Index: linux-2.6.21-rc4/include/linux/slub_def.h
===================================================================
--- linux-2.6.21-rc4.orig/include/linux/slub_def.h	2007-03-21 21:06:47.000000000 -0700
+++ linux-2.6.21-rc4/include/linux/slub_def.h	2007-03-21 21:16:58.000000000 -0700
@@ -27,15 +27,15 @@
 	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 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/mm/slub.c
===================================================================
--- linux-2.6.21-rc4.orig/mm/slub.c	2007-03-21 21:16:38.000000000 -0700
+++ linux-2.6.21-rc4/mm/slub.c	2007-03-21 21:19:10.000000000 -0700
@@ -913,11 +913,29 @@
 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;
 
@@ -1536,6 +1554,9 @@
 		goto error;
 
 	s->refcount = 1;
+#ifdef CONFIG_NUMA
+	s->defrag_ratio = 100;
+#endif
 
 #ifdef CONFIG_SMP
 	mutex_init(&s->flushing);
@@ -2521,6 +2541,23 @@
 }
 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[] = {
 	&slab_size_attr.attr,
 	&object_size_attr.attr,
@@ -2545,6 +2582,9 @@
 #ifdef CONFIG_ZONE_DMA
 	&cache_dma_attr.attr,
 #endif
+#ifdef CONFIG_NUMA
+	&defrag_ratio_attr.attr,
+#endif
 	NULL
 };