diff options
Diffstat (limited to 'mm/slab_common.c')
-rw-r--r-- | mm/slab_common.c | 142 |
1 files changed, 102 insertions, 40 deletions
diff --git a/mm/slab_common.c b/mm/slab_common.c index 5ce4fae..d88e97c 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -316,10 +316,10 @@ unsigned long calculate_alignment(unsigned long flags, return ALIGN(align, sizeof(void *)); } -static struct kmem_cache * -do_kmem_cache_create(const char *name, size_t object_size, size_t size, - size_t align, unsigned long flags, void (*ctor)(void *), - struct mem_cgroup *memcg, struct kmem_cache *root_cache) +static struct kmem_cache *create_cache(const char *name, + size_t object_size, size_t size, size_t align, + unsigned long flags, void (*ctor)(void *), + struct mem_cgroup *memcg, struct kmem_cache *root_cache) { struct kmem_cache *s; int err; @@ -384,7 +384,7 @@ struct kmem_cache * kmem_cache_create(const char *name, size_t size, size_t align, unsigned long flags, void (*ctor)(void *)) { - struct kmem_cache *s; + struct kmem_cache *s = NULL; const char *cache_name; int err; @@ -396,7 +396,6 @@ kmem_cache_create(const char *name, size_t size, size_t align, err = kmem_cache_sanity_check(name, size); if (err) { - s = NULL; /* suppress uninit var warning */ goto out_unlock; } @@ -418,9 +417,9 @@ kmem_cache_create(const char *name, size_t size, size_t align, goto out_unlock; } - s = do_kmem_cache_create(cache_name, size, size, - calculate_alignment(flags, align, size), - flags, ctor, NULL, NULL); + s = create_cache(cache_name, size, size, + calculate_alignment(flags, align, size), + flags, ctor, NULL, NULL); if (IS_ERR(s)) { err = PTR_ERR(s); kfree_const(cache_name); @@ -448,29 +447,20 @@ out_unlock: } EXPORT_SYMBOL(kmem_cache_create); -static int do_kmem_cache_shutdown(struct kmem_cache *s, +static int shutdown_cache(struct kmem_cache *s, struct list_head *release, bool *need_rcu_barrier) { - if (__kmem_cache_shutdown(s) != 0) { - printk(KERN_ERR "kmem_cache_destroy %s: " - "Slab cache still has objects\n", s->name); - dump_stack(); + if (__kmem_cache_shutdown(s) != 0) return -EBUSY; - } if (s->flags & SLAB_DESTROY_BY_RCU) *need_rcu_barrier = true; -#ifdef CONFIG_MEMCG_KMEM - if (!is_root_cache(s)) - list_del(&s->memcg_params.list); -#endif list_move(&s->list, release); return 0; } -static void do_kmem_cache_release(struct list_head *release, - bool need_rcu_barrier) +static void release_caches(struct list_head *release, bool need_rcu_barrier) { struct kmem_cache *s, *s2; @@ -536,10 +526,10 @@ void memcg_create_kmem_cache(struct mem_cgroup *memcg, if (!cache_name) goto out_unlock; - s = do_kmem_cache_create(cache_name, root_cache->object_size, - root_cache->size, root_cache->align, - root_cache->flags, root_cache->ctor, - memcg, root_cache); + s = create_cache(cache_name, root_cache->object_size, + root_cache->size, root_cache->align, + root_cache->flags, root_cache->ctor, + memcg, root_cache); /* * If we could not create a memcg cache, do not complain, because * that's not critical at all as we can always proceed with the root @@ -598,6 +588,18 @@ void memcg_deactivate_kmem_caches(struct mem_cgroup *memcg) put_online_cpus(); } +static int __shutdown_memcg_cache(struct kmem_cache *s, + struct list_head *release, bool *need_rcu_barrier) +{ + BUG_ON(is_root_cache(s)); + + if (shutdown_cache(s, release, need_rcu_barrier)) + return -EBUSY; + + list_del(&s->memcg_params.list); + return 0; +} + void memcg_destroy_kmem_caches(struct mem_cgroup *memcg) { LIST_HEAD(release); @@ -615,14 +617,76 @@ void memcg_destroy_kmem_caches(struct mem_cgroup *memcg) * The cgroup is about to be freed and therefore has no charges * left. Hence, all its caches must be empty by now. */ - BUG_ON(do_kmem_cache_shutdown(s, &release, &need_rcu_barrier)); + BUG_ON(__shutdown_memcg_cache(s, &release, &need_rcu_barrier)); } mutex_unlock(&slab_mutex); put_online_mems(); put_online_cpus(); - do_kmem_cache_release(&release, need_rcu_barrier); + release_caches(&release, need_rcu_barrier); +} + +static int shutdown_memcg_caches(struct kmem_cache *s, + struct list_head *release, bool *need_rcu_barrier) +{ + struct memcg_cache_array *arr; + struct kmem_cache *c, *c2; + LIST_HEAD(busy); + int i; + + BUG_ON(!is_root_cache(s)); + + /* + * First, shutdown active caches, i.e. caches that belong to online + * memory cgroups. + */ + arr = rcu_dereference_protected(s->memcg_params.memcg_caches, + lockdep_is_held(&slab_mutex)); + for_each_memcg_cache_index(i) { + c = arr->entries[i]; + if (!c) + continue; + if (__shutdown_memcg_cache(c, release, need_rcu_barrier)) + /* + * The cache still has objects. Move it to a temporary + * list so as not to try to destroy it for a second + * time while iterating over inactive caches below. + */ + list_move(&c->memcg_params.list, &busy); + else + /* + * The cache is empty and will be destroyed soon. Clear + * the pointer to it in the memcg_caches array so that + * it will never be accessed even if the root cache + * stays alive. + */ + arr->entries[i] = NULL; + } + + /* + * Second, shutdown all caches left from memory cgroups that are now + * offline. + */ + list_for_each_entry_safe(c, c2, &s->memcg_params.list, + memcg_params.list) + __shutdown_memcg_cache(c, release, need_rcu_barrier); + + list_splice(&busy, &s->memcg_params.list); + + /* + * A cache being destroyed must be empty. In particular, this means + * that all per memcg caches attached to it must be empty too. + */ + if (!list_empty(&s->memcg_params.list)) + return -EBUSY; + return 0; +} +#else +static inline int shutdown_memcg_caches(struct kmem_cache *s, + struct list_head *release, bool *need_rcu_barrier) +{ + return 0; } #endif /* CONFIG_MEMCG_KMEM */ @@ -635,16 +699,13 @@ void slab_kmem_cache_release(struct kmem_cache *s) void kmem_cache_destroy(struct kmem_cache *s) { - struct kmem_cache *c, *c2; LIST_HEAD(release); bool need_rcu_barrier = false; - bool busy = false; + int err; if (unlikely(!s)) return; - BUG_ON(!is_root_cache(s)); - get_online_cpus(); get_online_mems(); @@ -654,21 +715,22 @@ void kmem_cache_destroy(struct kmem_cache *s) if (s->refcount) goto out_unlock; - for_each_memcg_cache_safe(c, c2, s) { - if (do_kmem_cache_shutdown(c, &release, &need_rcu_barrier)) - busy = true; - } - - if (!busy) - do_kmem_cache_shutdown(s, &release, &need_rcu_barrier); + err = shutdown_memcg_caches(s, &release, &need_rcu_barrier); + if (!err) + err = shutdown_cache(s, &release, &need_rcu_barrier); + if (err) { + pr_err("kmem_cache_destroy %s: " + "Slab cache still has objects\n", s->name); + dump_stack(); + } out_unlock: mutex_unlock(&slab_mutex); put_online_mems(); put_online_cpus(); - do_kmem_cache_release(&release, need_rcu_barrier); + release_caches(&release, need_rcu_barrier); } EXPORT_SYMBOL(kmem_cache_destroy); @@ -692,7 +754,7 @@ int kmem_cache_shrink(struct kmem_cache *cachep) } EXPORT_SYMBOL(kmem_cache_shrink); -int slab_is_available(void) +bool slab_is_available(void) { return slab_state >= UP; } |