memory-cgroup bug

From: azurIt
Date: Wed Nov 21 2012 - 14:12:45 EST


Hi,

i'm using memory cgroup for limiting our users and having a really strange problem when a cgroup gets out of its memory limit. It's very strange because it happens only sometimes (about once per week on random user), out of memory is usually handled ok. This happens when problem occures:
- no new processes can be started for this cgroup
- current processes are freezed and taking 100% of CPU
- when i try to 'strace' any of current processes, the whole strace freezes until process is killed (strace cannot be terminated by CTRL-c)
- problem can be resolved by raising memory limit for cgroup or killing of few processes inside cgroup so some memory is freed

I also garbbed the content of /proc/<pid>/stack of freezed process:
[<ffffffff8110a9c1>] mem_cgroup_handle_oom+0x241/0x3b0
[<ffffffff8110b5ab>] T.1146+0x5ab/0x5c0
[<ffffffff8110ba56>] mem_cgroup_charge_common+0x56/0xa0
[<ffffffff8110bae5>] mem_cgroup_newpage_charge+0x45/0x50
[<ffffffff810ec54e>] do_wp_page+0x14e/0x800
[<ffffffff810eda34>] handle_pte_fault+0x264/0x940
[<ffffffff810ee248>] handle_mm_fault+0x138/0x260
[<ffffffff810270ed>] do_page_fault+0x13d/0x460
[<ffffffff815b53ff>] page_fault+0x1f/0x30
[<ffffffffffffffff>] 0xffffffffffffffff

I'm currently using kernel 3.2.34 but i'm having this problem since 2.6.32.

Any ideas? Thnx.

azurIt
--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@xxxxxxxxxxxxxxx
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/