diff --git a/arch/x86_64/mm/pageattr.c b/arch/x86_64/mm/pageattr.c
index 836c218..cd8499c 100644
--- a/arch/x86_64/mm/pageattr.c
+++ b/arch/x86_64/mm/pageattr.c
@@ -112,7 +112,14 @@ static inline void save_page(struct page *fpage, int data)
 			return;
 		SetPageFlush(fpage);
 	}
+	printk("ADD (%s): E=%p, H=%p, H->N=%p, N->P=%p, N->N=%p; PREV0=%p, "
+			"NEXT0=%p, ",
+			current->comm, &fpage->lru,
+			&deferred_pages, deferred_pages.next,
+			deferred_pages.next->prev, deferred_pages.next->next,
+			fpage->lru.prev, fpage->lru.next);
 	list_add(&fpage->lru, &deferred_pages);
+	printk("PREV1=%p, NEXT1=%p\n", fpage->lru.prev, fpage->lru.next);
 }
 
 /* 
@@ -274,6 +281,7 @@ void global_flush_tlb(void)
 	down_read(&init_mm.mmap_sem);
 	arg.full_flush = full_flush;
 	full_flush = 0;
+	printk("FLUSH\n");
 	list_replace_init(&deferred_pages, &arg.l);
 	up_read(&init_mm.mmap_sem);
 
diff --git a/include/linux/list.h b/include/linux/list.h
index f29fc9c..1add963 100644
--- a/include/linux/list.h
+++ b/include/linux/list.h
@@ -265,6 +265,8 @@ static inline void list_del_init(struct list_head *entry)
 static inline void list_move(struct list_head *list, struct list_head *head)
 {
 	__list_del(list->prev, list->next);
+	list->next = LIST_POISON1;
+	list->prev = LIST_POISON2;
 	list_add(list, head);
 }
 
@@ -277,6 +279,8 @@ static inline void list_move_tail(struct list_head *list,
 				  struct list_head *head)
 {
 	__list_del(list->prev, list->next);
+	list->next = LIST_POISON1;
+	list->prev = LIST_POISON2;
 	list_add_tail(list, head);
 }
 
diff --git a/lib/list_debug.c b/lib/list_debug.c
index 4350ba9..57573d5 100644
--- a/lib/list_debug.c
+++ b/lib/list_debug.c
@@ -15,15 +15,34 @@
  * This is only for internal list manipulation where we know
  * the prev/next entries already!
  */
-
+#include <linux/sched.h>
 void __list_add(struct list_head *new,
 			      struct list_head *prev,
 			      struct list_head *next)
 {
+	static unsigned int a, b;
+	unsigned long off;
+
+	if (unlikely(!a && current && current->comm[0] == 'X'))
+		a++;
+
+	if (unlikely(a && !b && (void *)new >= (void *)mem_map &&
+		(void *)new < (void *)(mem_map + 1048576) &&
+		(new->prev != LIST_POISON2 || new->next != LIST_POISON1) &&
+		(new->prev != NULL || new->next != NULL) &&
+		(new->prev != new || new->next != new))) {
+		off = ((void *)new - (void *)mem_map) % sizeof(struct page);
+		if (off == offsetof(struct page, lru)) {
+			printk(KERN_DEBUG "POISONS (%p): "
+					"%p, %p\n", new, new->prev, new->next);
+			dump_stack();
+		}
+	}
 	if (unlikely(next->prev != prev)) {
 		printk(KERN_ERR "list_add corruption. next->prev should be "
 			"prev (%p), but was %p. (next=%p).\n",
 			prev, next->prev, next);
+		b++;
 		BUG();
 	}
 	if (unlikely(prev->next != next)) {
diff --git a/mm/slub.c b/mm/slub.c
index ac4f157..8aec6aa 100644
--- a/mm/slub.c
+++ b/mm/slub.c
@@ -2680,6 +2680,7 @@ int kmem_cache_shrink(struct kmem_cache *s)
 				slab_unlock(page);
 				discard_slab(s, page);
 			} else {
+				printk("MOVE: %p\n", &page->lru);
 				list_move(&page->lru,
 				slabs_by_inuse + page->inuse);
 			}