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326 lines
13 KiB
326 lines
13 KiB
/* |
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* Macros for manipulating and testing page->flags |
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*/ |
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#ifndef PAGE_FLAGS_H |
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#define PAGE_FLAGS_H |
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#include <linux/percpu.h> |
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#include <linux/cache.h> |
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#include <asm/pgtable.h> |
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/* |
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* Various page->flags bits: |
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* |
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* PG_reserved is set for special pages, which can never be swapped out. Some |
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* of them might not even exist (eg empty_bad_page)... |
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* |
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* The PG_private bitflag is set if page->private contains a valid value. |
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* |
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* During disk I/O, PG_locked is used. This bit is set before I/O and |
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* reset when I/O completes. page_waitqueue(page) is a wait queue of all tasks |
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* waiting for the I/O on this page to complete. |
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* |
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* PG_uptodate tells whether the page's contents is valid. When a read |
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* completes, the page becomes uptodate, unless a disk I/O error happened. |
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* |
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* For choosing which pages to swap out, inode pages carry a PG_referenced bit, |
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* which is set any time the system accesses that page through the (mapping, |
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* index) hash table. This referenced bit, together with the referenced bit |
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* in the page tables, is used to manipulate page->age and move the page across |
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* the active, inactive_dirty and inactive_clean lists. |
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* |
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* Note that the referenced bit, the page->lru list_head and the active, |
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* inactive_dirty and inactive_clean lists are protected by the |
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* zone->lru_lock, and *NOT* by the usual PG_locked bit! |
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* |
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* PG_error is set to indicate that an I/O error occurred on this page. |
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* |
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* PG_arch_1 is an architecture specific page state bit. The generic code |
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* guarantees that this bit is cleared for a page when it first is entered into |
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* the page cache. |
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* |
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* PG_highmem pages are not permanently mapped into the kernel virtual address |
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* space, they need to be kmapped separately for doing IO on the pages. The |
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* struct page (these bits with information) are always mapped into kernel |
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* address space... |
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*/ |
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/* |
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* Don't use the *_dontuse flags. Use the macros. Otherwise you'll break |
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* locked- and dirty-page accounting. The top eight bits of page->flags are |
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* used for page->zone, so putting flag bits there doesn't work. |
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*/ |
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#define PG_locked 0 /* Page is locked. Don't touch. */ |
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#define PG_error 1 |
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#define PG_referenced 2 |
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#define PG_uptodate 3 |
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#define PG_dirty 4 |
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#define PG_lru 5 |
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#define PG_active 6 |
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#define PG_slab 7 /* slab debug (Suparna wants this) */ |
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#define PG_checked 8 /* kill me in 2.5.<early>. */ |
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#define PG_arch_1 9 |
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#define PG_reserved 10 |
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#define PG_private 11 /* Has something at ->private */ |
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#define PG_writeback 12 /* Page is under writeback */ |
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#define PG_nosave 13 /* Used for system suspend/resume */ |
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#define PG_compound 14 /* Part of a compound page */ |
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#define PG_swapcache 15 /* Swap page: swp_entry_t in private */ |
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#define PG_mappedtodisk 16 /* Has blocks allocated on-disk */ |
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#define PG_reclaim 17 /* To be reclaimed asap */ |
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#define PG_nosave_free 18 /* Free, should not be written */ |
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#define PG_uncached 19 /* Page has been mapped as uncached */ |
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/* |
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* Global page accounting. One instance per CPU. Only unsigned longs are |
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* allowed. |
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*/ |
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struct page_state { |
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unsigned long nr_dirty; /* Dirty writeable pages */ |
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unsigned long nr_writeback; /* Pages under writeback */ |
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unsigned long nr_unstable; /* NFS unstable pages */ |
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unsigned long nr_page_table_pages;/* Pages used for pagetables */ |
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unsigned long nr_mapped; /* mapped into pagetables */ |
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unsigned long nr_slab; /* In slab */ |
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#define GET_PAGE_STATE_LAST nr_slab |
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/* |
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* The below are zeroed by get_page_state(). Use get_full_page_state() |
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* to add up all these. |
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*/ |
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unsigned long pgpgin; /* Disk reads */ |
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unsigned long pgpgout; /* Disk writes */ |
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unsigned long pswpin; /* swap reads */ |
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unsigned long pswpout; /* swap writes */ |
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unsigned long pgalloc_high; /* page allocations */ |
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unsigned long pgalloc_normal; |
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unsigned long pgalloc_dma; |
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unsigned long pgfree; /* page freeings */ |
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unsigned long pgactivate; /* pages moved inactive->active */ |
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unsigned long pgdeactivate; /* pages moved active->inactive */ |
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unsigned long pgfault; /* faults (major+minor) */ |
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unsigned long pgmajfault; /* faults (major only) */ |
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unsigned long pgrefill_high; /* inspected in refill_inactive_zone */ |
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unsigned long pgrefill_normal; |
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unsigned long pgrefill_dma; |
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unsigned long pgsteal_high; /* total highmem pages reclaimed */ |
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unsigned long pgsteal_normal; |
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unsigned long pgsteal_dma; |
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unsigned long pgscan_kswapd_high;/* total highmem pages scanned */ |
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unsigned long pgscan_kswapd_normal; |
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unsigned long pgscan_kswapd_dma; |
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unsigned long pgscan_direct_high;/* total highmem pages scanned */ |
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unsigned long pgscan_direct_normal; |
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unsigned long pgscan_direct_dma; |
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unsigned long pginodesteal; /* pages reclaimed via inode freeing */ |
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unsigned long slabs_scanned; /* slab objects scanned */ |
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unsigned long kswapd_steal; /* pages reclaimed by kswapd */ |
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unsigned long kswapd_inodesteal;/* reclaimed via kswapd inode freeing */ |
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unsigned long pageoutrun; /* kswapd's calls to page reclaim */ |
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unsigned long allocstall; /* direct reclaim calls */ |
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unsigned long pgrotated; /* pages rotated to tail of the LRU */ |
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unsigned long nr_bounce; /* pages for bounce buffers */ |
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}; |
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extern void get_page_state(struct page_state *ret); |
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extern void get_page_state_node(struct page_state *ret, int node); |
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extern void get_full_page_state(struct page_state *ret); |
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extern unsigned long __read_page_state(unsigned long offset); |
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extern void __mod_page_state(unsigned long offset, unsigned long delta); |
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#define read_page_state(member) \ |
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__read_page_state(offsetof(struct page_state, member)) |
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#define mod_page_state(member, delta) \ |
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__mod_page_state(offsetof(struct page_state, member), (delta)) |
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#define inc_page_state(member) mod_page_state(member, 1UL) |
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#define dec_page_state(member) mod_page_state(member, 0UL - 1) |
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#define add_page_state(member,delta) mod_page_state(member, (delta)) |
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#define sub_page_state(member,delta) mod_page_state(member, 0UL - (delta)) |
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#define mod_page_state_zone(zone, member, delta) \ |
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do { \ |
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unsigned offset; \ |
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if (is_highmem(zone)) \ |
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offset = offsetof(struct page_state, member##_high); \ |
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else if (is_normal(zone)) \ |
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offset = offsetof(struct page_state, member##_normal); \ |
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else \ |
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offset = offsetof(struct page_state, member##_dma); \ |
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__mod_page_state(offset, (delta)); \ |
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} while (0) |
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/* |
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* Manipulation of page state flags |
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*/ |
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#define PageLocked(page) \ |
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test_bit(PG_locked, &(page)->flags) |
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#define SetPageLocked(page) \ |
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set_bit(PG_locked, &(page)->flags) |
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#define TestSetPageLocked(page) \ |
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test_and_set_bit(PG_locked, &(page)->flags) |
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#define ClearPageLocked(page) \ |
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clear_bit(PG_locked, &(page)->flags) |
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#define TestClearPageLocked(page) \ |
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test_and_clear_bit(PG_locked, &(page)->flags) |
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#define PageError(page) test_bit(PG_error, &(page)->flags) |
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#define SetPageError(page) set_bit(PG_error, &(page)->flags) |
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#define ClearPageError(page) clear_bit(PG_error, &(page)->flags) |
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#define PageReferenced(page) test_bit(PG_referenced, &(page)->flags) |
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#define SetPageReferenced(page) set_bit(PG_referenced, &(page)->flags) |
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#define ClearPageReferenced(page) clear_bit(PG_referenced, &(page)->flags) |
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#define TestClearPageReferenced(page) test_and_clear_bit(PG_referenced, &(page)->flags) |
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#define PageUptodate(page) test_bit(PG_uptodate, &(page)->flags) |
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#ifndef SetPageUptodate |
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#define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags) |
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#endif |
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#define ClearPageUptodate(page) clear_bit(PG_uptodate, &(page)->flags) |
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#define PageDirty(page) test_bit(PG_dirty, &(page)->flags) |
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#define SetPageDirty(page) set_bit(PG_dirty, &(page)->flags) |
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#define TestSetPageDirty(page) test_and_set_bit(PG_dirty, &(page)->flags) |
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#define ClearPageDirty(page) clear_bit(PG_dirty, &(page)->flags) |
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#define __ClearPageDirty(page) __clear_bit(PG_dirty, &(page)->flags) |
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#define TestClearPageDirty(page) test_and_clear_bit(PG_dirty, &(page)->flags) |
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#define SetPageLRU(page) set_bit(PG_lru, &(page)->flags) |
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#define PageLRU(page) test_bit(PG_lru, &(page)->flags) |
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#define TestSetPageLRU(page) test_and_set_bit(PG_lru, &(page)->flags) |
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#define TestClearPageLRU(page) test_and_clear_bit(PG_lru, &(page)->flags) |
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#define PageActive(page) test_bit(PG_active, &(page)->flags) |
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#define SetPageActive(page) set_bit(PG_active, &(page)->flags) |
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#define ClearPageActive(page) clear_bit(PG_active, &(page)->flags) |
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#define TestClearPageActive(page) test_and_clear_bit(PG_active, &(page)->flags) |
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#define TestSetPageActive(page) test_and_set_bit(PG_active, &(page)->flags) |
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#define PageSlab(page) test_bit(PG_slab, &(page)->flags) |
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#define SetPageSlab(page) set_bit(PG_slab, &(page)->flags) |
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#define ClearPageSlab(page) clear_bit(PG_slab, &(page)->flags) |
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#define TestClearPageSlab(page) test_and_clear_bit(PG_slab, &(page)->flags) |
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#define TestSetPageSlab(page) test_and_set_bit(PG_slab, &(page)->flags) |
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#ifdef CONFIG_HIGHMEM |
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#define PageHighMem(page) is_highmem(page_zone(page)) |
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#else |
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#define PageHighMem(page) 0 /* needed to optimize away at compile time */ |
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#endif |
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#define PageChecked(page) test_bit(PG_checked, &(page)->flags) |
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#define SetPageChecked(page) set_bit(PG_checked, &(page)->flags) |
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#define ClearPageChecked(page) clear_bit(PG_checked, &(page)->flags) |
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#define PageReserved(page) test_bit(PG_reserved, &(page)->flags) |
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#define SetPageReserved(page) set_bit(PG_reserved, &(page)->flags) |
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#define ClearPageReserved(page) clear_bit(PG_reserved, &(page)->flags) |
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#define __ClearPageReserved(page) __clear_bit(PG_reserved, &(page)->flags) |
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#define SetPagePrivate(page) set_bit(PG_private, &(page)->flags) |
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#define ClearPagePrivate(page) clear_bit(PG_private, &(page)->flags) |
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#define PagePrivate(page) test_bit(PG_private, &(page)->flags) |
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#define __SetPagePrivate(page) __set_bit(PG_private, &(page)->flags) |
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#define __ClearPagePrivate(page) __clear_bit(PG_private, &(page)->flags) |
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#define PageWriteback(page) test_bit(PG_writeback, &(page)->flags) |
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#define SetPageWriteback(page) \ |
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do { \ |
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if (!test_and_set_bit(PG_writeback, \ |
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&(page)->flags)) \ |
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inc_page_state(nr_writeback); \ |
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} while (0) |
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#define TestSetPageWriteback(page) \ |
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({ \ |
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int ret; \ |
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ret = test_and_set_bit(PG_writeback, \ |
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&(page)->flags); \ |
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if (!ret) \ |
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inc_page_state(nr_writeback); \ |
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ret; \ |
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}) |
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#define ClearPageWriteback(page) \ |
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do { \ |
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if (test_and_clear_bit(PG_writeback, \ |
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&(page)->flags)) \ |
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dec_page_state(nr_writeback); \ |
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} while (0) |
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#define TestClearPageWriteback(page) \ |
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({ \ |
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int ret; \ |
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ret = test_and_clear_bit(PG_writeback, \ |
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&(page)->flags); \ |
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if (ret) \ |
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dec_page_state(nr_writeback); \ |
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ret; \ |
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}) |
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#define PageNosave(page) test_bit(PG_nosave, &(page)->flags) |
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#define SetPageNosave(page) set_bit(PG_nosave, &(page)->flags) |
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#define TestSetPageNosave(page) test_and_set_bit(PG_nosave, &(page)->flags) |
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#define ClearPageNosave(page) clear_bit(PG_nosave, &(page)->flags) |
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#define TestClearPageNosave(page) test_and_clear_bit(PG_nosave, &(page)->flags) |
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#define PageNosaveFree(page) test_bit(PG_nosave_free, &(page)->flags) |
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#define SetPageNosaveFree(page) set_bit(PG_nosave_free, &(page)->flags) |
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#define ClearPageNosaveFree(page) clear_bit(PG_nosave_free, &(page)->flags) |
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#define PageMappedToDisk(page) test_bit(PG_mappedtodisk, &(page)->flags) |
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#define SetPageMappedToDisk(page) set_bit(PG_mappedtodisk, &(page)->flags) |
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#define ClearPageMappedToDisk(page) clear_bit(PG_mappedtodisk, &(page)->flags) |
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#define PageReclaim(page) test_bit(PG_reclaim, &(page)->flags) |
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#define SetPageReclaim(page) set_bit(PG_reclaim, &(page)->flags) |
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#define ClearPageReclaim(page) clear_bit(PG_reclaim, &(page)->flags) |
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#define TestClearPageReclaim(page) test_and_clear_bit(PG_reclaim, &(page)->flags) |
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#ifdef CONFIG_HUGETLB_PAGE |
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#define PageCompound(page) test_bit(PG_compound, &(page)->flags) |
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#else |
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#define PageCompound(page) 0 |
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#endif |
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#define SetPageCompound(page) set_bit(PG_compound, &(page)->flags) |
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#define ClearPageCompound(page) clear_bit(PG_compound, &(page)->flags) |
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#ifdef CONFIG_SWAP |
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#define PageSwapCache(page) test_bit(PG_swapcache, &(page)->flags) |
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#define SetPageSwapCache(page) set_bit(PG_swapcache, &(page)->flags) |
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#define ClearPageSwapCache(page) clear_bit(PG_swapcache, &(page)->flags) |
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#else |
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#define PageSwapCache(page) 0 |
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#endif |
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#define PageUncached(page) test_bit(PG_uncached, &(page)->flags) |
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#define SetPageUncached(page) set_bit(PG_uncached, &(page)->flags) |
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#define ClearPageUncached(page) clear_bit(PG_uncached, &(page)->flags) |
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struct page; /* forward declaration */ |
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int test_clear_page_dirty(struct page *page); |
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int test_clear_page_writeback(struct page *page); |
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int test_set_page_writeback(struct page *page); |
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static inline void clear_page_dirty(struct page *page) |
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{ |
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test_clear_page_dirty(page); |
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} |
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static inline void set_page_writeback(struct page *page) |
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{ |
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test_set_page_writeback(page); |
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} |
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#endif /* PAGE_FLAGS_H */
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