Re: OOM: Better, but still there on

[Chris Mason]

On Wed, Dec 21, 2016 at 12:16:53PM +0100, Michal Hocko wrote:
> On Wed 21-12-16 20:00:38, Tetsuo Handa wrote:
>
> One thing to note here, when we are talking about 32b kernel, things
> have changed in 4.8 when we moved from the zone based to node based
> reclaim (see b2e18757f2c9 ("mm, vmscan: begin reclaiming pages on a
> per-node basis") and associated patches). It is possible that the
> reporter is hitting some pathological path which needs fixing but it
> might be also related to something else. So I am rather not trying to
> blame 32b yet...

It might be interesting to put tracing on releasepage and see if btrfs 
is pinning pages around.  I can't see how 32bit kernels would be 
different, but maybe we're hitting a weird corner.

-chris