [<ffffffff8125b9a8>] __this_cpu_preempt_check+0x13/0x15 [ 3.168267] [<ffffffff8112b630>] mem_cgroup_charge_statistics.isra.36+0xb5/0xc6 [ 3.170169] [<ffffffff8112d2c5>] commit_charge+0x23c/0x256 [ 3.171823] [<ffffffff8113101b>] mem_cgroup_commit_charge+0xb8/0xd7 [ 3.173838] [<ffffffff810f5dab>] shmem_getpage_gfp+0x399/0x605 [ 3.175363] [<ffffffff810f7456>] shmem_write_begin+0x3d/0x58 [ 3.176854] [<ffffffff810e1361>] generic_perform_write+0xbc/0x192 [ 3.178445] [<ffffffff8114a086>] ? file_update_time+0x34/0xac [ 3.179952] [<ffffffff810e2ae4>] __generic_file_aio_write+0x2c0/0x300 [ 3.181655] [<ffffffff810e2b76>] generic_file_aio_write+0x52/0xbd [ 3.183234] [<ffffffff81133944>] do_sync_write+0x59/0x78 [ 3.184630] [<ffffffff81133ea8>] vfs_write+0xc4/0x181 [ 3.185957] [<ffffffff81134801>] SyS_write+0x4a/0x91 [ 3.187258] [<ffffffff814fd30e>] tracesys+0xd0/0xd5 Signed-off-by: Michal Hocko <mhocko@xxxxxxx> --- 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 -- To unsubscribe, send a message with 'unsubscribe linux-mm' in the body to majordomo@xxxxxxxxx. For more info on Linux MM, see: http://www.linux-mm.org/ . Don't email: <a href=mailto:"dont@xxxxxxxxx"> email@xxxxxxxxx </a>