[linux.git] / include / linux / page-flags.h

/*
 * Macros for manipulating and testing page->flags
 */

#ifndef PAGE_FLAGS_H
#define PAGE_FLAGS_H

#include <linux/types.h>

/*
 * Various page->flags bits:
 *
 * PG_reserved is set for special pages, which can never be swapped out. Some
 * of them might not even exist (eg empty_bad_page)...
 *
 * The PG_private bitflag is set on pagecache pages if they contain filesystem
 * specific data (which is normally at page->private). It can be used by
 * private allocations for its own usage.
 *
 * During initiation of disk I/O, PG_locked is set. This bit is set before I/O
 * and cleared when writeback _starts_ or when read _completes_. PG_writeback
 * is set before writeback starts and cleared when it finishes.
 *
 * PG_locked also pins a page in pagecache, and blocks truncation of the file
 * while it is held.
 *
 * page_waitqueue(page) is a wait queue of all tasks waiting for the page
 * to become unlocked.
 *
 * PG_uptodate tells whether the page's contents is valid.  When a read
 * completes, the page becomes uptodate, unless a disk I/O error happened.
 *
 * PG_referenced, PG_reclaim are used for page reclaim for anonymous and
 * file-backed pagecache (see mm/vmscan.c).
 *
 * PG_error is set to indicate that an I/O error occurred on this page.
 *
 * PG_arch_1 is an architecture specific page state bit.  The generic code
 * guarantees that this bit is cleared for a page when it first is entered into
 * the page cache.
 *
 * PG_highmem pages are not permanently mapped into the kernel virtual address
 * space, they need to be kmapped separately for doing IO on the pages.  The
 * struct page (these bits with information) are always mapped into kernel
 * address space...
 *
 * PG_buddy is set to indicate that the page is free and in the buddy system
 * (see mm/page_alloc.c).
 *
 */

/*
 * Don't use the *_dontuse flags.  Use the macros.  Otherwise you'll break
 * locked- and dirty-page accounting.
 *
 * The page flags field is split into two parts, the main flags area
 * which extends from the low bits upwards, and the fields area which
 * extends from the high bits downwards.
 *
 *  | FIELD | ... | FLAGS |
 *  N-1     ^             0
 *          (N-FLAGS_RESERVED)
 *
 * The fields area is reserved for fields mapping zone, node and SPARSEMEM
 * section.  The boundry between these two areas is defined by
 * FLAGS_RESERVED which defines the width of the fields section
 * (see linux/mmzone.h).  New flags must _not_ overlap with this area.
 */
#define PG_locked	 	 0	/* Page is locked. Don't touch. */
#define PG_error		 1
#define PG_referenced		 2
#define PG_uptodate		 3

#define PG_dirty	 	 4
#define PG_lru			 5
#define PG_active		 6
#define PG_slab			 7	/* slab debug (Suparna wants this) */

#define PG_checked		 8	/* kill me in 2.5.<early>. */
#define PG_arch_1		 9
#define PG_reserved		10
#define PG_private		11	/* If pagecache, has fs-private data */

#define PG_writeback		12	/* Page is under writeback */
#define PG_nosave		13	/* Used for system suspend/resume */
#define PG_compound		14	/* Part of a compound page */
#define PG_swapcache		15	/* Swap page: swp_entry_t in private */

#define PG_mappedtodisk		16	/* Has blocks allocated on-disk */
#define PG_reclaim		17	/* To be reclaimed asap */
#define PG_nosave_free		18	/* Used for system suspend/resume */
#define PG_buddy		19	/* Page is free, on buddy lists */


#if (BITS_PER_LONG > 32)
/*
 * 64-bit-only flags build down from bit 31
 *
 * 32 bit  -------------------------------| FIELDS |       FLAGS         |
 * 64 bit  |           FIELDS             | ??????         FLAGS         |
 *         63                            32                              0
 */
#define PG_uncached		31	/* Page has been mapped as uncached */
#endif

/*
 * Manipulation of page state flags
 */
#define PageLocked(page)		\
		test_bit(PG_locked, &(page)->flags)
#define SetPageLocked(page)		\
		set_bit(PG_locked, &(page)->flags)
#define TestSetPageLocked(page)		\
		test_and_set_bit(PG_locked, &(page)->flags)
#define ClearPageLocked(page)		\
		clear_bit(PG_locked, &(page)->flags)
#define TestClearPageLocked(page)	\
		test_and_clear_bit(PG_locked, &(page)->flags)

#define PageError(page)		test_bit(PG_error, &(page)->flags)
#define SetPageError(page)	set_bit(PG_error, &(page)->flags)
#define ClearPageError(page)	clear_bit(PG_error, &(page)->flags)

#define PageReferenced(page)	test_bit(PG_referenced, &(page)->flags)
#define SetPageReferenced(page)	set_bit(PG_referenced, &(page)->flags)
#define ClearPageReferenced(page)	clear_bit(PG_referenced, &(page)->flags)
#define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags)

#define PageUptodate(page)	test_bit(PG_uptodate, &(page)->flags)
#ifdef CONFIG_S390
static inline void SetPageUptodate(struct page *page)
{
	if (!test_and_set_bit(PG_uptodate, &page->flags))
		page_test_and_clear_dirty(page);
}
#else
#define SetPageUptodate(page)	set_bit(PG_uptodate, &(page)->flags)
#endif
#define ClearPageUptodate(page)	clear_bit(PG_uptodate, &(page)->flags)

#define PageDirty(page)		test_bit(PG_dirty, &(page)->flags)
#define SetPageDirty(page)	set_bit(PG_dirty, &(page)->flags)
#define TestSetPageDirty(page)	test_and_set_bit(PG_dirty, &(page)->flags)
#define ClearPageDirty(page)	clear_bit(PG_dirty, &(page)->flags)
#define __ClearPageDirty(page)	__clear_bit(PG_dirty, &(page)->flags)
#define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags)

#define PageLRU(page)		test_bit(PG_lru, &(page)->flags)
#define SetPageLRU(page)	set_bit(PG_lru, &(page)->flags)
#define ClearPageLRU(page)	clear_bit(PG_lru, &(page)->flags)
#define __ClearPageLRU(page)	__clear_bit(PG_lru, &(page)->flags)

#define PageActive(page)	test_bit(PG_active, &(page)->flags)
#define SetPageActive(page)	set_bit(PG_active, &(page)->flags)
#define ClearPageActive(page)	clear_bit(PG_active, &(page)->flags)
#define __ClearPageActive(page)	__clear_bit(PG_active, &(page)->flags)

#define PageSlab(page)		test_bit(PG_slab, &(page)->flags)
#define __SetPageSlab(page)	__set_bit(PG_slab, &(page)->flags)
#define __ClearPageSlab(page)	__clear_bit(PG_slab, &(page)->flags)

#ifdef CONFIG_HIGHMEM
#define PageHighMem(page)	is_highmem(page_zone(page))
#else
#define PageHighMem(page)	0 /* needed to optimize away at compile time */
#endif

#define PageChecked(page)	test_bit(PG_checked, &(page)->flags)
#define SetPageChecked(page)	set_bit(PG_checked, &(page)->flags)
#define ClearPageChecked(page)	clear_bit(PG_checked, &(page)->flags)

#define PageReserved(page)	test_bit(PG_reserved, &(page)->flags)
#define SetPageReserved(page)	set_bit(PG_reserved, &(page)->flags)
#define ClearPageReserved(page)	clear_bit(PG_reserved, &(page)->flags)
#define __ClearPageReserved(page)	__clear_bit(PG_reserved, &(page)->flags)

#define SetPagePrivate(page)	set_bit(PG_private, &(page)->flags)
#define ClearPagePrivate(page)	clear_bit(PG_private, &(page)->flags)
#define PagePrivate(page)	test_bit(PG_private, &(page)->flags)
#define __SetPagePrivate(page)  __set_bit(PG_private, &(page)->flags)
#define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags)

#define PageWriteback(page)	test_bit(PG_writeback, &(page)->flags)
#define SetPageWriteback(page)						\
	do {								\
		if (!test_and_set_bit(PG_writeback,			\
				&(page)->flags))			\
			inc_zone_page_state(page, NR_WRITEBACK);	\
	} while (0)
#define TestSetPageWriteback(page)					\
	({								\
		int ret;						\
		ret = test_and_set_bit(PG_writeback,			\
					&(page)->flags);		\
		if (!ret)						\
			inc_zone_page_state(page, NR_WRITEBACK);	\
		ret;							\
	})
#define ClearPageWriteback(page)					\
	do {								\
		if (test_and_clear_bit(PG_writeback,			\
				&(page)->flags))			\
			dec_zone_page_state(page, NR_WRITEBACK);	\
	} while (0)
#define TestClearPageWriteback(page)					\
	({								\
		int ret;						\
		ret = test_and_clear_bit(PG_writeback,			\
				&(page)->flags);			\
		if (ret)						\
			dec_zone_page_state(page, NR_WRITEBACK);	\
		ret;							\
	})

#define PageNosave(page)	test_bit(PG_nosave, &(page)->flags)
#define SetPageNosave(page)	set_bit(PG_nosave, &(page)->flags)
#define TestSetPageNosave(page)	test_and_set_bit(PG_nosave, &(page)->flags)
#define ClearPageNosave(page)		clear_bit(PG_nosave, &(page)->flags)
#define TestClearPageNosave(page)	test_and_clear_bit(PG_nosave, &(page)->flags)

#define PageNosaveFree(page)	test_bit(PG_nosave_free, &(page)->flags)
#define SetPageNosaveFree(page)	set_bit(PG_nosave_free, &(page)->flags)
#define ClearPageNosaveFree(page)		clear_bit(PG_nosave_free, &(page)->flags)

#define PageBuddy(page)		test_bit(PG_buddy, &(page)->flags)
#define __SetPageBuddy(page)	__set_bit(PG_buddy, &(page)->flags)
#define __ClearPageBuddy(page)	__clear_bit(PG_buddy, &(page)->flags)

#define PageMappedToDisk(page)	test_bit(PG_mappedtodisk, &(page)->flags)
#define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags)
#define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags)

#define PageReclaim(page)	test_bit(PG_reclaim, &(page)->flags)
#define SetPageReclaim(page)	set_bit(PG_reclaim, &(page)->flags)
#define ClearPageReclaim(page)	clear_bit(PG_reclaim, &(page)->flags)
#define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags)

#define PageCompound(page)	test_bit(PG_compound, &(page)->flags)
#define __SetPageCompound(page)	__set_bit(PG_compound, &(page)->flags)
#define __ClearPageCompound(page) __clear_bit(PG_compound, &(page)->flags)

#ifdef CONFIG_SWAP
#define PageSwapCache(page)	test_bit(PG_swapcache, &(page)->flags)
#define SetPageSwapCache(page)	set_bit(PG_swapcache, &(page)->flags)
#define ClearPageSwapCache(page) clear_bit(PG_swapcache, &(page)->flags)
#else
#define PageSwapCache(page)	0
#endif

#define PageUncached(page)	test_bit(PG_uncached, &(page)->flags)
#define SetPageUncached(page)	set_bit(PG_uncached, &(page)->flags)
#define ClearPageUncached(page)	clear_bit(PG_uncached, &(page)->flags)

struct page;	/* forward declaration */

extern void cancel_dirty_page(struct page *page, unsigned int account_size);

int test_clear_page_writeback(struct page *page);
int test_set_page_writeback(struct page *page);

static inline void set_page_writeback(struct page *page)
{
	test_set_page_writeback(page);
}

#endif	/* PAGE_FLAGS_H */
Commit	Line	Data
1da177e4 LT	1	/*
	2	* Macros for manipulating and testing page->flags
	3	*/
	4
	5	#ifndef PAGE_FLAGS_H
	6	#define PAGE_FLAGS_H
	7
f886ed44 AM	8	#include <linux/types.h>
f886ed44 AM	9
1da177e4 LT	10	/*
	11	* Various page->flags bits:
	12	*
	13	* PG_reserved is set for special pages, which can never be swapped out. Some
	14	* of them might not even exist (eg empty_bad_page)...
	15	*
da6052f7 NP	16	* The PG_private bitflag is set on pagecache pages if they contain filesystem
	17	* specific data (which is normally at page->private). It can be used by
	18	* private allocations for its own usage.
1da177e4	19	*
da6052f7 NP	20	* During initiation of disk I/O, PG_locked is set. This bit is set before I/O
	21	* and cleared when writeback _starts_ or when read _completes_. PG_writeback
	22	* is set before writeback starts and cleared when it finishes.
	23	*
	24	* PG_locked also pins a page in pagecache, and blocks truncation of the file
	25	* while it is held.
	26	*
	27	* page_waitqueue(page) is a wait queue of all tasks waiting for the page
	28	* to become unlocked.
1da177e4 LT	29	*
	30	* PG_uptodate tells whether the page's contents is valid. When a read
	31	* completes, the page becomes uptodate, unless a disk I/O error happened.
	32	*
da6052f7 NP	33	* PG_referenced, PG_reclaim are used for page reclaim for anonymous and
da6052f7 NP	34	* file-backed pagecache (see mm/vmscan.c).
1da177e4 LT	35	*
	36	* PG_error is set to indicate that an I/O error occurred on this page.
	37	*
	38	* PG_arch_1 is an architecture specific page state bit. The generic code
	39	* guarantees that this bit is cleared for a page when it first is entered into
	40	* the page cache.
	41	*
	42	* PG_highmem pages are not permanently mapped into the kernel virtual address
	43	* space, they need to be kmapped separately for doing IO on the pages. The
	44	* struct page (these bits with information) are always mapped into kernel
	45	* address space...
da6052f7 NP	46	*
	47	* PG_buddy is set to indicate that the page is free and in the buddy system
	48	* (see mm/page_alloc.c).
	49	*
1da177e4 LT	50	*/
	51
	52	/*
	53	* Don't use the *_dontuse flags. Use the macros. Otherwise you'll break
91fc8ab3 AW	54	* locked- and dirty-page accounting.
	55	*
	56	* The page flags field is split into two parts, the main flags area
	57	* which extends from the low bits upwards, and the fields area which
	58	* extends from the high bits downwards.
	59	*
	60	* \| FIELD \| ... \| FLAGS \|
	61	* N-1 ^ 0
	62	* (N-FLAGS_RESERVED)
	63	*
	64	* The fields area is reserved for fields mapping zone, node and SPARSEMEM
	65	* section. The boundry between these two areas is defined by
	66	* FLAGS_RESERVED which defines the width of the fields section
	67	* (see linux/mmzone.h). New flags must _not_ overlap with this area.
1da177e4 LT	68	*/
	69	#define PG_locked 0 /* Page is locked. Don't touch. */
	70	#define PG_error 1
	71	#define PG_referenced 2
	72	#define PG_uptodate 3
	73
	74	#define PG_dirty 4
	75	#define PG_lru 5
	76	#define PG_active 6
	77	#define PG_slab 7 /* slab debug (Suparna wants this) */
	78
cbe37d09 BP	79	#define PG_checked 8 /* kill me in 2.5.<early>. */
	80	#define PG_arch_1 9
	81	#define PG_reserved 10
da6052f7	82	#define PG_private 11 /* If pagecache, has fs-private data */
cbe37d09 BP	83
	84	#define PG_writeback 12 /* Page is under writeback */
	85	#define PG_nosave 13 /* Used for system suspend/resume */
	86	#define PG_compound 14 /* Part of a compound page */
	87	#define PG_swapcache 15 /* Swap page: swp_entry_t in private */
	88
	89	#define PG_mappedtodisk 16 /* Has blocks allocated on-disk */
	90	#define PG_reclaim 17 /* To be reclaimed asap */
da6052f7	91	#define PG_nosave_free 18 /* Used for system suspend/resume */
676165a8 NP	92	#define PG_buddy 19 /* Page is free, on buddy lists */
676165a8 NP	93
f886ed44 AM	94
	95	#if (BITS_PER_LONG > 32)
	96	/*
	97	* 64-bit-only flags build down from bit 31
	98	*
	99	* 32 bit -------------------------------\| FIELDS \| FLAGS \|
	100	* 64 bit \| FIELDS \| ?????? FLAGS \|
	101	* 63 32 0
	102	*/
	103	#define PG_uncached 31 /* Page has been mapped as uncached */
	104	#endif
1da177e4	105
1da177e4 LT	106	/*
	107	* Manipulation of page state flags
	108	*/
	109	#define PageLocked(page) \
	110	test_bit(PG_locked, &(page)->flags)
	111	#define SetPageLocked(page) \
	112	set_bit(PG_locked, &(page)->flags)
	113	#define TestSetPageLocked(page) \
	114	test_and_set_bit(PG_locked, &(page)->flags)
	115	#define ClearPageLocked(page) \
	116	clear_bit(PG_locked, &(page)->flags)
	117	#define TestClearPageLocked(page) \
	118	test_and_clear_bit(PG_locked, &(page)->flags)
	119
	120	#define PageError(page) test_bit(PG_error, &(page)->flags)
	121	#define SetPageError(page) set_bit(PG_error, &(page)->flags)
	122	#define ClearPageError(page) clear_bit(PG_error, &(page)->flags)
	123
	124	#define PageReferenced(page) test_bit(PG_referenced, &(page)->flags)
	125	#define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags)
	126	#define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags)
	127	#define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags)
	128
	129	#define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags)
f6ac2354	130	#ifdef CONFIG_S390
2dcea57a HC	131	static inline void SetPageUptodate(struct page *page)
	132	{
	133	if (!test_and_set_bit(PG_uptodate, &page->flags))
	134	page_test_and_clear_dirty(page);
	135	}
f6ac2354	136	#else
1da177e4 LT	137	#define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags)
	138	#endif
	139	#define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags)
	140
	141	#define PageDirty(page) test_bit(PG_dirty, &(page)->flags)
	142	#define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags)
	143	#define TestSetPageDirty(page) test_and_set_bit(PG_dirty, &(page)->flags)
	144	#define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags)
242e5468	145	#define __ClearPageDirty(page) __clear_bit(PG_dirty, &(page)->flags)
1da177e4 LT	146	#define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags)
1da177e4 LT	147
1da177e4	148	#define PageLRU(page) test_bit(PG_lru, &(page)->flags)
8d438f96 NP	149	#define SetPageLRU(page) set_bit(PG_lru, &(page)->flags)
8d438f96 NP	150	#define ClearPageLRU(page) clear_bit(PG_lru, &(page)->flags)
67453911	151	#define __ClearPageLRU(page) __clear_bit(PG_lru, &(page)->flags)
1da177e4 LT	152
	153	#define PageActive(page) test_bit(PG_active, &(page)->flags)
	154	#define SetPageActive(page) set_bit(PG_active, &(page)->flags)
	155	#define ClearPageActive(page) clear_bit(PG_active, &(page)->flags)
67453911	156	#define __ClearPageActive(page) __clear_bit(PG_active, &(page)->flags)
1da177e4 LT	157
1da177e4 LT	158	#define PageSlab(page) test_bit(PG_slab, &(page)->flags)
f205b2fe NP	159	#define __SetPageSlab(page) __set_bit(PG_slab, &(page)->flags)
f205b2fe NP	160	#define __ClearPageSlab(page) __clear_bit(PG_slab, &(page)->flags)
1da177e4 LT	161
1da177e4 LT	162	#ifdef CONFIG_HIGHMEM
cbe37d09	163	#define PageHighMem(page) is_highmem(page_zone(page))
1da177e4 LT	164	#else
	165	#define PageHighMem(page) 0 /* needed to optimize away at compile time */
	166	#endif
	167
	168	#define PageChecked(page) test_bit(PG_checked, &(page)->flags)
	169	#define SetPageChecked(page) set_bit(PG_checked, &(page)->flags)
	170	#define ClearPageChecked(page) clear_bit(PG_checked, &(page)->flags)
	171
	172	#define PageReserved(page) test_bit(PG_reserved, &(page)->flags)
	173	#define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags)
	174	#define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags)
	175	#define __ClearPageReserved(page) __clear_bit(PG_reserved, &(page)->flags)
	176
	177	#define SetPagePrivate(page) set_bit(PG_private, &(page)->flags)
	178	#define ClearPagePrivate(page) clear_bit(PG_private, &(page)->flags)
	179	#define PagePrivate(page) test_bit(PG_private, &(page)->flags)
	180	#define __SetPagePrivate(page) __set_bit(PG_private, &(page)->flags)
	181	#define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags)
	182
	183	#define PageWriteback(page) test_bit(PG_writeback, &(page)->flags)
	184	#define SetPageWriteback(page) \
	185	do { \
	186	if (!test_and_set_bit(PG_writeback, \
	187	&(page)->flags)) \
ce866b34	188	inc_zone_page_state(page, NR_WRITEBACK); \
1da177e4 LT	189	} while (0)
	190	#define TestSetPageWriteback(page) \
	191	({ \
	192	int ret; \
	193	ret = test_and_set_bit(PG_writeback, \
	194	&(page)->flags); \
	195	if (!ret) \
ce866b34	196	inc_zone_page_state(page, NR_WRITEBACK); \
1da177e4 LT	197	ret; \
	198	})
	199	#define ClearPageWriteback(page) \
	200	do { \
	201	if (test_and_clear_bit(PG_writeback, \
	202	&(page)->flags)) \
ce866b34	203	dec_zone_page_state(page, NR_WRITEBACK); \
1da177e4 LT	204	} while (0)
	205	#define TestClearPageWriteback(page) \
	206	({ \
	207	int ret; \
	208	ret = test_and_clear_bit(PG_writeback, \
	209	&(page)->flags); \
	210	if (ret) \
ce866b34	211	dec_zone_page_state(page, NR_WRITEBACK); \
1da177e4 LT	212	ret; \
	213	})
	214
	215	#define PageNosave(page) test_bit(PG_nosave, &(page)->flags)
	216	#define SetPageNosave(page) set_bit(PG_nosave, &(page)->flags)
	217	#define TestSetPageNosave(page) test_and_set_bit(PG_nosave, &(page)->flags)
	218	#define ClearPageNosave(page) clear_bit(PG_nosave, &(page)->flags)
	219	#define TestClearPageNosave(page) test_and_clear_bit(PG_nosave, &(page)->flags)
	220
	221	#define PageNosaveFree(page) test_bit(PG_nosave_free, &(page)->flags)
	222	#define SetPageNosaveFree(page) set_bit(PG_nosave_free, &(page)->flags)
	223	#define ClearPageNosaveFree(page) clear_bit(PG_nosave_free, &(page)->flags)
	224
676165a8 NP	225	#define PageBuddy(page) test_bit(PG_buddy, &(page)->flags)
	226	#define __SetPageBuddy(page) __set_bit(PG_buddy, &(page)->flags)
	227	#define __ClearPageBuddy(page) __clear_bit(PG_buddy, &(page)->flags)
	228
1da177e4 LT	229	#define PageMappedToDisk(page) test_bit(PG_mappedtodisk, &(page)->flags)
	230	#define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags)
	231	#define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags)
	232
	233	#define PageReclaim(page) test_bit(PG_reclaim, &(page)->flags)
	234	#define SetPageReclaim(page) set_bit(PG_reclaim, &(page)->flags)
	235	#define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags)
	236	#define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags)
	237
1da177e4	238	#define PageCompound(page) test_bit(PG_compound, &(page)->flags)
5e9dace8 NP	239	#define __SetPageCompound(page) __set_bit(PG_compound, &(page)->flags)
5e9dace8 NP	240	#define __ClearPageCompound(page) __clear_bit(PG_compound, &(page)->flags)
1da177e4 LT	241
	242	#ifdef CONFIG_SWAP
	243	#define PageSwapCache(page) test_bit(PG_swapcache, &(page)->flags)
	244	#define SetPageSwapCache(page) set_bit(PG_swapcache, &(page)->flags)
	245	#define ClearPageSwapCache(page) clear_bit(PG_swapcache, &(page)->flags)
	246	#else
	247	#define PageSwapCache(page) 0
	248	#endif
	249
	250	#define PageUncached(page) test_bit(PG_uncached, &(page)->flags)
	251	#define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags)
	252	#define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags)
	253
	254	struct page; /* forward declaration */
	255
fba2591b LT	256	extern void cancel_dirty_page(struct page *page, unsigned int account_size);
fba2591b LT	257
1da177e4 LT	258	int test_clear_page_writeback(struct page *page);
	259	int test_set_page_writeback(struct page *page);
	260
1da177e4 LT	261	static inline void set_page_writeback(struct page *page)
	262	{
	263	test_set_page_writeback(page);
	264	}
	265
	266	#endif /* PAGE_FLAGS_H */