out_free_cache:
memcg_free_cache_params(s);
- kfree(s);
+ kmem_cache_free(kmem_cache, s);
goto out;
}
}
EXPORT_SYMBOL(kmem_cache_create);
+static int do_kmem_cache_shutdown(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();
+ return -EBUSY;
+ }
+
+ if (s->flags & SLAB_DESTROY_BY_RCU)
+ *need_rcu_barrier = true;
+
+#ifdef CONFIG_MEMCG_KMEM
+ if (!is_root_cache(s)) {
+ struct kmem_cache *root_cache = s->memcg_params->root_cache;
+ int memcg_id = memcg_cache_id(s->memcg_params->memcg);
+
+ BUG_ON(root_cache->memcg_params->memcg_caches[memcg_id] != s);
+ root_cache->memcg_params->memcg_caches[memcg_id] = NULL;
+ }
+#endif
+ list_move(&s->list, release);
+ return 0;
+}
+
+static void do_kmem_cache_release(struct list_head *release,
+ bool need_rcu_barrier)
+{
+ struct kmem_cache *s, *s2;
+
+ if (need_rcu_barrier)
+ rcu_barrier();
+
+ list_for_each_entry_safe(s, s2, release, list) {
+#ifdef SLAB_SUPPORTS_SYSFS
+ sysfs_slab_remove(s);
+#else
+ slab_kmem_cache_release(s);
+#endif
+ }
+}
+
#ifdef CONFIG_MEMCG_KMEM
/*
* memcg_create_kmem_cache - Create a cache for a memory cgroup.
* @memcg: The memory cgroup the new cache is for.
* @root_cache: The parent of the new cache.
- * @memcg_name: The name of the memory cgroup (used for naming the new cache).
*
* This function attempts to create a kmem cache that will serve allocation
* requests going from @memcg to @root_cache. The new cache inherits properties
* from its parent.
*/
-struct kmem_cache *memcg_create_kmem_cache(struct mem_cgroup *memcg,
- struct kmem_cache *root_cache,
- const char *memcg_name)
+void memcg_create_kmem_cache(struct mem_cgroup *memcg,
+ struct kmem_cache *root_cache)
{
+ static char memcg_name_buf[NAME_MAX + 1]; /* protected by slab_mutex */
+ int memcg_id = memcg_cache_id(memcg);
struct kmem_cache *s = NULL;
char *cache_name;
mutex_lock(&slab_mutex);
+ /*
+ * Since per-memcg caches are created asynchronously on first
+ * allocation (see memcg_kmem_get_cache()), several threads can try to
+ * create the same cache, but only one of them may succeed.
+ */
+ if (cache_from_memcg_idx(root_cache, memcg_id))
+ goto out_unlock;
+
+ cgroup_name(mem_cgroup_css(memcg)->cgroup,
+ memcg_name_buf, sizeof(memcg_name_buf));
cache_name = kasprintf(GFP_KERNEL, "%s(%d:%s)", root_cache->name,
- memcg_cache_id(memcg), memcg_name);
+ memcg_cache_id(memcg), memcg_name_buf);
if (!cache_name)
goto out_unlock;
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
+ * cache.
+ */
if (IS_ERR(s)) {
kfree(cache_name);
- s = NULL;
+ goto out_unlock;
}
+ /*
+ * Since readers won't lock (see cache_from_memcg_idx()), we need a
+ * barrier here to ensure nobody will see the kmem_cache partially
+ * initialized.
+ */
+ smp_wmb();
+ root_cache->memcg_params->memcg_caches[memcg_id] = s;
+
out_unlock:
mutex_unlock(&slab_mutex);
put_online_mems();
put_online_cpus();
-
- return s;
}
-static int memcg_cleanup_cache_params(struct kmem_cache *s)
+void memcg_destroy_kmem_caches(struct mem_cgroup *memcg)
{
- int rc;
+ LIST_HEAD(release);
+ bool need_rcu_barrier = false;
+ struct kmem_cache *s, *s2;
- if (!s->memcg_params ||
- !s->memcg_params->is_root_cache)
- return 0;
+ get_online_cpus();
+ get_online_mems();
- mutex_unlock(&slab_mutex);
- rc = __memcg_cleanup_cache_params(s);
mutex_lock(&slab_mutex);
+ list_for_each_entry_safe(s, s2, &slab_caches, list) {
+ if (is_root_cache(s) || s->memcg_params->memcg != memcg)
+ continue;
+ /*
+ * 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));
+ }
+ mutex_unlock(&slab_mutex);
- return rc;
-}
-#else
-static int memcg_cleanup_cache_params(struct kmem_cache *s)
-{
- return 0;
+ put_online_mems();
+ put_online_cpus();
+
+ do_kmem_cache_release(&release, need_rcu_barrier);
}
#endif /* CONFIG_MEMCG_KMEM */
void slab_kmem_cache_release(struct kmem_cache *s)
{
+ memcg_free_cache_params(s);
kfree(s->name);
kmem_cache_free(kmem_cache, s);
}
void kmem_cache_destroy(struct kmem_cache *s)
{
+ int i;
+ LIST_HEAD(release);
+ bool need_rcu_barrier = false;
+ bool busy = false;
+
get_online_cpus();
get_online_mems();
if (s->refcount)
goto out_unlock;
- if (memcg_cleanup_cache_params(s) != 0)
- goto out_unlock;
+ for_each_memcg_cache_index(i) {
+ struct kmem_cache *c = cache_from_memcg_idx(s, i);
- if (__kmem_cache_shutdown(s) != 0) {
- printk(KERN_ERR "kmem_cache_destroy %s: "
- "Slab cache still has objects\n", s->name);
- dump_stack();
- goto out_unlock;
+ if (c && do_kmem_cache_shutdown(c, &release, &need_rcu_barrier))
+ busy = true;
}
- list_del(&s->list);
-
- mutex_unlock(&slab_mutex);
- if (s->flags & SLAB_DESTROY_BY_RCU)
- rcu_barrier();
-
- memcg_free_cache_params(s);
-#ifdef SLAB_SUPPORTS_SYSFS
- sysfs_slab_remove(s);
-#else
- slab_kmem_cache_release(s);
-#endif
- goto out;
+ if (!busy)
+ do_kmem_cache_shutdown(s, &release, &need_rcu_barrier);
out_unlock:
mutex_unlock(&slab_mutex);
-out:
+
put_online_mems();
put_online_cpus();
+
+ do_kmem_cache_release(&release, need_rcu_barrier);
}
EXPORT_SYMBOL(kmem_cache_destroy);
projects / linux-beck.git / blobdiff