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

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

#ifndef PAGE_FLAGS_H
#define PAGE_FLAGS_H

#include <linux/percpu.h>
#include <linux/cache.h>
#include <linux/types.h>

#include <asm/pgtable.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 if page->private contains a valid value.
 *
 * During disk I/O, PG_locked is used. This bit is set before I/O and
 * reset when I/O completes. page_waitqueue(page) is a wait queue of all tasks
 * waiting for the I/O on this page to complete.
 *
 * 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.
 *
 * For choosing which pages to swap out, inode pages carry a PG_referenced bit,
 * which is set any time the system accesses that page through the (mapping,
 * index) hash table.  This referenced bit, together with the referenced bit
 * in the page tables, is used to manipulate page->age and move the page across
 * the active, inactive_dirty and inactive_clean lists.
 *
 * Note that the referenced bit, the page->lru list_head and the active,
 * inactive_dirty and inactive_clean lists are protected by the
 * zone->lru_lock, and *NOT* by the usual PG_locked bit!
 *
 * 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...
 */

/*
 * 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	/* Has something at ->private */

#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	/* Free, should not be written */
#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

/*
 * Global page accounting.  One instance per CPU.  Only unsigned longs are
 * allowed.
 *
 * - Fields can be modified with xxx_page_state and xxx_page_state_zone at
 * any time safely (which protects the instance from modification by
 * interrupt.
 * - The __xxx_page_state variants can be used safely when interrupts are
 * disabled.
 * - The __xxx_page_state variants can be used if the field is only
 * modified from process context and protected from preemption, or only
 * modified from interrupt context.  In this case, the field should be
 * commented here.
 */
struct page_state {
	unsigned long nr_dirty;		/* Dirty writeable pages */
	unsigned long nr_writeback;	/* Pages under writeback */
	unsigned long nr_unstable;	/* NFS unstable pages */
	unsigned long nr_page_table_pages;/* Pages used for pagetables */
	unsigned long nr_mapped;	/* mapped into pagetables.
					 * only modified from process context */
	unsigned long nr_slab;		/* In slab */
#define GET_PAGE_STATE_LAST nr_slab

	/*
	 * The below are zeroed by get_page_state().  Use get_full_page_state()
	 * to add up all these.
	 */
	unsigned long pgpgin;		/* Disk reads */
	unsigned long pgpgout;		/* Disk writes */
	unsigned long pswpin;		/* swap reads */
	unsigned long pswpout;		/* swap writes */

	unsigned long pgalloc_high;	/* page allocations */
	unsigned long pgalloc_normal;
	unsigned long pgalloc_dma32;
	unsigned long pgalloc_dma;

	unsigned long pgfree;		/* page freeings */
	unsigned long pgactivate;	/* pages moved inactive->active */
	unsigned long pgdeactivate;	/* pages moved active->inactive */

	unsigned long pgfault;		/* faults (major+minor) */
	unsigned long pgmajfault;	/* faults (major only) */

	unsigned long pgrefill_high;	/* inspected in refill_inactive_zone */
	unsigned long pgrefill_normal;
	unsigned long pgrefill_dma32;
	unsigned long pgrefill_dma;

	unsigned long pgsteal_high;	/* total highmem pages reclaimed */
	unsigned long pgsteal_normal;
	unsigned long pgsteal_dma32;
	unsigned long pgsteal_dma;

	unsigned long pgscan_kswapd_high;/* total highmem pages scanned */
	unsigned long pgscan_kswapd_normal;
	unsigned long pgscan_kswapd_dma32;
	unsigned long pgscan_kswapd_dma;

	unsigned long pgscan_direct_high;/* total highmem pages scanned */
	unsigned long pgscan_direct_normal;
	unsigned long pgscan_direct_dma32;
	unsigned long pgscan_direct_dma;

	unsigned long pginodesteal;	/* pages reclaimed via inode freeing */
	unsigned long slabs_scanned;	/* slab objects scanned */
	unsigned long kswapd_steal;	/* pages reclaimed by kswapd */
	unsigned long kswapd_inodesteal;/* reclaimed via kswapd inode freeing */
	unsigned long pageoutrun;	/* kswapd's calls to page reclaim */
	unsigned long allocstall;	/* direct reclaim calls */

	unsigned long pgrotated;	/* pages rotated to tail of the LRU */
	unsigned long nr_bounce;	/* pages for bounce buffers */
};

extern void get_page_state(struct page_state *ret);
extern void get_page_state_node(struct page_state *ret, int node);
extern void get_full_page_state(struct page_state *ret);
extern unsigned long read_page_state_offset(unsigned long offset);
extern void mod_page_state_offset(unsigned long offset, unsigned long delta);
extern void __mod_page_state_offset(unsigned long offset, unsigned long delta);

#define read_page_state(member) \
	read_page_state_offset(offsetof(struct page_state, member))

#define mod_page_state(member, delta)	\
	mod_page_state_offset(offsetof(struct page_state, member), (delta))

#define __mod_page_state(member, delta)	\
	__mod_page_state_offset(offsetof(struct page_state, member), (delta))

#define inc_page_state(member)		mod_page_state(member, 1UL)
#define dec_page_state(member)		mod_page_state(member, 0UL - 1)
#define add_page_state(member,delta)	mod_page_state(member, (delta))
#define sub_page_state(member,delta)	mod_page_state(member, 0UL - (delta))

#define __inc_page_state(member)	__mod_page_state(member, 1UL)
#define __dec_page_state(member)	__mod_page_state(member, 0UL - 1)
#define __add_page_state(member,delta)	__mod_page_state(member, (delta))
#define __sub_page_state(member,delta)	__mod_page_state(member, 0UL - (delta))

#define page_state(member) (*__page_state(offsetof(struct page_state, member)))

#define state_zone_offset(zone, member)					\
({									\
	unsigned offset;						\
	if (is_highmem(zone))						\
		offset = offsetof(struct page_state, member##_high);	\
	else if (is_normal(zone))					\
		offset = offsetof(struct page_state, member##_normal);	\
	else if (is_dma32(zone))					\
		offset = offsetof(struct page_state, member##_dma32);	\
	else								\
		offset = offsetof(struct page_state, member##_dma);	\
	offset;								\
})

#define __mod_page_state_zone(zone, member, delta)			\
 do {									\
	__mod_page_state_offset(state_zone_offset(zone, member), (delta)); \
 } while (0)

#define mod_page_state_zone(zone, member, delta)			\
 do {									\
	mod_page_state_offset(state_zone_offset(zone, member), (delta)); \
 } while (0)

/*
 * 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)
#ifndef SetPageUptodate
#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_page_state(nr_writeback);			\
	} while (0)
#define TestSetPageWriteback(page)					\
	({								\
		int ret;						\
		ret = test_and_set_bit(PG_writeback,			\
					&(page)->flags);		\
		if (!ret)						\
			inc_page_state(nr_writeback);			\
		ret;							\
	})
#define ClearPageWriteback(page)					\
	do {								\
		if (test_and_clear_bit(PG_writeback,			\
				&(page)->flags))			\
			dec_page_state(nr_writeback);			\
	} while (0)
#define TestClearPageWriteback(page)					\
	({								\
		int ret;						\
		ret = test_and_clear_bit(PG_writeback,			\
				&(page)->flags);			\
		if (ret)						\
			dec_page_state(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 */

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

static inline void clear_page_dirty(struct page *page)
{
	test_clear_page_dirty(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
	8	#include <linux/percpu.h>
	9	#include <linux/cache.h>
f886ed44 AM	10	#include <linux/types.h>
f886ed44 AM	11
1da177e4 LT	12	#include <asm/pgtable.h>
	13
	14	/*
	15	* Various page->flags bits:
	16	*
	17	* PG_reserved is set for special pages, which can never be swapped out. Some
	18	* of them might not even exist (eg empty_bad_page)...
	19	*
	20	* The PG_private bitflag is set if page->private contains a valid value.
	21	*
	22	* During disk I/O, PG_locked is used. This bit is set before I/O and
	23	* reset when I/O completes. page_waitqueue(page) is a wait queue of all tasks
	24	* waiting for the I/O on this page to complete.
	25	*
	26	* PG_uptodate tells whether the page's contents is valid. When a read
	27	* completes, the page becomes uptodate, unless a disk I/O error happened.
	28	*
	29	* For choosing which pages to swap out, inode pages carry a PG_referenced bit,
	30	* which is set any time the system accesses that page through the (mapping,
	31	* index) hash table. This referenced bit, together with the referenced bit
	32	* in the page tables, is used to manipulate page->age and move the page across
	33	* the active, inactive_dirty and inactive_clean lists.
	34	*
	35	* Note that the referenced bit, the page->lru list_head and the active,
	36	* inactive_dirty and inactive_clean lists are protected by the
	37	* zone->lru_lock, and NOT by the usual PG_locked bit!
	38	*
	39	* PG_error is set to indicate that an I/O error occurred on this page.
	40	*
	41	* PG_arch_1 is an architecture specific page state bit. The generic code
	42	* guarantees that this bit is cleared for a page when it first is entered into
	43	* the page cache.
	44	*
	45	* PG_highmem pages are not permanently mapped into the kernel virtual address
	46	* space, they need to be kmapped separately for doing IO on the pages. The
	47	* struct page (these bits with information) are always mapped into kernel
	48	* address space...
	49	*/
	50
	51	/*
	52	* Don't use the *_dontuse flags. Use the macros. Otherwise you'll break
91fc8ab3 AW	53	* locked- and dirty-page accounting.
	54	*
	55	* The page flags field is split into two parts, the main flags area
	56	* which extends from the low bits upwards, and the fields area which
	57	* extends from the high bits downwards.
	58	*
	59	* \| FIELD \| ... \| FLAGS \|
	60	* N-1 ^ 0
	61	* (N-FLAGS_RESERVED)
	62	*
	63	* The fields area is reserved for fields mapping zone, node and SPARSEMEM
	64	* section. The boundry between these two areas is defined by
	65	* FLAGS_RESERVED which defines the width of the fields section
	66	* (see linux/mmzone.h). New flags must _not_ overlap with this area.
1da177e4 LT	67	*/
	68	#define PG_locked 0 /* Page is locked. Don't touch. */
	69	#define PG_error 1
	70	#define PG_referenced 2
	71	#define PG_uptodate 3
	72
	73	#define PG_dirty 4
	74	#define PG_lru 5
	75	#define PG_active 6
	76	#define PG_slab 7 /* slab debug (Suparna wants this) */
	77
cbe37d09 BP	78	#define PG_checked 8 /* kill me in 2.5.<early>. */
	79	#define PG_arch_1 9
	80	#define PG_reserved 10
	81	#define PG_private 11 /* Has something at ->private */
	82
	83	#define PG_writeback 12 /* Page is under writeback */
	84	#define PG_nosave 13 /* Used for system suspend/resume */
	85	#define PG_compound 14 /* Part of a compound page */
	86	#define PG_swapcache 15 /* Swap page: swp_entry_t in private */
	87
	88	#define PG_mappedtodisk 16 /* Has blocks allocated on-disk */
	89	#define PG_reclaim 17 /* To be reclaimed asap */
	90	#define PG_nosave_free 18 /* Free, should not be written */
676165a8 NP	91	#define PG_buddy 19 /* Page is free, on buddy lists */
676165a8 NP	92
f886ed44 AM	93
	94	#if (BITS_PER_LONG > 32)
	95	/*
	96	* 64-bit-only flags build down from bit 31
	97	*
	98	* 32 bit -------------------------------\| FIELDS \| FLAGS \|
	99	* 64 bit \| FIELDS \| ?????? FLAGS \|
	100	* 63 32 0
	101	*/
	102	#define PG_uncached 31 /* Page has been mapped as uncached */
	103	#endif
1da177e4 LT	104
	105	/*
	106	* Global page accounting. One instance per CPU. Only unsigned longs are
	107	* allowed.
b09eb1c0 NP	108	*
	109	* - Fields can be modified with xxx_page_state and xxx_page_state_zone at
	110	* any time safely (which protects the instance from modification by
	111	* interrupt.
	112	* - The __xxx_page_state variants can be used safely when interrupts are
	113	* disabled.
	114	* - The __xxx_page_state variants can be used if the field is only
9d414152 NP	115	* modified from process context and protected from preemption, or only
	116	* modified from interrupt context. In this case, the field should be
	117	* commented here.
1da177e4 LT	118	*/
	119	struct page_state {
	120	unsigned long nr_dirty; /* Dirty writeable pages */
	121	unsigned long nr_writeback; /* Pages under writeback */
	122	unsigned long nr_unstable; /* NFS unstable pages */
	123	unsigned long nr_page_table_pages;/* Pages used for pagetables */
b09eb1c0 NP	124	unsigned long nr_mapped; /* mapped into pagetables.
b09eb1c0 NP	125	* only modified from process context */
1da177e4 LT	126	unsigned long nr_slab; /* In slab */
	127	#define GET_PAGE_STATE_LAST nr_slab
	128
	129	/*
	130	* The below are zeroed by get_page_state(). Use get_full_page_state()
	131	* to add up all these.
	132	*/
	133	unsigned long pgpgin; /* Disk reads */
	134	unsigned long pgpgout; /* Disk writes */
	135	unsigned long pswpin; /* swap reads */
	136	unsigned long pswpout; /* swap writes */
1da177e4	137
9328b8fa	138	unsigned long pgalloc_high; /* page allocations */
1da177e4	139	unsigned long pgalloc_normal;
9328b8fa	140	unsigned long pgalloc_dma32;
1da177e4	141	unsigned long pgalloc_dma;
9328b8fa	142
1da177e4 LT	143	unsigned long pgfree; /* page freeings */
	144	unsigned long pgactivate; /* pages moved inactive->active */
	145	unsigned long pgdeactivate; /* pages moved active->inactive */
	146
	147	unsigned long pgfault; /* faults (major+minor) */
	148	unsigned long pgmajfault; /* faults (major only) */
9328b8fa	149
1da177e4 LT	150	unsigned long pgrefill_high; /* inspected in refill_inactive_zone */
1da177e4 LT	151	unsigned long pgrefill_normal;
9328b8fa	152	unsigned long pgrefill_dma32;
1da177e4 LT	153	unsigned long pgrefill_dma;
	154
	155	unsigned long pgsteal_high; /* total highmem pages reclaimed */
	156	unsigned long pgsteal_normal;
9328b8fa	157	unsigned long pgsteal_dma32;
1da177e4	158	unsigned long pgsteal_dma;
9328b8fa	159
1da177e4 LT	160	unsigned long pgscan_kswapd_high;/* total highmem pages scanned */
1da177e4 LT	161	unsigned long pgscan_kswapd_normal;
9328b8fa	162	unsigned long pgscan_kswapd_dma32;
1da177e4	163	unsigned long pgscan_kswapd_dma;
9328b8fa	164
1da177e4 LT	165	unsigned long pgscan_direct_high;/* total highmem pages scanned */
1da177e4 LT	166	unsigned long pgscan_direct_normal;
9328b8fa	167	unsigned long pgscan_direct_dma32;
1da177e4	168	unsigned long pgscan_direct_dma;
1da177e4	169
9328b8fa	170	unsigned long pginodesteal; /* pages reclaimed via inode freeing */
1da177e4 LT	171	unsigned long slabs_scanned; /* slab objects scanned */
	172	unsigned long kswapd_steal; /* pages reclaimed by kswapd */
	173	unsigned long kswapd_inodesteal;/* reclaimed via kswapd inode freeing */
	174	unsigned long pageoutrun; /* kswapd's calls to page reclaim */
	175	unsigned long allocstall; /* direct reclaim calls */
	176
	177	unsigned long pgrotated; /* pages rotated to tail of the LRU */
edfbe2b0	178	unsigned long nr_bounce; /* pages for bounce buffers */
1da177e4 LT	179	};
	180
	181	extern void get_page_state(struct page_state *ret);
c07e02db	182	extern void get_page_state_node(struct page_state *ret, int node);
1da177e4	183	extern void get_full_page_state(struct page_state *ret);
a74609fa NP	184	extern unsigned long read_page_state_offset(unsigned long offset);
	185	extern void mod_page_state_offset(unsigned long offset, unsigned long delta);
	186	extern void __mod_page_state_offset(unsigned long offset, unsigned long delta);
1da177e4 LT	187
1da177e4 LT	188	#define read_page_state(member) \
a74609fa	189	read_page_state_offset(offsetof(struct page_state, member))
1da177e4 LT	190
1da177e4 LT	191	#define mod_page_state(member, delta) \
a74609fa	192	mod_page_state_offset(offsetof(struct page_state, member), (delta))
1da177e4	193
a74609fa NP	194	#define __mod_page_state(member, delta) \
a74609fa NP	195	__mod_page_state_offset(offsetof(struct page_state, member), (delta))
1da177e4	196
a74609fa NP	197	#define inc_page_state(member) mod_page_state(member, 1UL)
	198	#define dec_page_state(member) mod_page_state(member, 0UL - 1)
	199	#define add_page_state(member,delta) mod_page_state(member, (delta))
	200	#define sub_page_state(member,delta) mod_page_state(member, 0UL - (delta))
	201
	202	#define __inc_page_state(member) __mod_page_state(member, 1UL)
	203	#define __dec_page_state(member) __mod_page_state(member, 0UL - 1)
	204	#define __add_page_state(member,delta) __mod_page_state(member, (delta))
	205	#define __sub_page_state(member,delta) __mod_page_state(member, 0UL - (delta))
	206
	207	#define page_state(member) (*__page_state(offsetof(struct page_state, member)))
	208
	209	#define state_zone_offset(zone, member) \
	210	({ \
9328b8fa NP	211	unsigned offset; \
	212	if (is_highmem(zone)) \
	213	offset = offsetof(struct page_state, member##_high); \
	214	else if (is_normal(zone)) \
	215	offset = offsetof(struct page_state, member##_normal); \
	216	else if (is_dma32(zone)) \
	217	offset = offsetof(struct page_state, member##_dma32); \
	218	else \
	219	offset = offsetof(struct page_state, member##_dma); \
a74609fa NP	220	offset; \
	221	})
	222
	223	#define __mod_page_state_zone(zone, member, delta) \
	224	do { \
	225	__mod_page_state_offset(state_zone_offset(zone, member), (delta)); \
	226	} while (0)
	227
	228	#define mod_page_state_zone(zone, member, delta) \
	229	do { \
	230	mod_page_state_offset(state_zone_offset(zone, member), (delta)); \
9328b8fa	231	} while (0)
1da177e4 LT	232
	233	/*
	234	* Manipulation of page state flags
	235	*/
	236	#define PageLocked(page) \
	237	test_bit(PG_locked, &(page)->flags)
	238	#define SetPageLocked(page) \
	239	set_bit(PG_locked, &(page)->flags)
	240	#define TestSetPageLocked(page) \
	241	test_and_set_bit(PG_locked, &(page)->flags)
	242	#define ClearPageLocked(page) \
	243	clear_bit(PG_locked, &(page)->flags)
	244	#define TestClearPageLocked(page) \
	245	test_and_clear_bit(PG_locked, &(page)->flags)
	246
	247	#define PageError(page) test_bit(PG_error, &(page)->flags)
	248	#define SetPageError(page) set_bit(PG_error, &(page)->flags)
	249	#define ClearPageError(page) clear_bit(PG_error, &(page)->flags)
	250
	251	#define PageReferenced(page) test_bit(PG_referenced, &(page)->flags)
	252	#define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags)
	253	#define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags)
	254	#define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags)
	255
	256	#define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags)
	257	#ifndef SetPageUptodate
	258	#define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags)
	259	#endif
	260	#define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags)
	261
	262	#define PageDirty(page) test_bit(PG_dirty, &(page)->flags)
	263	#define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags)
	264	#define TestSetPageDirty(page) test_and_set_bit(PG_dirty, &(page)->flags)
	265	#define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags)
242e5468	266	#define __ClearPageDirty(page) __clear_bit(PG_dirty, &(page)->flags)
1da177e4 LT	267	#define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags)
1da177e4 LT	268
1da177e4	269	#define PageLRU(page) test_bit(PG_lru, &(page)->flags)
8d438f96 NP	270	#define SetPageLRU(page) set_bit(PG_lru, &(page)->flags)
8d438f96 NP	271	#define ClearPageLRU(page) clear_bit(PG_lru, &(page)->flags)
67453911	272	#define __ClearPageLRU(page) __clear_bit(PG_lru, &(page)->flags)
1da177e4 LT	273
	274	#define PageActive(page) test_bit(PG_active, &(page)->flags)
	275	#define SetPageActive(page) set_bit(PG_active, &(page)->flags)
	276	#define ClearPageActive(page) clear_bit(PG_active, &(page)->flags)
67453911	277	#define __ClearPageActive(page) __clear_bit(PG_active, &(page)->flags)
1da177e4 LT	278
1da177e4 LT	279	#define PageSlab(page) test_bit(PG_slab, &(page)->flags)
f205b2fe NP	280	#define __SetPageSlab(page) __set_bit(PG_slab, &(page)->flags)
f205b2fe NP	281	#define __ClearPageSlab(page) __clear_bit(PG_slab, &(page)->flags)
1da177e4 LT	282
1da177e4 LT	283	#ifdef CONFIG_HIGHMEM
cbe37d09	284	#define PageHighMem(page) is_highmem(page_zone(page))
1da177e4 LT	285	#else
	286	#define PageHighMem(page) 0 /* needed to optimize away at compile time */
	287	#endif
	288
	289	#define PageChecked(page) test_bit(PG_checked, &(page)->flags)
	290	#define SetPageChecked(page) set_bit(PG_checked, &(page)->flags)
	291	#define ClearPageChecked(page) clear_bit(PG_checked, &(page)->flags)
	292
	293	#define PageReserved(page) test_bit(PG_reserved, &(page)->flags)
	294	#define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags)
	295	#define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags)
	296	#define __ClearPageReserved(page) __clear_bit(PG_reserved, &(page)->flags)
	297
	298	#define SetPagePrivate(page) set_bit(PG_private, &(page)->flags)
	299	#define ClearPagePrivate(page) clear_bit(PG_private, &(page)->flags)
	300	#define PagePrivate(page) test_bit(PG_private, &(page)->flags)
	301	#define __SetPagePrivate(page) __set_bit(PG_private, &(page)->flags)
	302	#define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags)
	303
	304	#define PageWriteback(page) test_bit(PG_writeback, &(page)->flags)
	305	#define SetPageWriteback(page) \
	306	do { \
	307	if (!test_and_set_bit(PG_writeback, \
	308	&(page)->flags)) \
	309	inc_page_state(nr_writeback); \
	310	} while (0)
	311	#define TestSetPageWriteback(page) \
	312	({ \
	313	int ret; \
	314	ret = test_and_set_bit(PG_writeback, \
	315	&(page)->flags); \
	316	if (!ret) \
	317	inc_page_state(nr_writeback); \
	318	ret; \
	319	})
	320	#define ClearPageWriteback(page) \
	321	do { \
	322	if (test_and_clear_bit(PG_writeback, \
	323	&(page)->flags)) \
	324	dec_page_state(nr_writeback); \
	325	} while (0)
	326	#define TestClearPageWriteback(page) \
	327	({ \
	328	int ret; \
	329	ret = test_and_clear_bit(PG_writeback, \
	330	&(page)->flags); \
	331	if (ret) \
	332	dec_page_state(nr_writeback); \
	333	ret; \
	334	})
	335
	336	#define PageNosave(page) test_bit(PG_nosave, &(page)->flags)
	337	#define SetPageNosave(page) set_bit(PG_nosave, &(page)->flags)
	338	#define TestSetPageNosave(page) test_and_set_bit(PG_nosave, &(page)->flags)
	339	#define ClearPageNosave(page) clear_bit(PG_nosave, &(page)->flags)
	340	#define TestClearPageNosave(page) test_and_clear_bit(PG_nosave, &(page)->flags)
	341
	342	#define PageNosaveFree(page) test_bit(PG_nosave_free, &(page)->flags)
	343	#define SetPageNosaveFree(page) set_bit(PG_nosave_free, &(page)->flags)
	344	#define ClearPageNosaveFree(page) clear_bit(PG_nosave_free, &(page)->flags)
	345
676165a8 NP	346	#define PageBuddy(page) test_bit(PG_buddy, &(page)->flags)
	347	#define __SetPageBuddy(page) __set_bit(PG_buddy, &(page)->flags)
	348	#define __ClearPageBuddy(page) __clear_bit(PG_buddy, &(page)->flags)
	349
1da177e4 LT	350	#define PageMappedToDisk(page) test_bit(PG_mappedtodisk, &(page)->flags)
	351	#define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags)
	352	#define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags)
	353
	354	#define PageReclaim(page) test_bit(PG_reclaim, &(page)->flags)
	355	#define SetPageReclaim(page) set_bit(PG_reclaim, &(page)->flags)
	356	#define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags)
	357	#define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags)
	358
1da177e4	359	#define PageCompound(page) test_bit(PG_compound, &(page)->flags)
5e9dace8 NP	360	#define __SetPageCompound(page) __set_bit(PG_compound, &(page)->flags)
5e9dace8 NP	361	#define __ClearPageCompound(page) __clear_bit(PG_compound, &(page)->flags)
1da177e4 LT	362
	363	#ifdef CONFIG_SWAP
	364	#define PageSwapCache(page) test_bit(PG_swapcache, &(page)->flags)
	365	#define SetPageSwapCache(page) set_bit(PG_swapcache, &(page)->flags)
	366	#define ClearPageSwapCache(page) clear_bit(PG_swapcache, &(page)->flags)
	367	#else
	368	#define PageSwapCache(page) 0
	369	#endif
	370
	371	#define PageUncached(page) test_bit(PG_uncached, &(page)->flags)
	372	#define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags)
	373	#define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags)
	374
	375	struct page; /* forward declaration */
	376
	377	int test_clear_page_dirty(struct page *page);
	378	int test_clear_page_writeback(struct page *page);
	379	int test_set_page_writeback(struct page *page);
	380
	381	static inline void clear_page_dirty(struct page *page)
	382	{
	383	test_clear_page_dirty(page);
	384	}
	385
	386	static inline void set_page_writeback(struct page *page)
	387	{
	388	test_set_page_writeback(page);
	389	}
	390
	391	#endif /* PAGE_FLAGS_H */