Index: linux-2.6.21-rc4-mm1/include/linux/slub_def.h
===================================================================
--- linux-2.6.21-rc4-mm1.orig/include/linux/slub_def.h	2007-03-21 12:04:00.000000000 -0700
+++ linux-2.6.21-rc4-mm1/include/linux/slub_def.h	2007-03-21 12:05:50.000000000 -0700
@@ -27,15 +27,15 @@ struct kmem_cache {
 	unsigned long flags;
 	int size;		/* Total size of an object */
 	int objects;		/* Number of objects in slab */
-	int align;		/* Alignment */
 	struct kmem_cache_node local_node;
 	int refcount;		/* Refcount for destroy */
 	void (*ctor)(void *, struct kmem_cache *, unsigned long);
 	void (*dtor)(void *, struct kmem_cache *, unsigned long);
 
+	int align;		/* Alignment */
 	int objsize;		/* The size of an object that is in a chunk */
-	int inuse;		/* Used portion of the chunk */
-	const char *name;	/* Name (only for display!) */
+	int inuse;		/* Used portion up to first metadata */
+	const char *name;
 	struct list_head list;	/* List of slabs */
 	struct kobject kobj;	/* For sysfs */
 #ifdef CONFIG_SMP
@@ -47,6 +47,7 @@ struct kmem_cache {
 	struct delayed_work flush;
 #endif
 #ifdef CONFIG_NUMA
+	int defrag_ratio;
 	struct kmem_cache_node *node[MAX_NUMNODES];
 #endif
 	struct page *cpu_slab[NR_CPUS];
Index: linux-2.6.21-rc4-mm1/mm/slub.c
===================================================================
--- linux-2.6.21-rc4-mm1.orig/mm/slub.c	2007-03-21 12:05:59.000000000 -0700
+++ linux-2.6.21-rc4-mm1/mm/slub.c	2007-03-21 12:36:26.000000000 -0700
@@ -63,7 +63,7 @@
 #define SLUB_UNIMPLEMENTED (SLAB_DEBUG_INITIAL)
 
 #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
-				SLAB_POISON)
+				SLAB_POISON | SLAB_STORE_USER)
 /*
  * Set of flags that will prevent slab merging
  */
@@ -385,7 +385,7 @@ static int slab_pad_check(struct kmem_ca
 	u8 *p;
 	int length, remainder;
 
-	if (!s->flags & SLAB_POISON)
+	if (!(s->flags & SLAB_POISON))
 		return 1;
 
 	p = page_address(page);
@@ -895,11 +895,29 @@ out:
 static struct page *get_any_partial(struct kmem_cache *s, gfp_t flags)
 {
 #ifdef CONFIG_NUMA
-	struct zonelist *zonelist = &NODE_DATA(slab_node(current->mempolicy))
-					->node_zonelists[gfp_zone(flags)];
+	struct zonelist *zonelist;
 	struct zone **z;
 	struct page *page;
 
+	/*
+	 * The defrag ratio allows to configure the tradeoffs between
+	 * inter node defragmentation and node local allocations.
+	 * A lower defrag_ratio increases the tendency to do local
+	 * allocations instead of scanning throught the partial
+	 * lists on other nodes.
+	 *
+	 * If defrag_ratio is set to 0 then kmalloc() always
+	 * returns node local objects. If its higher then kmalloc()
+	 * may return off node objects in order to avoid fragmentation.
+	 *
+	 * A higher ratio means slabs may be taken from other nodes
+	 * thus reducing the number of partial slabs on those nodes.
+	 */
+	if (!s->defrag_ratio || get_cycles() % 1024 > s->defrag_ratio)
+		return NULL;
+
+	zonelist = &NODE_DATA(slab_node(current->mempolicy))
+					->node_zonelists[gfp_zone(flags)];
 	for (z = zonelist->zones; *z; z++) {
 		struct kmem_cache_node *n;
 
@@ -1520,6 +1538,9 @@ static int kmem_cache_open(struct kmem_c
 		goto error;
 
 	s->refcount = 1;
+#ifdef CONFIG_NUMA
+	s->defrag_ratio = 100;
+#endif
 
 #ifdef CONFIG_SMP
 	mutex_init(&s->flushing);
@@ -2299,11 +2320,11 @@ struct slab_attribute {
 	__ATTR(_name, 0644, _name##_show, _name##_store)
 
 
-static ssize_t size_show(struct kmem_cache *s, char *buf)
+static ssize_t total_size_show(struct kmem_cache *s, char *buf)
 {
 	return sprintf(buf, "%d\n", s->size);
 }
-SLAB_ATTR_RO(size);
+SLAB_ATTR_RO(total_size);
 
 static ssize_t align_show(struct kmem_cache *s, char *buf)
 {
@@ -2413,7 +2434,6 @@ static ssize_t _trace_show(struct kmem_c
 static ssize_t _trace_store(struct kmem_cache *s, const char *buf, size_t length)
 {
 	s->flags &= ~SLAB_TRACE;
-	printk("_trace_store = %s\n", buf);
 	if (buf[0] == '1')
 		s->flags |= SLAB_TRACE;
 	return length;
@@ -2525,9 +2545,27 @@ static ssize_t _store_user_store(struct 
 }
 SLAB_ATTR(_store_user);
 
+#ifdef CONFIG_NUMA
+static ssize_t _defrag_ratio_show(struct kmem_cache *s, char *buf)
+{
+	return sprintf(buf, "%d\n", s->defrag_ratio / 10);
+}
+
+static ssize_t _defrag_ratio_store(struct kmem_cache *s, const char *buf, size_t length)
+{
+	int n = simple_strtoul(buf, NULL, 10);
+
+	if (n < 100)
+		s->defrag_ratio = n * 10;
+	return length;
+}
+SLAB_ATTR(_defrag_ratio);
+#endif
+
 static struct attribute * slab_attrs[] = {
-	&size_attr.attr,
+	&total_size_attr.attr,
 	&object_size_attr.attr,
+	&align_attr.attr,
 	&objs_per_slab_attr.attr,
 	&order_attr.attr,
 	&objects_attr.attr,
@@ -2549,6 +2587,9 @@ static struct attribute * slab_attrs[] =
 #ifdef CONFIG_CPUSET
 	&_mem_spread_attr.attr,
 #endif
+#ifdef CONFIG_NUMA
+	&_defrag_ratio_attr.attr,
+#endif
 #ifdef CONFIG_ZONE_DMA
 	&_cache_dma_attr.attr,
 #endif