Re: process hangs on do_exit when oom happens

From: Balbir Singh
Date: Tue Oct 23 2012 - 13:43:48 EST


On Tue, Oct 23, 2012 at 3:45 PM, Michal Hocko <mhocko@xxxxxxx> wrote:
> On Tue 23-10-12 18:10:33, Qiang Gao wrote:
>> On Tue, Oct 23, 2012 at 5:50 PM, Michal Hocko <mhocko@xxxxxxx> wrote:
>> > On Tue 23-10-12 15:18:48, Qiang Gao wrote:
>> >> This process was moved to RT-priority queue when global oom-killer
>> >> happened to boost the recovery of the system..
>> >
>> > Who did that? oom killer doesn't boost the priority (scheduling class)
>> > AFAIK.
>> >
>> >> but it wasn't get properily dealt with. I still have no idea why where
>> >> the problem is ..
>> >
>> > Well your configuration says that there is no runtime reserved for the
>> > group.
>> > Please refer to Documentation/scheduler/sched-rt-group.txt for more
>> > information.
>> >
> [...]
>> maybe this is not a upstream-kernel bug. the centos/redhat kernel
>> would boost the process to RT prio when the process was selected
>> by oom-killer.
>
> This still looks like your cpu controller is misconfigured. Even if the
> task is promoted to be realtime.


Precisely! You need to have rt bandwidth enabled for RT tasks to run,
as a workaround please give the groups some RT bandwidth and then work
out the migration to RT and what should be the defaults on the distro.

Balbir
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