---
 mm/slub.c |   19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)

Index: linux-2.6/mm/slub.c
===================================================================
--- linux-2.6.orig/mm/slub.c	2007-12-21 14:51:03.242407195 -0800
+++ linux-2.6/mm/slub.c	2007-12-21 15:06:52.145123303 -0800
@@ -1581,6 +1581,15 @@ void *kmem_cache_alloc_node(struct kmem_
 EXPORT_SYMBOL(kmem_cache_alloc_node);
 #endif
 
+static void rcu_free_object(struct rcu_head *h)
+{
+	struct page *page = virt_to_head_page(h);
+	struct kmem_cache *s = page->slab;
+	void ** object = (void *)h - s->offset;
+
+	kfree(object);
+}
+
 /*
  * Slow patch handling. This may still be called frequently since objects
  * have a longer lifetime than the cpu slabs in most processing loads.
@@ -1595,7 +1604,13 @@ static void __slab_free(struct kmem_cach
 	void *prior;
 	void **object = (void *)x;
 
-	slab_lock(page);
+	if (unlikely(!slab_trylock(page))) {
+		/* Free via RCU since the slab is contended */
+		struct rcu_head *h = (void *)(object + offset);
+
+		call_rcu(h, rcu_free_object);
+		return;
+	}
 
 	if (unlikely(SlabDebug(page)))
 		goto debug;
@@ -2142,7 +2157,7 @@ static int calculate_sizes(struct kmem_c
 		 * destructor or are poisoning the objects.
 		 */
 		s->offset = size;
-		size += sizeof(void *);
+		size += sizeof(struct rcu_head);
 	}
 
 #ifdef CONFIG_SLUB_DEBUG