linux_old1/mm/Kconfig.debug

config DEBUG_PAGEALLOC
	bool "Debug page memory allocations"
	depends on DEBUG_KERNEL
	depends on !HIBERNATION || ARCH_SUPPORTS_DEBUG_PAGEALLOC && !PPC && !SPARC
	depends on !KMEMCHECK
	select PAGE_POISONING if !ARCH_SUPPORTS_DEBUG_PAGEALLOC
	select PAGE_GUARD if ARCH_SUPPORTS_DEBUG_PAGEALLOC
	---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.

	  For architectures which don't enable ARCH_SUPPORTS_DEBUG_PAGEALLOC,
	  fill the pages with poison patterns after free_pages() and verify
	  the patterns before alloc_pages().  Additionally,
	  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.

config WANT_PAGE_DEBUG_FLAGS
	bool

config PAGE_POISONING
	bool
	select WANT_PAGE_DEBUG_FLAGS

config PAGE_GUARD
	bool
	select WANT_PAGE_DEBUG_FLAGS