page-flags.h
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上传日期:2009-04-28
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文件大小:13k
- /*
- * Macros for manipulating and testing page->flags
- */
- #ifndef PAGE_FLAGS_H
- #define PAGE_FLAGS_H
- #include <linux/percpu.h>
- #include <linux/cache.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 top eight bits of page->flags are
- * used for page->zone, so putting flag bits there doesn't work.
- */
- #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_uncached 19 /* Page has been mapped as uncached */
- /*
- * Global page accounting. One instance per CPU. Only unsigned longs are
- * allowed.
- */
- 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 */
- 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(unsigned long offset);
- extern void __mod_page_state(unsigned long offset, unsigned long delta);
- #define read_page_state(member)
- __read_page_state(offsetof(struct page_state, member))
- #define mod_page_state(member, delta)
- __mod_page_state(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 mod_page_state_zone(zone, member, delta)
- do {
- 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
- offset = offsetof(struct page_state, member##_dma);
- __mod_page_state(offset, (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 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 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 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)
- #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 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)
- #ifdef CONFIG_HUGETLB_PAGE
- #define PageCompound(page) test_bit(PG_compound, &(page)->flags)
- #else
- #define PageCompound(page) 0
- #endif
- #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 */