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SubjectRe: [PATCH v6 01/10] mm: add missing smp read barrier on getting memcg kmem_cache pointer
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@cmpxchg.org>
> Signed-off-by: Roman Gushchin <guro@fb.com>

Acked-by: Johannes Weiner <hannes@cmpxchg.org>

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