Messages in this thread | | | Date | Mon, 29 Jul 2019 09:18:01 +0100 | From | Qais Yousef <> | Subject | Re: [PATCH v2] sched/core: Don't use dying mm as active_mm of kthreads |
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On 07/27/19 13:10, Waiman Long wrote: > It was found that a dying mm_struct where the owning task has exited > can stay on as active_mm of kernel threads as long as no other user > tasks run on those CPUs that use it as active_mm. This prolongs the > life time of dying mm holding up memory and other resources like swap > space that cannot be freed. > > Fix that by forcing the kernel threads to use init_mm as the active_mm > if the previous active_mm is dying. > > The determination of a dying mm is based on the absence of an owning > task. The selection of the owning task only happens with the CONFIG_MEMCG > option. Without that, there is no simple way to determine the life span > of a given mm. So it falls back to the old behavior.
I don't really know a lot about this code, but does the owner field has to depend on CONFIG_MEMCG? ie: can't the owner be always set?
Cheers
-- Qais Yousef
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