On Fri, 25 May 2012, Glauber Costa wrote:
index dacd1fb..4689034 100644
--- a/mm/memcontrol.c
+++ b/mm/memcontrol.c
@@ -467,6 +467,23 @@ struct cg_proto *tcp_proto_cgroup(struct mem_cgroup *memcg)
EXPORT_SYMBOL(tcp_proto_cgroup);
#endif /* CONFIG_INET */
+char *mem_cgroup_cache_name(struct mem_cgroup *memcg, struct kmem_cache *cachep)
+{
+ char *name;
+ struct dentry *dentry;
+
+ rcu_read_lock();
+ dentry = rcu_dereference(memcg->css.cgroup->dentry);
+ rcu_read_unlock();
+
+ BUG_ON(dentry == NULL);
+
+ name = kasprintf(GFP_KERNEL, "%s(%d:%s)",
+ cachep->name, css_id(&memcg->css), dentry->d_name.name);
+
+ return name;
+}
Function allocates a string that is supposed to be disposed of by the
caller. That needs to be documented and maybe even the name needs to
reflect that.
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4002,6 +4002,38 @@ struct kmem_cache *kmem_cache_create(const char *name, size_t size,
}
EXPORT_SYMBOL(kmem_cache_create);
+#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
+struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
+ struct kmem_cache *s)
+{
+ char *name;
+ struct kmem_cache *new;
+
+ name = mem_cgroup_cache_name(memcg, s);
+ if (!name)
+ return NULL;
+
+ new = kmem_cache_create_memcg(memcg, name, s->objsize, s->align,
+ (s->allocflags& ~SLAB_PANIC), s->ctor);
Hmmm... A full duplicate of the slab cache? We may have many sparsely
used portions of the per node and per cpu structure as a result.
+ * prevent it from being deleted. If kmem_cache_destroy() is
+ * called for the root cache before we call it for a child cache,
+ * it will be queued for destruction when we finally drop the
+ * reference on the child cache.
+ */
+ if (new) {
+ down_write(&slub_lock);
+ s->refcount++;
+ up_write(&slub_lock);
+ }
Why do you need to increase the refcount? You made a full copy right?