diff options
| -rw-r--r-- | include/linux/slab.h | 6 | ||||
| -rw-r--r-- | mm/slab.h | 2 | ||||
| -rw-r--r-- | mm/slab_common.c | 60 | ||||
| -rw-r--r-- | mm/slub.c | 12 |
4 files changed, 76 insertions, 4 deletions
diff --git a/include/linux/slab.h b/include/linux/slab.h index af1a5bef80f4..3c37a8c51921 100644 --- a/include/linux/slab.h +++ b/include/linux/slab.h @@ -582,6 +582,12 @@ struct memcg_cache_params { struct mem_cgroup *memcg; struct list_head children_node; struct list_head kmem_caches_node; + + void (*deact_fn)(struct kmem_cache *); + union { + struct rcu_head deact_rcu_head; + struct work_struct deact_work; + }; }; }; }; diff --git a/mm/slab.h b/mm/slab.h index 7bff1ee513c2..65e7c3fcac72 100644 --- a/mm/slab.h +++ b/mm/slab.h @@ -307,6 +307,8 @@ static __always_inline void memcg_uncharge_slab(struct page *page, int order, extern void slab_init_memcg_params(struct kmem_cache *); extern void memcg_link_cache(struct kmem_cache *s); +extern void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s, + void (*deact_fn)(struct kmem_cache *)); #else /* CONFIG_MEMCG && !CONFIG_SLOB */ diff --git a/mm/slab_common.c b/mm/slab_common.c index 59e41bb81575..c549296c7981 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -627,6 +627,66 @@ out_unlock: put_online_cpus(); } +static void kmemcg_deactivate_workfn(struct work_struct *work) +{ + struct kmem_cache *s = container_of(work, struct kmem_cache, + memcg_params.deact_work); + + get_online_cpus(); + get_online_mems(); + + mutex_lock(&slab_mutex); + + s->memcg_params.deact_fn(s); + + mutex_unlock(&slab_mutex); + + put_online_mems(); + put_online_cpus(); + + /* done, put the ref from slab_deactivate_memcg_cache_rcu_sched() */ + css_put(&s->memcg_params.memcg->css); +} + +static void kmemcg_deactivate_rcufn(struct rcu_head *head) +{ + struct kmem_cache *s = container_of(head, struct kmem_cache, + memcg_params.deact_rcu_head); + + /* + * We need to grab blocking locks. Bounce to ->deact_work. The + * work item shares the space with the RCU head and can't be + * initialized eariler. + */ + INIT_WORK(&s->memcg_params.deact_work, kmemcg_deactivate_workfn); + schedule_work(&s->memcg_params.deact_work); +} + +/** + * slab_deactivate_memcg_cache_rcu_sched - schedule deactivation after a + * sched RCU grace period + * @s: target kmem_cache + * @deact_fn: deactivation function to call + * + * Schedule @deact_fn to be invoked with online cpus, mems and slab_mutex + * held after a sched RCU grace period. The slab is guaranteed to stay + * alive until @deact_fn is finished. This is to be used from + * __kmemcg_cache_deactivate(). + */ +void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s, + void (*deact_fn)(struct kmem_cache *)) +{ + if (WARN_ON_ONCE(is_root_cache(s)) || + WARN_ON_ONCE(s->memcg_params.deact_fn)) + return; + + /* pin memcg so that @s doesn't get destroyed in the middle */ + 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); +} + void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg) { int idx; diff --git a/mm/slub.c b/mm/slub.c index 8a4591526f37..62d0b557a596 100644 --- a/mm/slub.c +++ b/mm/slub.c @@ -3957,6 +3957,12 @@ int __kmem_cache_shrink(struct kmem_cache *s) } #ifdef CONFIG_MEMCG +static void kmemcg_cache_deact_after_rcu(struct kmem_cache *s) +{ + /* called with all the locks held after a sched RCU grace period */ + __kmem_cache_shrink(s); +} + void __kmemcg_cache_deactivate(struct kmem_cache *s) { /* @@ -3968,11 +3974,9 @@ void __kmemcg_cache_deactivate(struct kmem_cache *s) /* * s->cpu_partial is checked locklessly (see put_cpu_partial), so - * we have to make sure the change is visible. + * we have to make sure the change is visible before shrinking. */ - synchronize_sched(); - - __kmem_cache_shrink(s); + slab_deactivate_memcg_cache_rcu_sched(s, kmemcg_cache_deact_after_rcu); } #endif |