mm/Kconfig.debug

   1 config PAGE_EXTENSION
   2         bool "Extend memmap on extra space for more information on page"
   3         ---help---
   4           Extend memmap on extra space for more information on page. This
   5           could be used for debugging features that need to insert extra
   6           field for every page. This extension enables us to save memory
   7           by not allocating this extra memory according to boottime
   8           configuration.
   9
  10 config DEBUG_PAGEALLOC
  11         bool "Debug page memory allocations"
  12         depends on DEBUG_KERNEL
  13         depends on !HIBERNATION || ARCH_SUPPORTS_DEBUG_PAGEALLOC && !PPC && !SPARC
  14         depends on !KMEMCHECK
  15         select PAGE_EXTENSION
  16         select PAGE_POISONING if !ARCH_SUPPORTS_DEBUG_PAGEALLOC
  17         select PAGE_GUARD if ARCH_SUPPORTS_DEBUG_PAGEALLOC
  18         ---help---
  19           Unmap pages from the kernel linear mapping after free_pages().
  20           This results in a large slowdown, but helps to find certain types
  21           of memory corruption.
  22
  23           For architectures which don't enable ARCH_SUPPORTS_DEBUG_PAGEALLOC,
  24           fill the pages with poison patterns after free_pages() and verify
  25           the patterns before alloc_pages().  Additionally,
  26           this option cannot be enabled in combination with hibernation as
  27           that would result in incorrect warnings of memory corruption after
  28           a resume because free pages are not saved to the suspend image.
  29
  30 config WANT_PAGE_DEBUG_FLAGS
  31         bool
  32
  33 config PAGE_POISONING
  34         bool
  35         select WANT_PAGE_DEBUG_FLAGS
  36
  37 config PAGE_GUARD
  38         bool
  39         select WANT_PAGE_DEBUG_FLAGS