Linux-2.6.33.2/mm/Kconfig.debug

config DEBUG_PAGEALLOC
	bool "Debug page memory allocations"
	depends on DEBUG_KERNEL && ARCH_SUPPORTS_DEBUG_PAGEALLOC
	depends on !HIBERNATION || !PPC && !SPARC
	depends on !KMEMCHECK
	---help---
	  Unmap pages from the kernel linear mapping after free_pages().
	  This results in a large slowdown, but helps to find certain types
	  of memory corruption.

config WANT_PAGE_DEBUG_FLAGS
	bool

config PAGE_POISONING
	bool "Debug page memory allocations"
	depends on DEBUG_KERNEL && !ARCH_SUPPORTS_DEBUG_PAGEALLOC
	depends on !HIBERNATION
	select DEBUG_PAGEALLOC
	select WANT_PAGE_DEBUG_FLAGS
	---help---
	   Fill the pages with poison patterns after free_pages() and verify
	   the patterns before alloc_pages(). This results in a large slowdown,
	   but helps to find certain types of memory corruption.

	   This option cannot be enabled in combination with hibernation as
	   that would result in incorrect warnings of memory corruption after
	   a resume because free pages are not saved to the suspend image.