This patch provides kmem_cache_dup(), that duplicates
a cache for a memcg, preserving its creation properties.
Object size, alignment and flags are all respected.
When a duplicate cache is created, the parent cache cannot
be destructed during the child lifetime. To assure this,
its reference count is increased if the cache creation
succeeds.
Signed-off-by: Glauber Costa <glommer@xxxxxxxxxxxxx>
CC: Christoph Lameter <cl@xxxxxxxxx>
CC: Pekka Enberg <penberg@xxxxxxxxxxxxxx>
CC: Michal Hocko <mhocko@xxxxxxx>
CC: Kamezawa Hiroyuki <kamezawa.hiroyu@xxxxxxxxxxxxxx>
CC: Johannes Weiner <hannes@xxxxxxxxxxx>
CC: Suleiman Souhlal <suleiman@xxxxxxxxxx>
---
include/linux/memcontrol.h | 2 ++
include/linux/slab.h | 2 ++
mm/memcontrol.c | 17 +++++++++++++++++
mm/slub.c | 31 +++++++++++++++++++++++++++++++
4 files changed, 52 insertions(+), 0 deletions(-)
diff --git a/include/linux/memcontrol.h b/include/linux/memcontrol.h
index 99e14b9..f93021a 100644
--- a/include/linux/memcontrol.h
+++ b/include/linux/memcontrol.h
@@ -445,6 +445,8 @@ int memcg_css_id(struct mem_cgroup *memcg);
void mem_cgroup_register_cache(struct mem_cgroup *memcg,
struct kmem_cache *s);
void mem_cgroup_release_cache(struct kmem_cache *cachep);
+extern char *mem_cgroup_cache_name(struct mem_cgroup *memcg,
+ struct kmem_cache *cachep);
#else
static inline void mem_cgroup_register_cache(struct mem_cgroup *memcg,
struct kmem_cache *s)
diff --git a/include/linux/slab.h b/include/linux/slab.h
index 1386650..e73ef71 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -322,6 +322,8 @@ extern void *__kmalloc_track_caller(size_t, gfp_t, unsigned long);
#ifdef CONFIG_CGROUP_MEM_RES_CTLR_KMEM
#define MAX_KMEM_CACHE_TYPES 400
+extern struct kmem_cache *kmem_cache_dup(struct mem_cgroup *memcg,
+ struct kmem_cache *cachep);
#else
#define MAX_KMEM_CACHE_TYPES 0
#endif /* CONFIG_CGROUP_MEM_RES_CTLR_KMEM */
diff --git a/mm/memcontrol.c b/mm/memcontrol.c
index 9327996..a8171cb 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;
+}
+
struct ida cache_types;
void mem_cgroup_register_cache(struct mem_cgroup *memcg,
diff --git a/mm/slub.c b/mm/slub.c
index 1698371..9b21b38 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -4034,6 +4034,37 @@ 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);
+
+ /*
+ * We increase the reference counter in the parent cache, to
+ * 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);
+ }
+ kfree(name);
+ return new;
+}
+#endif
+
#ifdef CONFIG_SMP
/*
* Use the cpu notifier to insure that the cpu slabs are flushed when
--
1.7.7.6
--
To unsubscribe, send a message with 'unsubscribe linux-mm' in
the body to majordomo@xxxxxxxxx. For more info on Linux MM,
see: http://www.linux-mm.org/ .
Fight unfair telecom internet charges in Canada: sign http://stopthemeter.ca/
Don't email: <a href=mailto:"dont@xxxxxxxxx";> email@xxxxxxxxx </a>