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

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

>> 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/

Patches marked as 7-* are from Johannes. I'm appling them in order except the grsecurity - it goes as first.

azur




>Btw. the bellow patch might help us to point to the exit path which
>leaves wait_on_memcg without mem_cgroup_oom_synchronize:
>---
>diff --git a/kernel/exit.c b/kernel/exit.c
>index e6e01b9..ad472e0 100644
>--- a/kernel/exit.c
>+++ b/kernel/exit.c
>@@ -895,6 +895,7 @@ NORET_TYPE void do_exit(long code)
> 
> 	profile_task_exit(tsk);
> 
>+	WARN_ON(current->memcg_oom.wait_on_memcg);
> 	WARN_ON(blk_needs_flush_plug(tsk));
> 
> 	if (unlikely(in_interrupt()))
>-- 
>Michal Hocko
>SUSE Labs
>