Messages in this thread | | | Date | Thu, 1 Dec 2016 16:07:15 -0500 | From | Johannes Weiner <> | Subject | Re: [PATCH] mm: workingset: fix NULL ptr in count_shadow_nodes |
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On Thu, Dec 01, 2016 at 02:21:56PM +0100, Michal Hocko wrote: > From: Michal Hocko <mhocko@suse.com> > > 0a6b76dd23fa ("mm: workingset: make shadow node shrinker memcg aware") > has made the workingset shadow nodes shrinker memcg aware. The > implementation is not correct though because memcg_kmem_enabled() might > become true while we are doing a global reclaim when the sc->memcg might > be NULL which is exactly what Marek has seen:
[...]
> This patch fixes the issue by checking sc->memcg rather than memcg_kmem_enabled() > which is sufficient because shrink_slab makes sure that only memcg aware shrinkers > will get non-NULL memcgs and only if memcg_kmem_enabled is true. > > Fixes: 0a6b76dd23fa ("mm: workingset: make shadow node shrinker memcg aware") > Reported-and-tested-by: Marek Marczykowski-Górecki <marmarek@mimuw.edu.pl> > Cc: stable@vger.kernel.org # 4.6+ > Signed-off-by: Michal Hocko <mhocko@suse.com>
Acked-by: Johannes Weiner <hannes@cmpxchg.org>
Thanks Michal
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