Index: linux-2.6.21-rc1/mm/slub.c
===================================================================
--- linux-2.6.21-rc1.orig/mm/slub.c	2007-02-27 13:31:47.000000000 -0800
+++ linux-2.6.21-rc1/mm/slub.c	2007-02-27 13:39:10.000000000 -0800
@@ -119,6 +119,14 @@ struct kmem_cache_node *get_node(struct 
 /*
  * Object debugging
  */
+#define USER_TRACK_DEPTH 3
+
+struct object_meta {
+	void *free_pointer;
+	void *alloc[USER_TRACK_DEPTH];
+	void *free[USER_TRACK_DEPTH];
+}
+
 static void print_section(char *text, u8 *addr, unsigned int length)
 {
 	int i;
@@ -1175,8 +1183,8 @@ int kmem_cache_open(struct kmem_cache *s
 				strlen(slub_debug_slabs)) == 0))
 		flags |= slub_debug;
 
-	if ((flags & SLAB_POISON) && ((flags & SLAB_DESTROY_BY_RCU) ||
-			s->ctor || s->dtor)) {
+	if ((flags & SLAB_POISON) && !(flags & SLAB_DESTROY_BY_RCU) &&
+			!s->ctor && !s->dtor) {
 		if (!(slub_debug & SLAB_POISON))
 			printk(KERN_WARNING "SLUB %s: Clearing SLAB_POISON "
 				"because de/constructor exists.\n",