X-Git-Url: http://git.onelab.eu/?a=blobdiff_plain;f=include%2Flinux%2Fpage-flags.h;h=350878a2d848cf2efe561449ac7d9ccece15630b;hb=refs%2Fheads%2Fvserver;hp=d7ce72e433b4ff07977d758d68f966b1fb4436e9;hpb=76828883507a47dae78837ab5dec5a5b4513c667;p=linux-2.6.git diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index d7ce72e43..350878a2d 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -5,9 +5,7 @@ #ifndef PAGE_FLAGS_H #define PAGE_FLAGS_H -#include -#include -#include +#include /* * Various page->flags bits: @@ -15,24 +13,25 @@ * 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. * @@ -44,12 +43,28 @@ * 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 @@ -64,7 +79,7 @@ #define PG_checked 8 /* kill me in 2.5.. */ #define PG_arch_1 9 #define PG_reserved 10 -#define PG_private 11 /* Has something at ->private */ +#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 */ @@ -73,137 +88,20 @@ #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_nosave_free 18 /* Used for system suspend/resume */ #define PG_buddy 19 /* Page is free, on buddy lists */ -#define PG_uncached 20 /* Page has been mapped as uncached */ +#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 * - * - 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, or only modified from interrupt context. - * In this case, the field should be commented here. + * 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. - * 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) +#define PG_uncached 31 /* Page has been mapped as uncached */ +#endif /* * Manipulation of page state flags @@ -229,7 +127,13 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta); #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) @@ -241,22 +145,19 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta); #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) is_highmem(page_zone(page)) @@ -284,7 +185,7 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta); 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) \ ({ \ @@ -292,14 +193,14 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta); 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) \ ({ \ @@ -307,7 +208,7 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta); ret = test_and_clear_bit(PG_writeback, \ &(page)->flags); \ if (ret) \ - dec_page_state(nr_writeback); \ + dec_zone_page_state(page, NR_WRITEBACK); \ ret; \ }) @@ -335,8 +236,8 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta); #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 __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) @@ -352,15 +253,11 @@ extern void __mod_page_state_offset(unsigned long offset, unsigned long delta); struct page; /* forward declaration */ -int test_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);