Re: [PATCH for 3.2] memcg: do not trap chargers with full callstack on OOM

["azurIt" <azurit@pobox.sk>]

> CC: "Johannes Weiner" <hannes@cmpxchg.org>, linux-kernel@vger.kernel.org, linux-mm@kvack.org, "cgroups mailinglist" <cgroups@vger.kernel.org>, "KAMEZAWA Hiroyuki" <kamezawa.hiroyu@jp.fujitsu.com>, righi.andrea@gmail.com
>> CC: "Johannes Weiner" <hannes@cmpxchg.org>, linux-kernel@vger.kernel.org, linux-mm@kvack.org, "cgroups mailinglist" <cgroups@vger.kernel.org>, "KAMEZAWA Hiroyuki" <kamezawa.hiroyu@jp.fujitsu.com>, righi.andrea@gmail.com
>>On Wed 10-07-13 18:25:06, azurIt wrote:
>>> >> Now i realized that i forgot to remove UID from that cgroup before
>>> >> trying to remove it, so cgroup cannot be removed anyway (we are using
>>> >> third party cgroup called cgroup-uid from Andrea Righi, which is able
>>> >> to associate all user's processes with target cgroup). Look here for
>>> >> cgroup-uid patch:
>>> >> https://www.develer.com/~arighi/linux/patches/cgroup-uid/cgroup-uid-v8.patch
>>> >> 
>>> >> ANYWAY, i'm 101% sure that 'tasks' file was empty and 'under_oom' was
>>> >> permanently '1'.
>>> >
>>> >This is really strange. Could you post the whole diff against stable
>>> >tree you are using (except for grsecurity stuff and the above cgroup-uid
>>> >patch)?
>>> 
>>> 
>>> Here are all patches which i applied to kernel 3.2.48 in my last test:
>>> http://watchdog.sk/lkml/patches3/
>>
>>The two patches from Johannes seem correct.
>>
>>From a quick look even grsecurity patchset shouldn't interfere as it
>>doesn't seem to put any code between handle_mm_fault and mm_fault_error
>>and there also doesn't seem to be any new handle_mm_fault call sites.
>>
>>But I cannot tell there aren't other code paths which would lead to a
>>memcg charge, thus oom, without proper FAULT_FLAG_KERNEL handling.
>
>
>Michal,
>
>now i can definitely confirm that problem with unremovable cgroups persists. What info do you need from me? I applied also your little 'WARN_ON' patch.
>
>azur



Ok, i think you want this:
http://watchdog.sk/lkml/kern4.log

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