#ifndef LINUX_PAGE_DEBUG_FLAGS_H
  #define  LINUX_PAGE_DEBUG_FLAGS_H
  
  /*
   * page->debug_flags bits:
   *
   * PAGE_DEBUG_FLAG_POISON is set for poisoned pages. This is used to
   * implement generic debug pagealloc feature. The pages are filled with
   * poison patterns and set this flag after free_pages(). The poisoned
   * pages are verified whether the patterns are not corrupted and clear
   * the flag before alloc_pages().
   */
  
  enum page_debug_flags {
  	PAGE_DEBUG_FLAG_POISON,		/* Page is poisoned */

  	PAGE_DEBUG_FLAG_GUARD,

  };
  
  /*
   * Ensure that CONFIG_WANT_PAGE_DEBUG_FLAGS reliably
   * gets turned off when no debug features are enabling it!
   */
  
  #ifdef CONFIG_WANT_PAGE_DEBUG_FLAGS

  #if !defined(CONFIG_PAGE_POISONING) && \
      !defined(CONFIG_PAGE_GUARD) \

  /* && !defined(CONFIG_PAGE_DEBUG_SOMETHING_ELSE) && ... */
  #error WANT_PAGE_DEBUG_FLAGS is turned on with no debug features!
  #endif
  #endif /* CONFIG_WANT_PAGE_DEBUG_FLAGS */
  
  #endif /* LINUX_PAGE_DEBUG_FLAGS_H */