Re: [PATCH 2/5] oom reaper: handle mlocked pages

From: David Rientjes
Date: Wed Feb 03 2016 - 18:58:00 EST


On Wed, 3 Feb 2016, Michal Hocko wrote:

> From: Michal Hocko <mhocko@xxxxxxxx>
>
> __oom_reap_vmas current skips over all mlocked vmas because they need a
> special treatment before they are unmapped. This is primarily done for
> simplicity. There is no reason to skip over them and reduce the amount
> of reclaimed memory. This is safe from the semantic point of view
> because try_to_unmap_one during rmap walk would keep tell the reclaim
> to cull the page back and mlock it again.
>
> munlock_vma_pages_all is also safe to be called from the oom reaper
> context because it doesn't sit on any locks but mmap_sem (for read).
>
> Signed-off-by: Michal Hocko <mhocko@xxxxxxxx>

Acked-by: David Rientjes <rientjes@xxxxxxxxxx>