From: Roman Gushchin <guro@xxxxxx> Subject: mm: memcg/slab: don't check the dying flag on kmem_cache creation There is no point in checking the root_cache->memcg_params.dying flag on kmem_cache creation path. New allocations shouldn't be performed using a dead root kmem_cache, so no new memcg kmem_cache creation can be scheduled after the flag is set. And if it was scheduled before, flush_memcg_workqueue() will wait for it anyway. So let's drop this check to simplify the code. Link: http://lkml.kernel.org/r/20190611231813.3148843-7-guro@xxxxxx Signed-off-by: Roman Gushchin <guro@xxxxxx> Acked-by: Vladimir Davydov <vdavydov.dev@xxxxxxxxx> Reviewed-by: Shakeel Butt <shakeelb@xxxxxxxxxx> Cc: Christoph Lameter <cl@xxxxxxxxx> Cc: Johannes Weiner <hannes@xxxxxxxxxxx> Cc: Michal Hocko <mhocko@xxxxxxxx> Cc: Waiman Long <longman@xxxxxxxxxx> Cc: David Rientjes <rientjes@xxxxxxxxxx> Cc: Joonsoo Kim <iamjoonsoo.kim@xxxxxxx> Cc: Pekka Enberg <penberg@xxxxxxxxxx> Cc: Andrei Vagin <avagin@xxxxxxxxx> Cc: Qian Cai <cai@xxxxxx> Signed-off-by: Andrew Morton <akpm@xxxxxxxxxxxxxxxxxxxx> --- mm/slab_common.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) --- a/mm/slab_common.c~mm-dont-check-the-dying-flag-on-kmem_cache-creation +++ a/mm/slab_common.c @@ -640,7 +640,7 @@ void memcg_create_kmem_cache(struct mem_ * The memory cgroup could have been offlined while the cache * creation work was pending. */ - if (memcg->kmem_state != KMEM_ONLINE || root_cache->memcg_params.dying) + if (memcg->kmem_state != KMEM_ONLINE) goto out_unlock; idx = memcg_cache_id(memcg); _
