Re: [PATCH 2/9] slab: remove synchronous rcu_barrier() call in memcg cache release path

Tejun Heo
2017-01-17T17:02:15Z

On Tue, Jan 17, 2017 at 08:37:45AM -0800, Tejun Heo wrote:
> The call sequence doesn't matter. Whether you're using call_rcu() or
> rcu_barrier(), you're just waiting for a grace period to pass before
> continuing. It doens't give any other ordering guarantees, so the new
> code should be equivalent to the old one except for being asynchronous.

Oh I was confusing synchronize_rcu() with rcu_barrier(), so you're
right, kmem_cache struct needs to stay around for the slab pages to be
freed after RCU grace period. Will revise the patch accordingly,
thanks.

Thanks.

--
tejun