Merge branch 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux

Pull SLAB changes from Pekka Enberg:
 "Random bug fixes that have accumulated in my inbox over the past few
  months"

* 'slab/next' of git://git.kernel.org/pub/scm/linux/kernel/git/penberg/linux:
  mm: Fix warning on make htmldocs caused by slab.c
  mm: slub: work around unneeded lockdep warning
  mm: sl[uo]b: fix misleading comments
  slub: Fix possible format string bug.
  slub: use lockdep_assert_held
  slub: Fix calculation of cpu slabs
  slab.h: remove duplicate kmalloc declaration and fix kernel-doc warnings

3 files changed, 39 insertions, 27 deletions

diff --git a/include/linux/slab.h b/include/linux/slab.h
index a060142..9260abd 100644
--- a/include/linux/slab.h
+++ b/include/linux/slab.h
@@ -205,8 +205,8 @@ struct kmem_cache {
 
 #ifdef CONFIG_SLUB
 /*
- * SLUB allocates up to order 2 pages directly and otherwise
- * passes the request to the page allocator.
+ * SLUB directly allocates requests fitting in to an order-1 page
+ * (PAGE_SIZE*2).  Larger requests are passed to the page allocator.
  */
 #define KMALLOC_SHIFT_HIGH	(PAGE_SHIFT + 1)
 #define KMALLOC_SHIFT_MAX	(MAX_ORDER + PAGE_SHIFT)
@@ -217,12 +217,12 @@ struct kmem_cache {
 
 #ifdef CONFIG_SLOB
 /*
- * SLOB passes all page size and larger requests to the page allocator.
+ * SLOB passes all requests larger than one page to the page allocator.
  * No kmalloc array is necessary since objects of different sizes can
  * be allocated from the same page.
  */
-#define KMALLOC_SHIFT_MAX	30
 #define KMALLOC_SHIFT_HIGH	PAGE_SHIFT
+#define KMALLOC_SHIFT_MAX	30
 #ifndef KMALLOC_SHIFT_LOW
 #define KMALLOC_SHIFT_LOW	3
 #endif
diff --git a/mm/slab.c b/mm/slab.c
index eb043bf..b264214 100644
--- a/mm/slab.c
+++ b/mm/slab.c
@@ -1946,7 +1946,7 @@ static void slab_destroy_debugcheck(struct kmem_cache *cachep,
 /**
  * slab_destroy - destroy and release all objects in a slab
  * @cachep: cache pointer being destroyed
- * @slabp: slab pointer being destroyed
+ * @page: page pointer being destroyed
  *
  * Destroy all the objs in a slab, and release the mem back to the system.
  * Before calling the slab must have been unlinked from the cache.  The
diff --git a/mm/slub.c b/mm/slub.c
index 2b1a697..7e3e045 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -1000,23 +1000,22 @@ static inline void slab_free_hook(struct kmem_cache *s, void *x)
 
 /*
  * Tracking of fully allocated slabs for debugging purposes.
- *
- * list_lock must be held.
  */
 static void add_full(struct kmem_cache *s,
 	struct kmem_cache_node *n, struct page *page)
 {
+	lockdep_assert_held(&n->list_lock);
+
 	if (!(s->flags & SLAB_STORE_USER))
 		return;
 
 	list_add(&page->lru, &n->full);
 }
 
-/*
- * list_lock must be held.
- */
-static void remove_full(struct kmem_cache *s, struct page *page)
+static void remove_full(struct kmem_cache *s, struct kmem_cache_node *n, struct page *page)
 {
+	lockdep_assert_held(&n->list_lock);
+
 	if (!(s->flags & SLAB_STORE_USER))
 		return;
 
@@ -1265,7 +1264,8 @@ static inline int check_object(struct kmem_cache *s, struct page *page,
 			void *object, u8 val) { return 1; }
 static inline void add_full(struct kmem_cache *s, struct kmem_cache_node *n,
 					struct page *page) {}
-static inline void remove_full(struct kmem_cache *s, struct page *page) {}
+static inline void remove_full(struct kmem_cache *s, struct kmem_cache_node *n,
+					struct page *page) {}
 static inline unsigned long kmem_cache_flags(unsigned long object_size,
 	unsigned long flags, const char *name,
 	void (*ctor)(void *))
@@ -1519,12 +1519,12 @@ static void discard_slab(struct kmem_cache *s, struct page *page)
 
 /*
  * Management of partially allocated slabs.
- *
- * list_lock must be held.
  */
 static inline void add_partial(struct kmem_cache_node *n,
 				struct page *page, int tail)
 {
+	lockdep_assert_held(&n->list_lock);
+
 	n->nr_partial++;
 	if (tail == DEACTIVATE_TO_TAIL)
 		list_add_tail(&page->lru, &n->partial);
@@ -1532,12 +1532,11 @@ static inline void add_partial(struct kmem_cache_node *n,
 		list_add(&page->lru, &n->partial);
 }
 
-/*
- * list_lock must be held.
- */
 static inline void remove_partial(struct kmem_cache_node *n,
 					struct page *page)
 {
+	lockdep_assert_held(&n->list_lock);
+
 	list_del(&page->lru);
 	n->nr_partial--;
 }
@@ -1547,8 +1546,6 @@ static inline void remove_partial(struct kmem_cache_node *n,
  * return the pointer to the freelist.
  *
  * Returns a list of objects or NULL if it fails.
- *
- * Must hold list_lock since we modify the partial list.
  */
 static inline void *acquire_slab(struct kmem_cache *s,
 		struct kmem_cache_node *n, struct page *page,
@@ -1558,6 +1555,8 @@ static inline void *acquire_slab(struct kmem_cache *s,
 	unsigned long counters;
 	struct page new;
 
+	lockdep_assert_held(&n->list_lock);
+
 	/*
 	 * Zap the freelist and set the frozen bit.
 	 * The old freelist is the list of objects for the
@@ -1902,7 +1901,7 @@ redo:
 
 		else if (l == M_FULL)
 
-			remove_full(s, page);
+			remove_full(s, n, page);
 
 		if (m == M_PARTIAL) {
 
@@ -2556,7 +2555,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
 		new.inuse--;
 		if ((!new.inuse || !prior) && !was_frozen) {
 
-			if (kmem_cache_has_cpu_partial(s) && !prior)
+			if (kmem_cache_has_cpu_partial(s) && !prior) {
 
 				/*
 				 * Slab was on no list before and will be
@@ -2566,7 +2565,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
 				 */
 				new.frozen = 1;
 
-			else { /* Needs to be taken off a list */
+			} else { /* Needs to be taken off a list */
 
 	                        n = get_node(s, page_to_nid(page));
 				/*
@@ -2615,7 +2614,7 @@ static void __slab_free(struct kmem_cache *s, struct page *page,
 	 */
 	if (!kmem_cache_has_cpu_partial(s) && unlikely(!prior)) {
 		if (kmem_cache_debug(s))
-			remove_full(s, page);
+			remove_full(s, n, page);
 		add_partial(n, page, DEACTIVATE_TO_TAIL);
 		stat(s, FREE_ADD_PARTIAL);
 	}
@@ -2629,9 +2628,10 @@ slab_empty:
 		 */
 		remove_partial(n, page);
 		stat(s, FREE_REMOVE_PARTIAL);
-	} else
+	} else {
 		/* Slab must be on the full list */
-		remove_full(s, page);
+		remove_full(s, n, page);
+	}
 
 	spin_unlock_irqrestore(&n->list_lock, flags);
 	stat(s, FREE_SLAB);
@@ -2905,7 +2905,13 @@ static void early_kmem_cache_node_alloc(int node)
 	init_kmem_cache_node(n);
 	inc_slabs_node(kmem_cache_node, node, page->objects);
 
+	/*
+	 * the lock is for lockdep's sake, not for any actual
+	 * race protection
+	 */
+	spin_lock(&n->list_lock);
 	add_partial(n, page, DEACTIVATE_TO_HEAD);
+	spin_unlock(&n->list_lock);
 }
 
 static void free_kmem_cache_nodes(struct kmem_cache *s)
@@ -4314,7 +4320,13 @@ static ssize_t show_slab_objects(struct kmem_cache *s,
 
 			page = ACCESS_ONCE(c->partial);
 			if (page) {
-				x = page->pobjects;
+				node = page_to_nid(page);
+				if (flags & SO_TOTAL)
+					WARN_ON_ONCE(1);
+				else if (flags & SO_OBJECTS)
+					WARN_ON_ONCE(1);
+				else
+					x = page->pages;
 				total += x;
 				nodes[node] += x;
 			}
@@ -5178,7 +5190,7 @@ static int sysfs_slab_add(struct kmem_cache *s)
 	}
 
 	s->kobj.kset = slab_kset;
-	err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, name);
+	err = kobject_init_and_add(&s->kobj, &slab_ktype, NULL, "%s", name);
 	if (err) {
 		kobject_put(&s->kobj);
 		return err;