Re: Lockup in wait_transaction_locked under memory pressure

[Nikolay Borisov <kernel@kyup.com>]

On 06/29/2015 11:32 AM, Michal Hocko wrote:
> On Thu 25-06-15 18:27:10, Nikolay Borisov wrote:
>>
>>
>> On 06/25/2015 06:18 PM, Michal Hocko wrote:
>>> On Thu 25-06-15 17:34:22, Nikolay Borisov wrote:
>>>> On 06/25/2015 05:05 PM, Michal Hocko wrote:
>>>>> On Thu 25-06-15 16:49:43, Nikolay Borisov wrote:
>>>>> [...]
>>>>>> How would you advise to rectify such situation?
>>>>>
>>>>> As I've said. Check the oom victim traces and see if it is holding any
>>>>> of those locks.
>>>>
>>>> As mentioned previously all OOM traces are identical to the one I've
>>>> sent - OOM being called form the page fault path.
>>>  
>>> By identical you mean that all of them kill the same task? Or just that
>>> the path is same (which wouldn't be surprising as this is the only path
>>> which triggers memcg oom killer)?
>>
>> The code path is the same, the tasks being killed are different
> 
> Is the OOM killer triggered only for a singe memcg or others misbehave
> as well?

Generally OOM would be triggered for whichever memcg runs out of
resources but so far I've only observed that the D state issue happens
in a single containers. However, this in turn might affect other
processes if they try to sleep on the same jbd2 journal .