Re: [BUG stable, 2.6.32.27] sched: delayed cleanup of user_struct

Oleg Nesterov
2011-01-10T14:15:47Z

On 01/10, Stefan Priebe - Profihost AG wrote:
>
> Main problem - right i can't reproduce it. But the system was crashing
> two times more in the past.
>
> You can find the logs here:
> http://pastebin.com/hNd15E8K

Good. Sadly, I didn't see this trace before...

kernel BUG at kernel/workqueue.c:287!

this matches "INIT_DELAYED_WORK() can corrupt the pending work" I
mentioned.

>> Or. You can revert
>> b00bc0b237055b4c45816325ee14f0bd83e6f590
>> uids: Prevent tear down race
>>
>> 3959214f971417f4162926ac52ad4cd042958caa
>> sched: delayed cleanup of user_struct
> Not sure if it is a good idea to introduce another race again.

Which race? b00bc0b237055b4c45816325ee14f0bd83e6f590 fixes the race, yes.
But this race was introduced by 3959214f971417f4162926ac52ad4cd042958caa.
And afaics the latter commit is optimization...

Anyway, this is up to you, of course.

Oleg.