Index: linux-2.6.21-rc1/include/linux/slab.h
===================================================================
--- linux-2.6.21-rc1.orig/include/linux/slab.h	2007-02-26 13:50:38.000000000 -0800
+++ linux-2.6.21-rc1/include/linux/slab.h	2007-02-26 13:51:01.000000000 -0800
@@ -32,6 +32,7 @@
 #define SLAB_PANIC		0x00040000UL	/* Panic if kmem_cache_create() fails */
 #define SLAB_DESTROY_BY_RCU	0x00080000UL	/* Defer freeing slabs to RCU */
 #define SLAB_MEM_SPREAD		0x00100000UL	/* Spread some memory over cpuset */
+#define SLAB_TRACE		0x00200000UL	/* Trace allocations and frees */
 
 /* Flags passed to a constructor functions */
 #define SLAB_CTOR_CONSTRUCTOR	0x001UL		/* If not set, then deconstructor */
Index: linux-2.6.21-rc1/mm/slub.c
===================================================================
--- linux-2.6.21-rc1.orig/mm/slub.c	2007-02-26 13:51:05.000000000 -0800
+++ linux-2.6.21-rc1/mm/slub.c	2007-02-26 14:53:16.000000000 -0800
@@ -50,8 +50,7 @@
 /*
  * Flags from the regular SLAB that SLUB does not support:
  */
-#define SLUB_UNIMPLEMENTED (SLAB_DEBUG_INITIAL | \
-	SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER)
+#define SLUB_UNIMPLEMENTED (SLAB_DEBUG_INITIAL | SLAB_STORE_USER)
 
 #define DEBUG_DEFAULT_FLAGS (SLAB_DEBUG_FREE | SLAB_RED_ZONE | \
 				SLAB_STORE_USER | SLAB_POISON)
@@ -59,7 +58,8 @@
  * Set of flags that will prevent slab merging
  */
 #define SLUB_NEVER_MERGE (SLAB_RED_ZONE | SLAB_POISON | SLAB_STORE_USER | \
-	SLAB_DESTROY_BY_RCU | SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA)
+	SLAB_DESTROY_BY_RCU | SLAB_RECLAIM_ACCOUNT | SLAB_CACHE_DMA | \
+	SLAB_TRACE)
 
 #ifndef ARCH_KMALLOC_MINALIGN
 #define ARCH_KMALLOC_MINALIGN sizeof(void *)
@@ -249,7 +249,6 @@
 
 static void init_object(struct kmem_cache *s, void *object, int active)
 {
-#if 0
 	u8 *p = object;
 
 	if (s->flags & SLAB_POISON) {
@@ -261,7 +260,6 @@
 		memset(p + s->objsize,
 			active ? RED_ACTIVE : RED_INACTIVE,
 			s->inuse - s->objsize);
-#endif
 }
 
 static int check_bytes(u8 *start, unsigned int value, unsigned int bytes)
@@ -278,7 +276,6 @@
 static int check_object(struct kmem_cache *s, struct page *page,
 					void *object, int active)
 {
-#if 0
 	u8 *p = object;
 
 	if (s->flags & SLAB_RED_ZONE)
@@ -294,7 +291,6 @@
 			object_err(s, page, p, "Poison");
 			return 0;
 		}
-#endif
 	return 1;
 }
 
@@ -556,7 +552,7 @@
 	page->slab = s;
 	page->flags |= 1 << PG_slab;
 	if (s->flags & (SLAB_DEBUG_FREE | SLAB_RED_ZONE | SLAB_POISON |
-			SLAB_STORE_USER) || s->objects == 1)
+			SLAB_STORE_USER | SLAB_TRACE) || s->objects == 1)
 		page->flags |= 1 << PG_error;
 
 	if (s->objects > 1) {
@@ -739,6 +735,13 @@
 		if (!check_object(s, page, object, 0))
 			dump_stack();
 		init_object(s, object, 1);
+		if (s->flags & SLAB_TRACE) {
+			printk("SLUB-Trace %s alloc node=%d gfp=%4lx "
+				"object=%p slab=%p inuse=%d freelist=%p\n",
+				s->name, node, (unsigned long)gfpflags,
+				object, page, page->inuse, page->freelist);
+			dump_stack();
+		}
 	}
 	return object;
 
@@ -830,6 +833,14 @@
 			goto dumpret;
 		if (!check_object(s, page, object, 1))
 			goto dumpret;
+		if (s->flags & SLAB_TRACE) {
+			printk("SLUB-Trace %s free object=%p slab=%p"
+				"inuse=%d freelist=%p\n",
+				s->name, object, page, page->inuse,
+				page->freelist);
+			print_section("SLUB-Trace", x, min(s->objsize, 128));
+			dump_stack();
+		}
 		init_object(s, object, 0);
 	}
 
@@ -1091,12 +1102,9 @@
 	/* Enable debugging if selected on the kernel commandline */
 	if (slub_debug && (!slub_debug_slabs ||
 			strncmp(slub_debug_slabs, name,
-				strlen(slub_debug_slabs) == 0)))
+				strlen(slub_debug_slabs)) == 0))
 		flags |= slub_debug;
 
-	printk("kmem_cache_open %s slub_debug=%lx slub_debug_slabs=%s flags=%lx\n", name,
-			slub_debug,slub_debug_slabs, flags);
-
 	s->name = name;
 	s->ctor = ctor;
 	s->dtor = dtor;
@@ -1349,12 +1357,11 @@
 
 static int __init setup_slub_debug(char *str)
 {
-	if (!str)
+	if (!str || *str != '=')
 		slub_debug = DEBUG_DEFAULT_FLAGS;
-	else
-	if (*str == '=') {
+	else {
 		str++;
-		if (!*str || *str == ',')
+		if (*str == 0 || *str == ',')
 			slub_debug = DEBUG_DEFAULT_FLAGS;
 		else
 		for( ;str && *str != ','; str++)
@@ -1363,13 +1370,14 @@
 			case 'z' : case 'Z' : slub_debug |= SLAB_RED_ZONE;break;
 			case 'p' : case 'P' : slub_debug |= SLAB_POISON;break;
 			case 'u' : case 'U' : slub_debug |= SLAB_STORE_USER;break;
+			case 't' : case 'T' : slub_debug |= SLAB_TRACE;break;
 			default:
 				printk(KERN_CRIT "slub_debug option '%c' unknown. skipped\n",*str);
 			}
 	}
+
 	if (*str == ',')
 		slub_debug_slabs = str + 1;
-	printk("setup_slub_debug slub_debug=%lx slub_debug_slabs=%s\n", slub_debug,slub_debug_slabs);
 	return 1;
 }
 
@@ -1760,6 +1768,8 @@
 		*d++ = 'Z';
 	if (s->flags & SLAB_POISON)
 		*d++ = 'P';
+	if (s->flags & SLAB_TRACE)
+		*d++ = 'T';
 
 	*d = 0;