diff options
Diffstat (limited to 'mm/slab_common.c')
| -rw-r--r-- | mm/slab_common.c | 67 |
1 files changed, 55 insertions, 12 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c index cbd3411f644e..70fb7eec7360 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -130,6 +130,7 @@ int __kmem_cache_alloc_bulk(struct kmem_cache *s, gfp_t flags, size_t nr, #ifdef CONFIG_MEMCG_KMEM LIST_HEAD(slab_root_caches); +static DEFINE_SPINLOCK(memcg_kmem_wq_lock); void slab_init_memcg_params(struct kmem_cache *s) { @@ -310,6 +311,14 @@ int slab_unmergeable(struct kmem_cache *s) if (s->refcount < 0) return 1; +#ifdef CONFIG_MEMCG_KMEM + /* + * Skip the dying kmem_cache. + */ + if (s->memcg_params.dying) + return 1; +#endif + return 0; } @@ -744,14 +753,22 @@ void slab_deactivate_memcg_cache_rcu_sched(struct kmem_cache *s, WARN_ON_ONCE(s->memcg_params.deact_fn)) return; + /* + * memcg_kmem_wq_lock is used to synchronize memcg_params.dying + * flag and make sure that no new kmem_cache deactivation tasks + * are queued (see flush_memcg_workqueue() ). + */ + spin_lock_irq(&memcg_kmem_wq_lock); if (s->memcg_params.root_cache->memcg_params.dying) - return; + goto unlock; /* 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(&s->memcg_params.deact_rcu_head, kmemcg_deactivate_rcufn); +unlock: + spin_unlock_irq(&memcg_kmem_wq_lock); } void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg) @@ -859,12 +876,15 @@ static int shutdown_memcg_caches(struct kmem_cache *s) return 0; } -static void flush_memcg_workqueue(struct kmem_cache *s) +static void memcg_set_kmem_cache_dying(struct kmem_cache *s) { - mutex_lock(&slab_mutex); + spin_lock_irq(&memcg_kmem_wq_lock); s->memcg_params.dying = true; - mutex_unlock(&slab_mutex); + spin_unlock_irq(&memcg_kmem_wq_lock); +} +static void flush_memcg_workqueue(struct kmem_cache *s) +{ /* * SLUB deactivates the kmem_caches through call_rcu. Make * sure all registered rcu callbacks have been invoked. @@ -877,17 +897,26 @@ static void flush_memcg_workqueue(struct kmem_cache *s) * deactivates the memcg kmem_caches through workqueue. Make sure all * previous workitems on workqueue are processed. */ - flush_workqueue(memcg_kmem_cache_wq); + if (likely(memcg_kmem_cache_wq)) + flush_workqueue(memcg_kmem_cache_wq); + + /* + * If we're racing with children kmem_cache deactivation, it might + * take another rcu grace period to complete their destruction. + * At this moment the corresponding percpu_ref_kill() call should be + * done, but it might take another rcu grace period to complete + * switching to the atomic mode. + * Please, note that we check without grabbing the slab_mutex. It's safe + * because at this moment the children list can't grow. + */ + if (!list_empty(&s->memcg_params.children)) + rcu_barrier(); } #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_KMEM */ void slab_kmem_cache_release(struct kmem_cache *s) @@ -905,8 +934,6 @@ void kmem_cache_destroy(struct kmem_cache *s) if (unlikely(!s)) return; - flush_memcg_workqueue(s); - get_online_cpus(); get_online_mems(); @@ -916,6 +943,22 @@ void kmem_cache_destroy(struct kmem_cache *s) if (s->refcount) goto out_unlock; +#ifdef CONFIG_MEMCG_KMEM + memcg_set_kmem_cache_dying(s); + + mutex_unlock(&slab_mutex); + + put_online_mems(); + put_online_cpus(); + + flush_memcg_workqueue(s); + + get_online_cpus(); + get_online_mems(); + + mutex_lock(&slab_mutex); +#endif + err = shutdown_memcg_caches(s); if (!err) err = shutdown_cache(s); @@ -1593,7 +1636,7 @@ void kzfree(const void *p) if (unlikely(ZERO_OR_NULL_PTR(mem))) return; ks = ksize(mem); - memset(mem, 0, ks); + memzero_explicit(mem, ks); kfree(mem); } EXPORT_SYMBOL(kzfree); |