diff options
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 319 |
1 files changed, 159 insertions, 160 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index b5b30f1c1e5..590cff32415 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -6,7 +6,10 @@ #define PAGE_FLAGS_H #include <linux/types.h> +#ifndef __GENERATING_BOUNDS_H #include <linux/mm_types.h> +#include <linux/bounds.h> +#endif /* !__GENERATING_BOUNDS_H */ /* * Various page->flags bits: @@ -59,77 +62,138 @@ * extends from the high bits downwards. * * | FIELD | ... | FLAGS | - * N-1 ^ 0 - * (N-FLAGS_RESERVED) + * N-1 ^ 0 + * (NR_PAGEFLAGS) * - * 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. + * The fields area is reserved for fields mapping zone, node (for NUMA) and + * SPARSEMEM section (for variants of SPARSEMEM that require section ids like + * SPARSEMEM_EXTREME with !SPARSEMEM_VMEMMAP). */ -#define PG_locked 0 /* Page is locked. Don't touch. */ -#define PG_error 1 -#define PG_referenced 2 -#define PG_uptodate 3 +enum pageflags { + PG_locked, /* Page is locked. Don't touch. */ + PG_error, + PG_referenced, + PG_uptodate, + PG_dirty, + PG_lru, + PG_active, + PG_slab, + PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/ + PG_arch_1, + PG_reserved, + PG_private, /* If pagecache, has fs-private data */ + PG_writeback, /* Page is under writeback */ +#ifdef CONFIG_PAGEFLAGS_EXTENDED + PG_head, /* A head page */ + PG_tail, /* A tail page */ +#else + PG_compound, /* A compound page */ +#endif + PG_swapcache, /* Swap page: swp_entry_t in private */ + PG_mappedtodisk, /* Has blocks allocated on-disk */ + PG_reclaim, /* To be reclaimed asap */ + PG_buddy, /* Page is free, on buddy lists */ +#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR + PG_uncached, /* Page has been mapped as uncached */ +#endif + __NR_PAGEFLAGS +}; + +#ifndef __GENERATING_BOUNDS_H + +/* + * Macros to create function definitions for page flags + */ +#define TESTPAGEFLAG(uname, lname) \ +static inline int Page##uname(struct page *page) \ + { return test_bit(PG_##lname, &page->flags); } -#define PG_dirty 4 -#define PG_lru 5 -#define PG_active 6 -#define PG_slab 7 /* slab debug (Suparna wants this) */ +#define SETPAGEFLAG(uname, lname) \ +static inline void SetPage##uname(struct page *page) \ + { set_bit(PG_##lname, &page->flags); } -#define PG_owner_priv_1 8 /* Owner use. If pagecache, fs may use*/ -#define PG_arch_1 9 -#define PG_reserved 10 -#define PG_private 11 /* If pagecache, has fs-private data */ +#define CLEARPAGEFLAG(uname, lname) \ +static inline void ClearPage##uname(struct page *page) \ + { clear_bit(PG_##lname, &page->flags); } -#define PG_writeback 12 /* Page is under writeback */ -#define PG_compound 14 /* Part of a compound page */ -#define PG_swapcache 15 /* Swap page: swp_entry_t in private */ +#define __SETPAGEFLAG(uname, lname) \ +static inline void __SetPage##uname(struct page *page) \ + { __set_bit(PG_##lname, &page->flags); } -#define PG_mappedtodisk 16 /* Has blocks allocated on-disk */ -#define PG_reclaim 17 /* To be reclaimed asap */ -#define PG_buddy 19 /* Page is free, on buddy lists */ +#define __CLEARPAGEFLAG(uname, lname) \ +static inline void __ClearPage##uname(struct page *page) \ + { __clear_bit(PG_##lname, &page->flags); } + +#define TESTSETFLAG(uname, lname) \ +static inline int TestSetPage##uname(struct page *page) \ + { return test_and_set_bit(PG_##lname, &page->flags); } + +#define TESTCLEARFLAG(uname, lname) \ +static inline int TestClearPage##uname(struct page *page) \ + { return test_and_clear_bit(PG_##lname, &page->flags); } -/* PG_readahead is only used for file reads; PG_reclaim is only for writes */ -#define PG_readahead PG_reclaim /* Reminder to do async read-ahead */ -/* PG_owner_priv_1 users should have descriptive aliases */ -#define PG_checked PG_owner_priv_1 /* Used by some filesystems */ -#define PG_pinned PG_owner_priv_1 /* Xen pinned pagetable */ +#define PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \ + SETPAGEFLAG(uname, lname) CLEARPAGEFLAG(uname, lname) + +#define __PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \ + __SETPAGEFLAG(uname, lname) __CLEARPAGEFLAG(uname, lname) + +#define PAGEFLAG_FALSE(uname) \ +static inline int Page##uname(struct page *page) \ + { return 0; } + +#define TESTSCFLAG(uname, lname) \ + TESTSETFLAG(uname, lname) TESTCLEARFLAG(uname, lname) + +struct page; /* forward declaration */ + +PAGEFLAG(Locked, locked) TESTSCFLAG(Locked, locked) +PAGEFLAG(Error, error) +PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced) +PAGEFLAG(Dirty, dirty) TESTSCFLAG(Dirty, dirty) __CLEARPAGEFLAG(Dirty, dirty) +PAGEFLAG(LRU, lru) __CLEARPAGEFLAG(LRU, lru) +PAGEFLAG(Active, active) __CLEARPAGEFLAG(Active, active) +__PAGEFLAG(Slab, slab) +PAGEFLAG(Checked, owner_priv_1) /* Used by some filesystems */ +PAGEFLAG(Pinned, owner_priv_1) TESTSCFLAG(Pinned, owner_priv_1) /* Xen */ +PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved) +PAGEFLAG(Private, private) __CLEARPAGEFLAG(Private, private) + __SETPAGEFLAG(Private, private) -#if (BITS_PER_LONG > 32) /* - * 64-bit-only flags build down from bit 31 - * - * 32 bit -------------------------------| FIELDS | FLAGS | - * 64 bit | FIELDS | ?????? FLAGS | - * 63 32 0 + * Only test-and-set exist for PG_writeback. The unconditional operators are + * risky: they bypass page accounting. */ -#define PG_uncached 31 /* Page has been mapped as uncached */ -#endif +TESTPAGEFLAG(Writeback, writeback) TESTSCFLAG(Writeback, writeback) +__PAGEFLAG(Buddy, buddy) +PAGEFLAG(MappedToDisk, mappedtodisk) +/* PG_readahead is only used for file reads; PG_reclaim is only for writes */ +PAGEFLAG(Reclaim, reclaim) TESTCLEARFLAG(Reclaim, reclaim) +PAGEFLAG(Readahead, reclaim) /* Reminder to do async read-ahead */ + +#ifdef CONFIG_HIGHMEM /* - * Manipulation of page state flags + * Must use a macro here due to header dependency issues. page_zone() is not + * available at this point. */ -#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 PageHighMem(__p) is_highmem(page_zone(__p)) +#else +PAGEFLAG_FALSE(HighMem) +#endif + +#ifdef CONFIG_SWAP +PAGEFLAG(SwapCache, swapcache) +#else +PAGEFLAG_FALSE(SwapCache) +#endif + +#ifdef CONFIG_IA64_UNCACHED_ALLOCATOR +PAGEFLAG(Uncached, uncached) +#else +PAGEFLAG_FALSE(Uncached) +#endif static inline int PageUptodate(struct page *page) { @@ -177,97 +241,59 @@ static inline void SetPageUptodate(struct page *page) #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 PageLRU(page) test_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 __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) - -#ifdef CONFIG_HIGHMEM -#define PageHighMem(page) is_highmem(page_zone(page)) -#else -#define PageHighMem(page) 0 /* needed to optimize away at compile time */ -#endif +CLEARPAGEFLAG(Uptodate, uptodate) -#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 PagePinned(page) test_bit(PG_pinned, &(page)->flags) -#define SetPagePinned(page) set_bit(PG_pinned, &(page)->flags) -#define ClearPagePinned(page) clear_bit(PG_pinned, &(page)->flags) +extern void cancel_dirty_page(struct page *page, unsigned int account_size); -#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) +int test_clear_page_writeback(struct page *page); +int test_set_page_writeback(struct page *page); -#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) +static inline void set_page_writeback(struct page *page) +{ + test_set_page_writeback(page); +} +#ifdef CONFIG_PAGEFLAGS_EXTENDED /* - * Only test-and-set exist for PG_writeback. The unconditional operators are - * risky: they bypass page accounting. + * System with lots of page flags available. This allows separate + * flags for PageHead() and PageTail() checks of compound pages so that bit + * tests can be used in performance sensitive paths. PageCompound is + * generally not used in hot code paths. */ -#define PageWriteback(page) test_bit(PG_writeback, &(page)->flags) -#define TestSetPageWriteback(page) test_and_set_bit(PG_writeback, \ - &(page)->flags) -#define TestClearPageWriteback(page) test_and_clear_bit(PG_writeback, \ - &(page)->flags) +__PAGEFLAG(Head, head) +__PAGEFLAG(Tail, tail) -#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 PageReadahead(page) test_bit(PG_readahead, &(page)->flags) -#define SetPageReadahead(page) set_bit(PG_readahead, &(page)->flags) -#define ClearPageReadahead(page) clear_bit(PG_readahead, &(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) +static inline int PageCompound(struct page *page) +{ + return page->flags & ((1L << PG_head) | (1L << PG_tail)); -#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) +} +#else +/* + * Reduce page flag use as much as possible by overlapping + * compound page flags with the flags used for page cache pages. Possible + * because PageCompound is always set for compound pages and not for + * pages on the LRU and/or pagecache. + */ +TESTPAGEFLAG(Compound, compound) +__PAGEFLAG(Head, compound) /* * PG_reclaim is used in combination with PG_compound to mark the - * head and tail of a compound page + * head and tail of a compound page. This saves one page flag + * but makes it impossible to use compound pages for the page cache. + * The PG_reclaim bit would have to be used for reclaim or readahead + * if compound pages enter the page cache. * * PG_compound & PG_reclaim => Tail page * PG_compound & ~PG_reclaim => Head page */ - #define PG_head_tail_mask ((1L << PG_compound) | (1L << PG_reclaim)) -#define PageTail(page) (((page)->flags & PG_head_tail_mask) \ - == PG_head_tail_mask) +static inline int PageTail(struct page *page) +{ + return ((page->flags & PG_head_tail_mask) == PG_head_tail_mask); +} static inline void __SetPageTail(struct page *page) { @@ -279,33 +305,6 @@ static inline void __ClearPageTail(struct page *page) page->flags &= ~PG_head_tail_mask; } -#define PageHead(page) (((page)->flags & PG_head_tail_mask) \ - == (1L << PG_compound)) -#define __SetPageHead(page) __SetPageCompound(page) -#define __ClearPageHead(page) __ClearPageCompound(page) - -#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 */ - -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 set_page_writeback(struct page *page) -{ - test_set_page_writeback(page); -} - +#endif /* !PAGEFLAGS_EXTENDED */ +#endif /* !__GENERATING_BOUNDS_H */ #endif /* PAGE_FLAGS_H */ |