diff --git a/include/linux/slab.h b/include/linux/slab.h index 4d759e1ddc33..14e3fe4bd6a1 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -600,6 +600,7 @@ struct memcg_cache_params { struct memcg_cache_array __rcu *memcg_caches; struct list_head __root_caches_node; struct list_head children; + bool dying; }; struct { struct mem_cgroup *memcg; diff --git a/mm/slab_common.c b/mm/slab_common.c index 98dcdc352062..42aca26d61d0 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -136,6 +136,7 @@ void slab_init_memcg_params(struct kmem_cache *s) s->memcg_params.root_cache = NULL; RCU_INIT_POINTER(s->memcg_params.memcg_caches, NULL); INIT_LIST_HEAD(&s->memcg_params.children); + s->memcg_params.dying = false; } static int init_memcg_params(struct kmem_cache *s, @@ -608,7 +609,7 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg, * The memory cgroup could have been offlined while the cache * creation work was pending. */ - if (memcg->kmem_state != KMEM_ONLINE) + if (memcg->kmem_state != KMEM_ONLINE || root_cache->memcg_params.dying) goto out_unlock; idx = memcg_cache_id(memcg); @@ -712,6 +713,9 @@ void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s, WARN_ON_ONCE(s->memcg_params.deact_fn)) return; + if (s->memcg_params.root_cache->memcg_params.dying) + return; + /* pin memcg so that @s doesn't get destroyed in the middle */ css_get(&s->memcg_params.memcg->css); @@ -823,11 +827,36 @@ static int shutdown_memcg_caches(struct kmem_cache *s) return -EBUSY; return 0; } + +static void flush_memcg_workqueue(struct kmem_cache *s) +{ + mutex_lock(&slab_mutex); + s->memcg_params.dying = true; + mutex_unlock(&slab_mutex); + + /* + * SLUB deactivates the kmem_caches through call_rcu_sched. Make + * sure all registered rcu callbacks have been invoked. + */ + if (IS_ENABLED(CONFIG_SLUB)) + rcu_barrier_sched(); + + /* + * SLAB and SLUB create memcg kmem_caches through workqueue and SLUB + * deactivates the memcg kmem_caches through workqueue. Make sure all + * previous workitems on workqueue are processed. + */ + flush_workqueue(memcg_kmem_cache_wq); +} #else static inline int shutdown_memcg_caches(struct kmem_cache *s) { return 0; } + +static inline void flush_memcg_workqueue(struct kmem_cache *s) +{ +} #endif /* CONFIG_MEMCG && !CONFIG_SLOB */ void slab_kmem_cache_release(struct kmem_cache *s) @@ -845,6 +874,8 @@ void kmem_cache_destroy(struct kmem_cache *s) if (unlikely(!s)) return; + flush_memcg_workqueue(s); + get_online_cpus(); get_online_mems();