diff options
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 183 |
1 files changed, 31 insertions, 152 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 0c076d58c676..4830a3bedfb2 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -5,36 +5,33 @@ #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. + * 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 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. * - * 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_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. * @@ -46,6 +43,10 @@ * 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). + * */ /* @@ -78,7 +79,7 @@ #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_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 */ @@ -87,7 +88,7 @@ #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 */ @@ -103,134 +104,6 @@ #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) \ @@ -254,7 +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) @@ -306,7 +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) \ ({ \ @@ -314,14 +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) \ ({ \ @@ -329,7 +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; \ }) |