|  | #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 */ | 
|  | }; | 
|  |  | 
|  | /* | 
|  | * 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_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 */ |