#ifndef PAGE_FLAGS_H
#define PAGE_FLAGS_H
-#include <linux/percpu.h>
-#include <linux/cache.h>
-#include <asm/pgtable.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 if page->private contains a valid value.
+ * 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 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.
+ * 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.
*
- * 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_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.
*
* 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 top eight bits of page->flags are
- * used for page->zone, so putting flag bits there doesn't work.
+ * 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_active 6
#define PG_slab 7 /* slab debug (Suparna wants this) */
-#define PG_highmem 8
-#define PG_checked 9 /* kill me in 2.5.<early>. */
-#define PG_arch_1 10
-#define PG_reserved 11
+#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_private 12 /* Has something at ->private */
-#define PG_writeback 13 /* Page is under writeback */
-#define PG_nosave 14 /* Used for system suspend/resume */
-#define PG_maplock 15 /* Lock bit for rmap to ptes */
+#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_swapcache 16 /* Swap page: swp_entry_t in private */
-#define PG_mappedtodisk 17 /* Has blocks allocated on-disk */
-#define PG_reclaim 18 /* To be reclaimed asap */
-#define PG_compound 19 /* Part of a compound page */
-
-#define PG_anon 20 /* Anonymous: anon_vma in mapping */
+#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)
/*
- * Global page accounting. One instance per CPU. Only unsigned longs are
- * allowed.
+ * 64-bit-only flags build down from bit 31
+ *
+ * 32 bit -------------------------------| FIELDS | FLAGS |
+ * 64 bit | FIELDS | ?????? FLAGS |
+ * 63 32 0
*/
-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 */
- 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_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_dma;
-
- unsigned long pgsteal_high; /* total highmem pages reclaimed */
- unsigned long pgsteal_normal;
- unsigned long pgsteal_dma;
- unsigned long pgscan_kswapd_high;/* total highmem pages scanned */
- unsigned long pgscan_kswapd_normal;
-
- unsigned long pgscan_kswapd_dma;
- unsigned long pgscan_direct_high;/* total highmem pages scanned */
- unsigned long pgscan_direct_normal;
- 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 */
-};
-
-DECLARE_PER_CPU(struct page_state, page_states);
-
-extern void get_page_state(struct page_state *ret);
-extern void get_full_page_state(struct page_state *ret);
-extern unsigned long __read_page_state(unsigned offset);
-
-#define read_page_state(member) \
- __read_page_state(offsetof(struct page_state, member))
-
-#define mod_page_state(member, delta) \
- do { \
- unsigned long flags; \
- local_irq_save(flags); \
- __get_cpu_var(page_states).member += (delta); \
- local_irq_restore(flags); \
- } while (0)
-
-
-#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 mod_page_state_zone(zone, member, delta) \
- do { \
- unsigned long flags; \
- local_irq_save(flags); \
- if (is_highmem(zone)) \
- __get_cpu_var(page_states).member##_high += (delta);\
- else if (is_normal(zone)) \
- __get_cpu_var(page_states).member##_normal += (delta);\
- else \
- __get_cpu_var(page_states).member##_dma += (delta);\
- local_irq_restore(flags); \
- } while (0)
+#define PG_uncached 31 /* Page has been mapped as uncached */
+#endif
/*
* Manipulation of page state flags
#define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags)
#define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags)
-#ifndef SetPageUptodate
+#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 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 SetPageLRU(page) set_bit(PG_lru, &(page)->flags)
#define PageLRU(page) test_bit(PG_lru, &(page)->flags)
-#define TestSetPageLRU(page) test_and_set_bit(PG_lru, &(page)->flags)
-#define TestClearPageLRU(page) test_and_clear_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 TestClearPageActive(page) test_and_clear_bit(PG_active, &(page)->flags)
-#define TestSetPageActive(page) test_and_set_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)
-#define TestClearPageSlab(page) test_and_clear_bit(PG_slab, &(page)->flags)
-#define TestSetPageSlab(page) test_and_set_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) test_bit(PG_highmem, &(page)->flags)
+#define PageHighMem(page) is_highmem(page_zone(page))
#else
#define PageHighMem(page) 0 /* needed to optimize away at compile time */
#endif
#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); \
+ inc_zone_page_state(page, NR_WRITEBACK); \
} while (0)
#define TestSetPageWriteback(page) \
({ \
ret = test_and_set_bit(PG_writeback, \
&(page)->flags); \
if (!ret) \
- inc_page_state(nr_writeback); \
+ inc_zone_page_state(page, NR_WRITEBACK); \
ret; \
})
#define ClearPageWriteback(page) \
do { \
if (test_and_clear_bit(PG_writeback, \
&(page)->flags)) \
- dec_page_state(nr_writeback); \
+ dec_zone_page_state(page, NR_WRITEBACK); \
} while (0)
#define TestClearPageWriteback(page) \
({ \
ret = test_and_clear_bit(PG_writeback, \
&(page)->flags); \
if (ret) \
- dec_page_state(nr_writeback); \
+ dec_zone_page_state(page, NR_WRITEBACK); \
ret; \
})
#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 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)
-
-#define PageAnon(page) test_bit(PG_anon, &(page)->flags)
-#define SetPageAnon(page) set_bit(PG_anon, &(page)->flags)
-#define ClearPageAnon(page) clear_bit(PG_anon, &(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 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 __clear_page_dirty(struct page *page);
+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 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);