Commit 6564a25e authored by Paul E. McKenney's avatar Paul E. McKenney
Browse files

slab: Replace synchronize_sched() with synchronize_rcu() 



Now that synchronize_rcu() waits for preempt-disable regions of code
as well as RCU read-side critical sections, synchronize_sched() can be
replaced by synchronize_rcu().  This commit therefore makes this change.

Signed-off-by: default avatarPaul E. McKenney <paulmck@linux.ibm.com>
Cc: Christoph Lameter <cl@linux.com>
Cc: Pekka Enberg <penberg@kernel.org>
Cc: David Rientjes <rientjes@google.com>
Cc: Joonsoo Kim <iamjoonsoo.kim@lge.com>
Cc: Andrew Morton <akpm@linux-foundation.org>
Cc: <linux-mm@kvack.org>
parent 36bd1a8e

mm/slab.c

+2 −2
Original line number Diff line number Diff line
@@ -962,10 +962,10 @@ static int setup_kmem_cache_node(struct kmem_cache *cachep, 
	 * To protect lockless access to n->shared during irq disabled context.

	 * If n->shared isn't NULL in irq disabled context, accessing to it is

	 * guaranteed to be valid until irq is re-enabled, because it will be

	 * freed after synchronize_sched().

	 * freed after synchronize_rcu().

	 */

	if (old_shared && force_change)

		synchronize_sched();

		synchronize_rcu();



fail:

	kfree(old_shared);

mm/slab_common.c

+3 −3
Original line number Diff line number Diff line
@@ -724,7 +724,7 @@ void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s, 
	css_get(&s->memcg_params.memcg->css);



	s->memcg_params.deact_fn = deact_fn;

	call_rcu_sched(&s->memcg_params.deact_rcu_head, kmemcg_deactivate_rcufn);

	call_rcu(&s->memcg_params.deact_rcu_head, kmemcg_deactivate_rcufn);

}



void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg)
@@ -839,11 +839,11 @@ static void flush_memcg_workqueue(struct kmem_cache *s) 
	mutex_unlock(&slab_mutex);



	/*

	 * SLUB deactivates the kmem_caches through call_rcu_sched. Make

	 * SLUB deactivates the kmem_caches through call_rcu. Make

	 * sure all registered rcu callbacks have been invoked.

	 */

	if (IS_ENABLED(CONFIG_SLUB))

		rcu_barrier_sched();

		rcu_barrier();



	/*

	 * SLAB and SLUB create memcg kmem_caches through workqueue and SLUB

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