>stuck in the ptrace code. But this happens _after_ the cgroup was freezed and i tried to strace one of it's processes (to see what's happening): Feb 8 01:29:46 server01 kernel: [ 1187.540672] grsec: From 178.40.250.111: process /usr/lib/apache2/mpm-itk/apache2(apache2:18211) attached to via ptrace by /usr/bin/strace[strace:18258] uid/euid:0/0 gid/egid:0/0, parent /usr/bin/htop[htop:2901] uid/euid:0/0 gid/egid:0/0 >> Why are all PIDs waiting on 'mem_cgroup_handle_oom' and there is no >> OOM message in the log? > >I am not sure what you mean here but there are >$ grep "Memory cgroup out of memory:" kern2.collected.log | wc -l >16 > >OOM killer events during the time you were gathering memcg-bug-4 data. > >> Data in memcg-bug-4.tar.gz are only for 2 >> minutes but i let it run for about 15-20 minutes, no single process >> killed by OOM. > >I can see >$ grep "Memory cgroup out of memory:" kern2.after.log | wc -l >57 > >killed after 02:38:47 when you stopped gathering data for memcg-bug-4 I meant no single process was killed inside cgroup 1258 (data from this cgroup are in memcg-bug-4.tar.gz). Just get data from memcg-bug-4.tar.gz which were taken from cgroup 1258. Almost all processes are in 'mem_cgroup_handle_oom' so cgroup is under OOM. I assume that this is suppose to take only few seconds while kernel finds any process and kill it (and maybe do it again until enough of memory is freed). I was gathering the data for about 2 and a half minutes and NO SINGLE process was killed (just compate list of PIDs from the first and the last directory inside memcg-bug-4.tar.gz). Even more, no single process was killed in cgroup 1258 also after i stopped gathering the data. You can also take the list od PID from memcg-bug-4.tar.gz and you will find only 18211 and 8102 (which are the two stucked processes). So my question is: Why no process was killed inside cgroup 1258 while it was under OOM? It was under OOM for at least 2 and a half of minutes while i was gathering the data (then i let it run for additional, cca, 10 minutes and then killed processes by hand but i cannot proof this). Why kernel didn't kill any process for so long and ends the OOM? Btw, processes in cgroup 1258 (memcg-bug-4.tar.gz) are looping in this two tasks (i pasted only first line of stack): mem_cgroup_handle_oom+0x241/0x3b0 0xffffffffffffffff Some of them are in 'poll_schedule_timeout' and then they start to loop as above. Is this correct behavior? For example, do (first line of stack from process 7710 from all timestamps): for i in */7710/stack; do head -n1 $i; done -- 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>