Re: [PATCH] mm,slab,memcg: call memcg kmem put cache with same condition as get

On Tue, 2019-01-08 at 21:36 -0800, Shakeel Butt wrote:

On Tue, Jan 8, 2019 at 8:01 PM Rik van Riel riel@surriel.com wrote:

...

There is an imbalance between when slab_pre_alloc_hook calls memcg_kmem_get_cache and when slab_post_alloc_hook calls memcg_kmem_put_cache.

Can you explain how there is an imbalance? If the returned kmem cache from memcg_kmem_get_cache() is the memcg kmem cache then the refcnt of memcg is elevated and the memcg_kmem_put_cache() will correctly decrement the refcnt of the memcg.

Indeed, you are right. Never mind this patch.

Back to square one on that bug.