mm: memcg/slab: rework non-root kmem_cache lifecycle management

[tomoyo/tomoyo-test1.git] / mm / slab.h

diff --git a/mm/slab.h b/mm/slab.h
index 46623a5..5d2b851 100644 (file)
--- a/mm/slab.h
+++ b/mm/slab.h
@@ -248,31 +248,6 @@ static inline const char *cache_name(struct kmem_cache *s)
        return s->name;
 }
 
-/*
- * Note, we protect with RCU only the memcg_caches array, not per-memcg caches.
- * That said the caller must assure the memcg's cache won't go away by either
- * taking a css reference to the owner cgroup, or holding the slab_mutex.
- */
-static inline struct kmem_cache *
-cache_from_memcg_idx(struct kmem_cache *s, int idx)
-{
-       struct kmem_cache *cachep;
-       struct memcg_cache_array *arr;
-
-       rcu_read_lock();
-       arr = rcu_dereference(s->memcg_params.memcg_caches);
-
-       /*
-        * Make sure we will access the up-to-date value. The code updating
-        * memcg_caches issues a write barrier to match this (see
-        * memcg_create_kmem_cache()).
-        */
-       cachep = READ_ONCE(arr->entries[idx]);
-       rcu_read_unlock();
-
-       return cachep;
-}
-
 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
 {
        if (is_root_cache(s))
@@ -284,14 +259,25 @@ static __always_inline int memcg_charge_slab(struct page *page,
                                             gfp_t gfp, int order,
                                             struct kmem_cache *s)
 {
+       int ret;
+
        if (is_root_cache(s))
                return 0;
-       return memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
+
+       ret = memcg_kmem_charge_memcg(page, gfp, order, s->memcg_params.memcg);
+       if (ret)
+               return ret;
+
+       percpu_ref_get_many(&s->memcg_params.refcnt, 1 << order);
+
+       return 0;
 }
 
 static __always_inline void memcg_uncharge_slab(struct page *page, int order,
                                                struct kmem_cache *s)
 {
+       if (!is_root_cache(s))
+               percpu_ref_put_many(&s->memcg_params.refcnt, 1 << order);
        memcg_kmem_uncharge(page, order);
 }
 
@@ -323,12 +309,6 @@ static inline const char *cache_name(struct kmem_cache *s)
        return s->name;
 }
 
-static inline struct kmem_cache *
-cache_from_memcg_idx(struct kmem_cache *s, int idx)
-{
-       return NULL;
-}
-
 static inline struct kmem_cache *memcg_root_cache(struct kmem_cache *s)
 {
        return s;