[linux-2.6-block.git] / include / linux / page_ext.h

#ifndef __LINUX_PAGE_EXT_H
#define __LINUX_PAGE_EXT_H

#include <linux/types.h>
#include <linux/stacktrace.h>

struct pglist_data;
struct page_ext_operations {
	bool (*need)(void);
	void (*init)(void);
};

#ifdef CONFIG_PAGE_EXTENSION

/*
 * page_ext->flags bits:
 *
 * PAGE_EXT_DEBUG_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_ext_flags {
	PAGE_EXT_DEBUG_POISON,		/* Page is poisoned */
	PAGE_EXT_DEBUG_GUARD,
	PAGE_EXT_OWNER,
#if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT)
	PAGE_EXT_YOUNG,
	PAGE_EXT_IDLE,
#endif
};

/*
 * Page Extension can be considered as an extended mem_map.
 * A page_ext page is associated with every page descriptor. The
 * page_ext helps us add more information about the page.
 * All page_ext are allocated at boot or memory hotplug event,
 * then the page_ext for pfn always exists.
 */
struct page_ext {
	unsigned long flags;
#ifdef CONFIG_PAGE_OWNER
	unsigned int order;
	gfp_t gfp_mask;
	unsigned int nr_entries;
	unsigned long trace_entries[8];
#endif
};

extern void pgdat_page_ext_init(struct pglist_data *pgdat);

#ifdef CONFIG_SPARSEMEM
static inline void page_ext_init_flatmem(void)
{
}
extern void page_ext_init(void);
#else
extern void page_ext_init_flatmem(void);
static inline void page_ext_init(void)
{
}
#endif

struct page_ext *lookup_page_ext(struct page *page);

#else /* !CONFIG_PAGE_EXTENSION */
struct page_ext;

static inline void pgdat_page_ext_init(struct pglist_data *pgdat)
{
}

static inline struct page_ext *lookup_page_ext(struct page *page)
{
	return NULL;
}

static inline void page_ext_init(void)
{
}

static inline void page_ext_init_flatmem(void)
{
}
#endif /* CONFIG_PAGE_EXTENSION */
#endif /* __LINUX_PAGE_EXT_H */
Commit	Line	Data
eefa864b JK	1	#ifndef __LINUX_PAGE_EXT_H
	2	#define __LINUX_PAGE_EXT_H
	3
48c96a36 JK	4	#include <linux/types.h>
	5	#include <linux/stacktrace.h>
	6
eefa864b JK	7	struct pglist_data;
	8	struct page_ext_operations {
	9	bool (*need)(void);
	10	void (*init)(void);
	11	};
	12
	13	#ifdef CONFIG_PAGE_EXTENSION
	14
e30825f1 JK	15	/*
	16	* page_ext->flags bits:
	17	*
	18	* PAGE_EXT_DEBUG_POISON is set for poisoned pages. This is used to
	19	* implement generic debug pagealloc feature. The pages are filled with
	20	* poison patterns and set this flag after free_pages(). The poisoned
	21	* pages are verified whether the patterns are not corrupted and clear
	22	* the flag before alloc_pages().
	23	*/
	24
	25	enum page_ext_flags {
	26	PAGE_EXT_DEBUG_POISON, /* Page is poisoned */
	27	PAGE_EXT_DEBUG_GUARD,
48c96a36	28	PAGE_EXT_OWNER,
33c3fc71 VD	29	#if defined(CONFIG_IDLE_PAGE_TRACKING) && !defined(CONFIG_64BIT)
	30	PAGE_EXT_YOUNG,
	31	PAGE_EXT_IDLE,
	32	#endif
e30825f1 JK	33	};
e30825f1 JK	34
eefa864b JK	35	/*
	36	* Page Extension can be considered as an extended mem_map.
	37	* A page_ext page is associated with every page descriptor. The
	38	* page_ext helps us add more information about the page.
	39	* All page_ext are allocated at boot or memory hotplug event,
	40	* then the page_ext for pfn always exists.
	41	*/
	42	struct page_ext {
	43	unsigned long flags;
48c96a36 JK	44	#ifdef CONFIG_PAGE_OWNER
	45	unsigned int order;
	46	gfp_t gfp_mask;
94f759d6	47	unsigned int nr_entries;
48c96a36 JK	48	unsigned long trace_entries[8];
48c96a36 JK	49	#endif
eefa864b JK	50	};
	51
	52	extern void pgdat_page_ext_init(struct pglist_data *pgdat);
	53
	54	#ifdef CONFIG_SPARSEMEM
	55	static inline void page_ext_init_flatmem(void)
	56	{
	57	}
	58	extern void page_ext_init(void);
	59	#else
	60	extern void page_ext_init_flatmem(void);
	61	static inline void page_ext_init(void)
	62	{
	63	}
	64	#endif
	65
	66	struct page_ext lookup_page_ext(struct page page);
	67
	68	#else /* !CONFIG_PAGE_EXTENSION */
	69	struct page_ext;
	70
	71	static inline void pgdat_page_ext_init(struct pglist_data *pgdat)
	72	{
	73	}
	74
	75	static inline struct page_ext lookup_page_ext(struct page page)
	76	{
	77	return NULL;
	78	}
	79
	80	static inline void page_ext_init(void)
	81	{
	82	}
	83
	84	static inline void page_ext_init_flatmem(void)
	85	{
	86	}
	87	#endif /* CONFIG_PAGE_EXTENSION */
	88	#endif /* __LINUX_PAGE_EXT_H */