Index: linux-2.6.21-rc6/mm/slub.c
===================================================================
--- linux-2.6.21-rc6.orig/mm/slub.c	2007-04-11 14:20:14.000000000 -0700
+++ linux-2.6.21-rc6/mm/slub.c	2007-04-11 14:25:27.000000000 -0700
@@ -181,6 +181,18 @@ static inline struct kmem_cache_node *ge
 #endif
 }
 
+#ifndef CONFIG_SLUB_DEBUG
+
+static inline int debug_slab(struct page *page)
+{
+	return 0;
+}
+
+#else
+static inline int debug_slab(struct page *page)
+{
+	return PageError(page);
+}
 /*
  * Object debugging
  */
@@ -718,6 +730,7 @@ fail:
 	dump_stack();
 	return 0;
 }
+#endif
 
 /*
  * Slab allocation and freeing
@@ -752,7 +765,7 @@ static struct page *allocate_slab(struct
 static void setup_object(struct kmem_cache *s, struct page *page,
 				void *object)
 {
-	if (PageError(page)) {
+	if (debug_slab(page)) {
 		init_object(s, object, 0);
 		init_tracking(s, object);
 	}
@@ -825,7 +838,7 @@ static void __free_slab(struct kmem_cach
 {
 	int pages = 1 << s->order;
 
-	if (unlikely(PageError(page) || s->dtor)) {
+	if (unlikely(debug_slab(page) || s->dtor)) {
 		void *start = page_address(page);
 		void *end = start + (pages << PAGE_SHIFT);
 		void *p;
@@ -1042,7 +1055,7 @@ static void putback_slab(struct kmem_cac
 	if (page->inuse) {
 		if (page->freelist)
 			add_partial(s, page);
-		else if (PageError(page))
+		else if (debug_slab(page))
 			add_full(s, page);
 		slab_unlock(page);
 	} else {
@@ -1179,7 +1192,7 @@ redo:
 	object = page->freelist;
 	if (unlikely(!object))
 		goto another_slab;
-	if (unlikely(PageError(page)))
+	if (unlikely(debug_slab(page)))
 		goto debug;
 
 have_object:
@@ -1274,7 +1287,7 @@ static void slab_free(struct kmem_cache 
 	local_irq_save(flags);
 	slab_lock(page);
 
-	if (unlikely(PageError(page)))
+	if (unlikely(debug_slab(page)))
 		goto debug;
 checks_ok:
 	prior = object[page->offset] = page->freelist;
@@ -1568,6 +1581,9 @@ static int calculate_sizes(struct kmem_c
 	unsigned long size = s->objsize;
 	unsigned long align = s->align;
 
+#ifndef CONFIG_SLAB_DEBUG
+	BUG_ON(flags & DEFAULT_DEBUG_FLAGS);
+#else
 	/*
 	 * Determine if we can poison the object itself. If the user of
 	 * the slab may touch the object after free or before allocation
@@ -1577,6 +1593,7 @@ static int calculate_sizes(struct kmem_c
 			!s->ctor && !s->dtor)
 		flags |= __OBJECT_POISON;
 	else
+#endif
 		flags &= ~__OBJECT_POISON;
 
 	/*
@@ -1615,13 +1632,14 @@ static int calculate_sizes(struct kmem_c
 		s->offset = size;
 		size += sizeof(void *);
 	}
-
+#ifdef CONFIG_SLAB_DEBUG
 	if (flags & SLAB_STORE_USER)
 		/*
 		 * Need to store information about allocs and frees after
 		 * the object.
 		 */
 		size += 2 * sizeof(struct track);
+#endif
 
 	/*
 	 * Determine the alignment based on various parameters that the
@@ -2419,6 +2437,7 @@ void *__kmalloc_node_track_caller(size_t
 
 #ifdef CONFIG_SYSFS
 
+#ifdef CONFIG_SLUB_DEBUG
 static int validate_slab(struct kmem_cache *s, struct page *page)
 {
 	void *p;
@@ -2454,7 +2473,7 @@ static void validate_slab_slab(struct km
 		printk(KERN_INFO "SLUB: %s Skipped busy slab %p\n",
 			s->name, page);
 
-	if (!PageError(page))
+	if (!debug_slab(page))
 		printk(KERN_ERR "SLUB: %s PageError not set on slab %p\n",
 			s->name, page);
 }
@@ -2667,6 +2686,7 @@ static int list_locations(struct kmem_ca
 		n += sprintf(buf, "No data\n");
 	return n;
 }
+#endif
 
 static unsigned long count_partial(struct kmem_cache_node *n)
 {
@@ -2879,6 +2899,7 @@ static ssize_t objects_show(struct kmem_
 }
 SLAB_ATTR_RO(objects);
 
+#ifdef CONFIG_SLAB_DEBUG
 static ssize_t sanity_checks_show(struct kmem_cache *s, char *buf)
 {
 	return sprintf(buf, "%d\n", !!(s->flags & SLAB_DEBUG_FREE));
@@ -2908,6 +2929,7 @@ static ssize_t trace_store(struct kmem_c
 	return length;
 }
 SLAB_ATTR(trace);
+#endif
 
 static ssize_t reclaim_account_show(struct kmem_cache *s, char *buf)
 {
@@ -2945,6 +2967,7 @@ static ssize_t destroy_by_rcu_show(struc
 }
 SLAB_ATTR_RO(destroy_by_rcu);
 
+#ifdef CONFIG_SLUB_DEBUG
 static ssize_t red_zone_show(struct kmem_cache *s, char *buf)
 {
 	return sprintf(buf, "%d\n", !!(s->flags & SLAB_RED_ZONE));
@@ -3033,6 +3056,7 @@ static ssize_t free_calls_show(struct km
 	return list_locations(s, buf, TRACK_FREE);
 }
 SLAB_ATTR_RO(free_calls);
+#endif
 
 #ifdef CONFIG_NUMA
 static ssize_t defrag_ratio_show(struct kmem_cache *s, char *buf)
@@ -3065,17 +3089,21 @@ static struct attribute * slab_attrs[] =
 	&dtor_attr.attr,
 	&aliases_attr.attr,
 	&align_attr.attr,
+#ifdef CONFIG_SLUB_DEBUG
 	&sanity_checks_attr.attr,
 	&trace_attr.attr,
+#endif
 	&hwcache_align_attr.attr,
 	&reclaim_account_attr.attr,
 	&destroy_by_rcu_attr.attr,
+#ifdef CONFIG_SLUB_DEBUG
 	&red_zone_attr.attr,
 	&poison_attr.attr,
 	&store_user_attr.attr,
 	&validate_attr.attr,
 	&alloc_calls_attr.attr,
 	&free_calls_attr.attr,
+#endif
 #ifdef CONFIG_ZONE_DMA
 	&cache_dma_attr.attr,
 #endif