On Tue, Jun 04, 2019 at 07:44:45PM -0700, Roman Gushchin wrote: > Johannes noticed that reading the memcg kmem_cache pointer in > cache_from_memcg_idx() is performed using READ_ONCE() macro, > which doesn't implement a SMP barrier, which is required > by the logic. > > Add a proper smp_rmb() to be paired with smp_wmb() in > memcg_create_kmem_cache(). > > The same applies to memcg_create_kmem_cache() itself, > which reads the same value without barriers and READ_ONCE(). > > Suggested-by: Johannes Weiner <hannes@xxxxxxxxxxx> > Signed-off-by: Roman Gushchin <guro@xxxxxx> Acked-by: Johannes Weiner <hannes@xxxxxxxxxxx>
