1 files changed, 31 insertions, 95 deletions

diff --git a/mm/slub.c b/mm/slub.c
index 3e8afcc07a7..ae7b9f1ad39 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -169,16 +169,6 @@ static inline bool kmem_cache_has_cpu_partial(struct kmem_cache *s)
  */
 #define DEBUG_METADATA_FLAGS (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
 
-/*
- * Set of flags that will prevent slab merging
- */
-#define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
-		SLAB_TRACE | SLAB_DESTROY_BY_RCU | SLAB_NOLEAKTRACE | \
-		SLAB_FAILSLAB)
-
-#define SLUB_MERGE_SAME (SLAB_DEBUG_FREE | SLAB_RECLAIM_ACCOUNT | \
-		SLAB_CACHE_DMA | SLAB_NOTRACK)
-
 #define OO_SHIFT	16
 #define OO_MASK		((1 << OO_SHIFT) - 1)
 #define MAX_OBJS_PER_PAGE	32767 /* since page.objects is u15 */
@@ -1176,7 +1166,7 @@ out:
 
 __setup("slub_debug", setup_slub_debug);
 
-static unsigned long kmem_cache_flags(unsigned long object_size,
+unsigned long kmem_cache_flags(unsigned long object_size,
 	unsigned long flags, const char *name,
 	void (*ctor)(void *))
 {
@@ -1208,7 +1198,7 @@ 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 kmem_cache_node *n,
 					struct page *page) {}
-static inline unsigned long kmem_cache_flags(unsigned long object_size,
+unsigned long kmem_cache_flags(unsigned long object_size,
 	unsigned long flags, const char *name,
 	void (*ctor)(void *))
 {
@@ -1699,7 +1689,12 @@ static void *get_partial(struct kmem_cache *s, gfp_t flags, int node,
 		struct kmem_cache_cpu *c)
 {
 	void *object;
-	int searchnode = (node == NUMA_NO_NODE) ? numa_mem_id() : node;
+	int searchnode = node;
+
+	if (node == NUMA_NO_NODE)
+		searchnode = numa_mem_id();
+	else if (!node_present_pages(node))
+		searchnode = node_to_mem_node(node);
 
 	object = get_partial_node(s, get_node(s, searchnode), c, flags);
 	if (object || node != NUMA_NO_NODE)
@@ -2280,11 +2275,18 @@ static void *__slab_alloc(struct kmem_cache *s, gfp_t gfpflags, int node,
 redo:
 
 	if (unlikely(!node_match(page, node))) {
-		stat(s, ALLOC_NODE_MISMATCH);
-		deactivate_slab(s, page, c->freelist);
-		c->page = NULL;
-		c->freelist = NULL;
-		goto new_slab;
+		int searchnode = node;
+
+		if (node != NUMA_NO_NODE && !node_present_pages(node))
+			searchnode = node_to_mem_node(node);
+
+		if (unlikely(!node_match(page, searchnode))) {
+			stat(s, ALLOC_NODE_MISMATCH);
+			deactivate_slab(s, page, c->freelist);
+			c->page = NULL;
+			c->freelist = NULL;
+			goto new_slab;
+		}
 	}
 
 	/*
@@ -2707,12 +2709,6 @@ static int slub_max_order = PAGE_ALLOC_COSTLY_ORDER;
 static int slub_min_objects;
 
 /*
- * Merge control. If this is set then no merging of slab caches will occur.
- * (Could be removed. This was introduced to pacify the merge skeptics.)
- */
-static int slub_nomerge;
-
-/*
  * Calculate the order of allocation given an slab object size.
  *
  * The order of allocation has significant impact on performance and other
@@ -3240,14 +3236,6 @@ static int __init setup_slub_min_objects(char *str)
 
 __setup("slub_min_objects=", setup_slub_min_objects);
 
-static int __init setup_slub_nomerge(char *str)
-{
-	slub_nomerge = 1;
-	return 1;
-}
-
-__setup("slub_nomerge", setup_slub_nomerge);
-
 void *__kmalloc(size_t size, gfp_t flags)
 {
 	struct kmem_cache *s;
@@ -3625,69 +3613,6 @@ void __init kmem_cache_init_late(void)
 {
 }
 
-/*
- * Find a mergeable slab cache
- */
-static int slab_unmergeable(struct kmem_cache *s)
-{
-	if (slub_nomerge || (s->flags & SLUB_NEVER_MERGE))
-		return 1;
-
-	if (!is_root_cache(s))
-		return 1;
-
-	if (s->ctor)
-		return 1;
-
-	/*
-	 * We may have set a slab to be unmergeable during bootstrap.
-	 */
-	if (s->refcount < 0)
-		return 1;
-
-	return 0;
-}
-
-static struct kmem_cache *find_mergeable(size_t size, size_t align,
-		unsigned long flags, const char *name, void (*ctor)(void *))
-{
-	struct kmem_cache *s;
-
-	if (slub_nomerge || (flags & SLUB_NEVER_MERGE))
-		return NULL;
-
-	if (ctor)
-		return NULL;
-
-	size = ALIGN(size, sizeof(void *));
-	align = calculate_alignment(flags, align, size);
-	size = ALIGN(size, align);
-	flags = kmem_cache_flags(size, flags, name, NULL);
-
-	list_for_each_entry(s, &slab_caches, list) {
-		if (slab_unmergeable(s))
-			continue;
-
-		if (size > s->size)
-			continue;
-
-		if ((flags & SLUB_MERGE_SAME) != (s->flags & SLUB_MERGE_SAME))
-			continue;
-		/*
-		 * Check if alignment is compatible.
-		 * Courtesy of Adrian Drzewiecki
-		 */
-		if ((s->size & ~(align - 1)) != s->size)
-			continue;
-
-		if (s->size - size >= sizeof(void *))
-			continue;
-
-		return s;
-	}
-	return NULL;
-}
-
 struct kmem_cache *
 __kmem_cache_alias(const char *name, size_t size, size_t align,
 		   unsigned long flags, void (*ctor)(void *))
@@ -4604,6 +4529,14 @@ static ssize_t trace_show(struct kmem_cache *s, char *buf)
 static ssize_t trace_store(struct kmem_cache *s, const char *buf,
 							size_t length)
 {
+	/*
+	 * Tracing a merged cache is going to give confusing results
+	 * as well as cause other issues like converting a mergeable
+	 * cache into an umergeable one.
+	 */
+	if (s->refcount > 1)
+		return -EINVAL;
+
 	s->flags &= ~SLAB_TRACE;
 	if (buf[0] == '1') {
 		s->flags &= ~__CMPXCHG_DOUBLE;
@@ -4721,6 +4654,9 @@ static ssize_t failslab_show(struct kmem_cache *s, char *buf)
 static ssize_t failslab_store(struct kmem_cache *s, const char *buf,
 							size_t length)
 {
+	if (s->refcount > 1)
+		return -EINVAL;
+
 	s->flags &= ~SLAB_FAILSLAB;
 	if (buf[0] == '1')
 		s->flags |= SLAB_FAILSLAB;