bad_range is supposed to be a temporary check. It would be a pity to throw
it out. Make it depend on CONFIG_DEBUG_VM instead.

Index: linux-2.6/mm/page_alloc.c
===================================================================
--- linux-2.6.orig/mm/page_alloc.c
+++ linux-2.6/mm/page_alloc.c
@@ -78,6 +78,7 @@ int min_free_kbytes = 1024;
 unsigned long __initdata nr_kernel_pages;
 unsigned long __initdata nr_all_pages;
 
+#ifdef CONFIG_DEBUG_VM
 static int page_outside_zone_boundaries(struct zone *zone, struct page *page)
 {
 	int ret = 0;
@@ -119,6 +120,13 @@ static int bad_range(struct zone *zone, 
 	return 0;
 }
 
+#else
+static inline int bad_range(struct zone *zone, struct page *page)
+{
+	return 0;
+}
+#endif
+
 static void bad_page(const char *function, struct page *page)
 {
 	printk(KERN_EMERG "Bad page state at %s (in process '%s', page %p)\n",
Index: linux-2.6/lib/Kconfig.debug
===================================================================
--- linux-2.6.orig/lib/Kconfig.debug
+++ linux-2.6/lib/Kconfig.debug
@@ -172,7 +172,8 @@ config DEBUG_VM
 	bool "Debug VM"
 	depends on DEBUG_KERNEL
 	help
-	  Enable this to debug the virtual-memory system.
+	  Enable this to turn on extended checks in the virtual-memory system
+          that may impact performance.
 
 	  If unsure, say N.