diff options
| -rw-r--r-- | include/linux/memcontrol.h | 5 | ||||
| -rw-r--r-- | mm/memcontrol.c | 49 | ||||
| -rw-r--r-- | mm/slab_common.c | 3 |
3 files changed, 55 insertions, 2 deletions
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h index 79fcf0cd718..e119f3ef793 100644 --- a/include/linux/memcontrol.h +++ b/include/linux/memcontrol.h @@ -454,6 +454,7 @@ struct kmem_cache * __memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp); void mem_cgroup_destroy_cache(struct kmem_cache *cachep); +void kmem_cache_destroy_memcg_children(struct kmem_cache *s); /** * memcg_kmem_newpage_charge: verify if a new kmem allocation is allowed. @@ -601,6 +602,10 @@ memcg_kmem_get_cache(struct kmem_cache *cachep, gfp_t gfp) { return cachep; } + +static inline void kmem_cache_destroy_memcg_children(struct kmem_cache *s) +{ +} #endif /* CONFIG_MEMCG_KMEM */ #endif /* _LINUX_MEMCONTROL_H */ diff --git a/mm/memcontrol.c b/mm/memcontrol.c index 270a3678985..4b68ec2c8df 100644 --- a/mm/memcontrol.c +++ b/mm/memcontrol.c @@ -2772,6 +2772,8 @@ static void __mem_cgroup_commit_charge(struct mem_cgroup *memcg, memcg_check_events(memcg, page); } +static DEFINE_MUTEX(set_limit_mutex); + #ifdef CONFIG_MEMCG_KMEM static inline bool memcg_can_account_kmem(struct mem_cgroup *memcg) { @@ -3176,6 +3178,51 @@ out: return new_cachep; } +void kmem_cache_destroy_memcg_children(struct kmem_cache *s) +{ + struct kmem_cache *c; + int i; + + if (!s->memcg_params) + return; + if (!s->memcg_params->is_root_cache) + return; + + /* + * If the cache is being destroyed, we trust that there is no one else + * requesting objects from it. Even if there are, the sanity checks in + * kmem_cache_destroy should caught this ill-case. + * + * Still, we don't want anyone else freeing memcg_caches under our + * noses, which can happen if a new memcg comes to life. As usual, + * we'll take the set_limit_mutex to protect ourselves against this. + */ + mutex_lock(&set_limit_mutex); + for (i = 0; i < memcg_limited_groups_array_size; i++) { + c = s->memcg_params->memcg_caches[i]; + if (!c) + continue; + + /* + * We will now manually delete the caches, so to avoid races + * we need to cancel all pending destruction workers and + * proceed with destruction ourselves. + * + * kmem_cache_destroy() will call kmem_cache_shrink internally, + * and that could spawn the workers again: it is likely that + * the cache still have active pages until this very moment. + * This would lead us back to mem_cgroup_destroy_cache. + * + * But that will not execute at all if the "dead" flag is not + * set, so flip it down to guarantee we are in control. + */ + c->memcg_params->dead = false; + cancel_delayed_work_sync(&c->memcg_params->destroy); + kmem_cache_destroy(c); + } + mutex_unlock(&set_limit_mutex); +} + struct create_work { struct mem_cgroup *memcg; struct kmem_cache *cachep; @@ -4284,8 +4331,6 @@ void mem_cgroup_print_bad_page(struct page *page) } #endif -static DEFINE_MUTEX(set_limit_mutex); - static int mem_cgroup_resize_limit(struct mem_cgroup *memcg, unsigned long long val) { diff --git a/mm/slab_common.c b/mm/slab_common.c index 1c424b6511b..080a43804bf 100644 --- a/mm/slab_common.c +++ b/mm/slab_common.c @@ -249,6 +249,9 @@ EXPORT_SYMBOL(kmem_cache_create); void kmem_cache_destroy(struct kmem_cache *s) { + /* Destroy all the children caches if we aren't a memcg cache */ + kmem_cache_destroy_memcg_children(s); + get_online_cpus(); mutex_lock(&slab_mutex); s->refcount--; |