On Thu 01-08-19 11:04:14, Masoud Sharbiani wrote: > Hey folks, > I’ve come across an issue that affects most of 4.19, 4.20 and 5.2 linux-stable kernels that has only been fixed in 5.3-rc1. > It was introduced by > > 29ef680 memcg, oom: move out_of_memory back to the charge path This commit shouldn't really change the OOM behavior for your particular test case. It would have changed MAP_POPULATE behavior but your usage is triggering the standard page fault path. The only difference with 29ef680 is that the OOM killer is invoked during the charge path rather than on the way out of the page fault. Anyway, I tried to run your test case in a loop and leaker always ends up being killed as expected with 5.2. See the below oom report. There must be something else going on. How much swap do you have on your system? [337533.314245] leaker invoked oom-killer: gfp_mask=0x100cca(GFP_HIGHUSER_MOVABLE), order=0, oom_score_adj=0 [337533.314250] CPU: 3 PID: 23793 Comm: leaker Not tainted 5.2.0-rc7 #54 [337533.314251] Hardware name: Dell Inc. Latitude E7470/0T6HHJ, BIOS 1.5.3 04/18/2016 [337533.314252] Call Trace: [337533.314258] dump_stack+0x67/0x8e [337533.314262] dump_header+0x51/0x2e9 [337533.314265] ? preempt_count_sub+0xc6/0xd2 [337533.314267] ? _raw_spin_unlock_irqrestore+0x2c/0x3e [337533.314269] oom_kill_process+0x90/0x11d [337533.314271] out_of_memory+0x25c/0x26f [337533.314273] mem_cgroup_out_of_memory+0x8a/0xa6 [337533.314276] try_charge+0x1d0/0x782 [337533.314278] ? preempt_count_sub+0xc6/0xd2 [337533.314280] mem_cgroup_try_charge+0x1a1/0x207 [337533.314282] __add_to_page_cache_locked+0xf9/0x2dd [337533.314285] ? memcg_drain_all_list_lrus+0x125/0x125 [337533.314286] add_to_page_cache_lru+0x3c/0x96 [337533.314288] pagecache_get_page.part.7+0x1d6/0x240 [337533.314290] filemap_fault+0x267/0x54a [337533.314292] ext4_filemap_fault+0x2d/0x41 [337533.314294] ? ext4_page_mkwrite+0x3cd/0x3cd [337533.314296] __do_fault+0x47/0xa7 [337533.314297] __handle_mm_fault+0xaaa/0xf9d [337533.314300] handle_mm_fault+0x174/0x1c3 [337533.314303] __do_page_fault+0x309/0x412 [337533.314305] do_page_fault+0x10b/0x131 [337533.314307] ? page_fault+0x8/0x30 [337533.314309] page_fault+0x1e/0x30 [337533.314311] RIP: 0033:0x55a806ef8503 [337533.314313] Code: 48 89 c6 48 8d 3d 28 0c 00 00 b8 00 00 00 00 e8 73 fb ff ff c7 45 ec 00 00 00 00 eb 36 8b 45 ec 48 63 d0 48 8b 45 c8 48 01 d0 <0f> b6 00 0f be c0 01 45 e4 8b 45 ec 25 ff 0f 00 00 85 c0 75 10 8b [337533.314314] RSP: 002b:00007ffcf6734730 EFLAGS: 00010206 [337533.314316] RAX: 00007f2228f74000 RBX: 0000000000000000 RCX: 0000000000000000 [337533.314317] RDX: 0000000000487000 RSI: 000055a806efc260 RDI: 0000000000000000 [337533.314318] RBP: 00007ffcf6735780 R08: 0000000000000000 R09: 00007ffcf67345fc [337533.314319] R10: 0000000000000000 R11: 0000000000000246 R12: 000055a806ef8120 [337533.314320] R13: 00007ffcf6735860 R14: 0000000000000000 R15: 0000000000000000 [337533.314322] memory: usage 524288kB, limit 524288kB, failcnt 1240247 [337533.314323] memory+swap: usage 2592556kB, limit 9007199254740988kB, failcnt 0 [337533.314324] kmem: usage 7260kB, limit 9007199254740988kB, failcnt 0 [337533.314325] Memory cgroup stats for /leaker: cache:80KB rss:516948KB rss_huge:0KB shmem:0KB mapped_file:0KB dirty:0KB writeback:0KB swap:2068268KB inactive_anon:258520KB active_anon:258412KB inactive_file:32KB active_file:12KB unevictable:0KB [337533.314332] Tasks state (memory values in pages): [337533.314333] [ pid ] uid tgid total_vm rss pgtables_bytes swapents oom_score_adj name [337533.314404] [ 23777] 0 23777 596 400 36864 4 0 sh [337533.314407] [ 23793] 0 23793 655928 126942 5226496 519670 0 leaker [337533.314408] oom-kill:constraint=CONSTRAINT_MEMCG,nodemask=(null),oom_memcg=/leaker,task_memcg=/leaker,task=leaker,pid=23793,uid=0 [337533.314412] Memory cgroup out of memory: Killed process 23793 (leaker) total-vm:2623712kB, anon-rss:506500kB, file-rss:1268kB, shmem-rss:0kB [337533.418036] oom_reaper: reaped process 23793 (leaker), now anon-rss:0kB, file-rss:0kB, shmem-rss:0kB -- Michal Hocko SUSE Labs
