X-Git-Url: http://ftp.safe.ca/?a=blobdiff_plain;f=include%2Flinux%2Fpage-flags.h;h=5b59f35dcb8fdd3ef12c4bc4f2cd5f439e63053b;hb=6c1f716e8154ee9315534782b9b1eedea0559a24;hp=350878a2d848cf2efe561449ac7d9ccece15630b;hpb=fba2591bf4e418b6c3f9f8794c9dd8fe40ae7bd9;p=safe%2Fjmp%2Flinux-2.6 diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 350878a..5b59f35 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -6,6 +6,10 @@ #define PAGE_FLAGS_H #include +#ifndef __GENERATING_BOUNDS_H +#include +#include +#endif /* !__GENERATING_BOUNDS_H */ /* * Various page->flags bits: @@ -47,6 +51,9 @@ * PG_buddy is set to indicate that the page is free and in the buddy system * (see mm/page_alloc.c). * + * PG_hwpoison indicates that a page got corrupted in hardware and contains + * data with incorrect ECC bits that triggered a machine check. Accessing is + * not safe since it may cause another machine check. Don't touch! */ /* @@ -58,200 +65,269 @@ * 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_private_2, /* If pagecache, has fs aux 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 */ + PG_swapbacked, /* Page is backed by RAM/swap */ + PG_unevictable, /* Page is "unevictable" */ +#ifdef CONFIG_MMU + PG_mlocked, /* Page is vma mlocked */ +#endif +#ifdef CONFIG_ARCH_USES_PG_UNCACHED + PG_uncached, /* Page has been mapped as uncached */ +#endif +#ifdef CONFIG_MEMORY_FAILURE + PG_hwpoison, /* hardware poisoned page. Don't touch */ +#endif + __NR_PAGEFLAGS, + + /* Filesystems */ + PG_checked = PG_owner_priv_1, -#define PG_dirty 4 -#define PG_lru 5 -#define PG_active 6 -#define PG_slab 7 /* slab debug (Suparna wants this) */ + /* Two page bits are conscripted by FS-Cache to maintain local caching + * state. These bits are set on pages belonging to the netfs's inodes + * when those inodes are being locally cached. + */ + PG_fscache = PG_private_2, /* page backed by cache */ -#define PG_checked 8 /* kill me in 2.5.. */ -#define PG_arch_1 9 -#define PG_reserved 10 -#define PG_private 11 /* If pagecache, has fs-private data */ + /* XEN */ + PG_pinned = PG_owner_priv_1, + PG_savepinned = PG_dirty, -#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 */ + /* SLOB */ + PG_slob_free = PG_private, -#define PG_mappedtodisk 16 /* Has blocks allocated on-disk */ -#define PG_reclaim 17 /* To be reclaimed asap */ -#define PG_nosave_free 18 /* Used for system suspend/resume */ -#define PG_buddy 19 /* Page is free, on buddy lists */ + /* SLUB */ + PG_slub_frozen = PG_active, + PG_slub_debug = PG_error, +}; +#ifndef __GENERATING_BOUNDS_H -#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 + * Macros to create function definitions for page flags */ -#define PG_uncached 31 /* Page has been mapped as uncached */ -#endif +#define TESTPAGEFLAG(uname, lname) \ +static inline int Page##uname(struct page *page) \ + { return test_bit(PG_##lname, &page->flags); } + +#define SETPAGEFLAG(uname, lname) \ +static inline void SetPage##uname(struct page *page) \ + { set_bit(PG_##lname, &page->flags); } + +#define CLEARPAGEFLAG(uname, lname) \ +static inline void ClearPage##uname(struct page *page) \ + { clear_bit(PG_##lname, &page->flags); } + +#define __SETPAGEFLAG(uname, lname) \ +static inline void __SetPage##uname(struct page *page) \ + { __set_bit(PG_##lname, &page->flags); } + +#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); } + +#define __TESTCLEARFLAG(uname, lname) \ +static inline int __TestClearPage##uname(struct page *page) \ + { return __test_and_clear_bit(PG_##lname, &page->flags); } + +#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) + +#define SETPAGEFLAG_NOOP(uname) \ +static inline void SetPage##uname(struct page *page) { } + +#define CLEARPAGEFLAG_NOOP(uname) \ +static inline void ClearPage##uname(struct page *page) { } + +#define __CLEARPAGEFLAG_NOOP(uname) \ +static inline void __ClearPage##uname(struct page *page) { } + +#define TESTCLEARFLAG_FALSE(uname) \ +static inline int TestClearPage##uname(struct page *page) { return 0; } + +#define __TESTCLEARFLAG_FALSE(uname) \ +static inline int __TestClearPage##uname(struct page *page) { return 0; } + +struct page; /* forward declaration */ + +TESTPAGEFLAG(Locked, locked) TESTSETFLAG(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) + TESTCLEARFLAG(Active, active) +__PAGEFLAG(Slab, slab) +PAGEFLAG(Checked, checked) /* Used by some filesystems */ +PAGEFLAG(Pinned, pinned) TESTSCFLAG(Pinned, pinned) /* Xen */ +PAGEFLAG(SavePinned, savepinned); /* Xen */ +PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved) +PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked) + +__PAGEFLAG(SlobFree, slob_free) + +__PAGEFLAG(SlubFrozen, slub_frozen) +__PAGEFLAG(SlubDebug, slub_debug) /* - * Manipulation of page state flags + * Private page markings that may be used by the filesystem that owns the page + * for its own purposes. + * - PG_private and PG_private_2 cause releasepage() and co to be invoked */ -#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) -#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); -} +PAGEFLAG(Private, private) __SETPAGEFLAG(Private, private) + __CLEARPAGEFLAG(Private, private) +PAGEFLAG(Private2, private_2) TESTSCFLAG(Private2, private_2) +PAGEFLAG(OwnerPriv1, owner_priv_1) TESTCLEARFLAG(OwnerPriv1, owner_priv_1) + +/* + * Only test-and-set exist for PG_writeback. The unconditional operators are + * risky: they bypass page accounting. + */ +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 +/* + * Must use a macro here due to header dependency issues. page_zone() is not + * available at this point. + */ +#define PageHighMem(__p) is_highmem(page_zone(__p)) #else -#define SetPageUptodate(page) set_bit(PG_uptodate, &(page)->flags) +PAGEFLAG_FALSE(HighMem) #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) +#ifdef CONFIG_SWAP +PAGEFLAG(SwapCache, swapcache) +#else +PAGEFLAG_FALSE(SwapCache) + SETPAGEFLAG_NOOP(SwapCache) CLEARPAGEFLAG_NOOP(SwapCache) +#endif -#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) +PAGEFLAG(Unevictable, unevictable) __CLEARPAGEFLAG(Unevictable, unevictable) + TESTCLEARFLAG(Unevictable, unevictable) -#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) +#ifdef CONFIG_MMU +PAGEFLAG(Mlocked, mlocked) __CLEARPAGEFLAG(Mlocked, mlocked) + TESTSCFLAG(Mlocked, mlocked) __TESTCLEARFLAG(Mlocked, mlocked) +#else +PAGEFLAG_FALSE(Mlocked) SETPAGEFLAG_NOOP(Mlocked) + TESTCLEARFLAG_FALSE(Mlocked) __TESTCLEARFLAG_FALSE(Mlocked) +#endif -#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_ARCH_USES_PG_UNCACHED +PAGEFLAG(Uncached, uncached) +#else +PAGEFLAG_FALSE(Uncached) +#endif -#ifdef CONFIG_HIGHMEM -#define PageHighMem(page) is_highmem(page_zone(page)) +#ifdef CONFIG_MEMORY_FAILURE +PAGEFLAG(HWPoison, hwpoison) +TESTSCFLAG(HWPoison, hwpoison) +#define __PG_HWPOISON (1UL << PG_hwpoison) #else -#define PageHighMem(page) 0 /* needed to optimize away at compile time */ +PAGEFLAG_FALSE(HWPoison) +#define __PG_HWPOISON 0 #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_zone_page_state(page, NR_WRITEBACK); \ - } while (0) -#define TestSetPageWriteback(page) \ - ({ \ - int ret; \ - ret = test_and_set_bit(PG_writeback, \ - &(page)->flags); \ - if (!ret) \ - inc_zone_page_state(page, NR_WRITEBACK); \ - ret; \ - }) -#define ClearPageWriteback(page) \ - do { \ - if (test_and_clear_bit(PG_writeback, \ - &(page)->flags)) \ - dec_zone_page_state(page, NR_WRITEBACK); \ - } while (0) -#define TestClearPageWriteback(page) \ - ({ \ - int ret; \ - ret = test_and_clear_bit(PG_writeback, \ - &(page)->flags); \ - if (ret) \ - dec_zone_page_state(page, 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 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 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) - -#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) +u64 stable_page_flags(struct page *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) +static inline int PageUptodate(struct page *page) +{ + int ret = test_bit(PG_uptodate, &(page)->flags); + + /* + * Must ensure that the data we read out of the page is loaded + * _after_ we've loaded page->flags to check for PageUptodate. + * We can skip the barrier if the page is not uptodate, because + * we wouldn't be reading anything from it. + * + * See SetPageUptodate() for the other side of the story. + */ + if (ret) + smp_rmb(); + + return ret; +} + +static inline void __SetPageUptodate(struct page *page) +{ + smp_wmb(); + __set_bit(PG_uptodate, &(page)->flags); +} + +static inline void SetPageUptodate(struct page *page) +{ +#ifdef CONFIG_S390 + if (!test_and_set_bit(PG_uptodate, &page->flags)) + page_clear_dirty(page); #else -#define PageSwapCache(page) 0 + /* + * Memory barrier must be issued before setting the PG_uptodate bit, + * so that all previous stores issued in order to bring the page + * uptodate are actually visible before PageUptodate becomes true. + * + * s390 doesn't need an explicit smp_wmb here because the test and + * set bit already provides full barriers. + */ + smp_wmb(); + set_bit(PG_uptodate, &(page)->flags); #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 */ +CLEARPAGEFLAG(Uptodate, uptodate) extern void cancel_dirty_page(struct page *page, unsigned int account_size); @@ -263,4 +339,98 @@ static inline void set_page_writeback(struct page *page) test_set_page_writeback(page); } +#ifdef CONFIG_PAGEFLAGS_EXTENDED +/* + * 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. + */ +__PAGEFLAG(Head, head) +__PAGEFLAG(Tail, tail) + +static inline int PageCompound(struct page *page) +{ + return page->flags & ((1L << PG_head) | (1L << PG_tail)); + +} +#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. 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)) + +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) +{ + page->flags |= PG_head_tail_mask; +} + +static inline void __ClearPageTail(struct page *page) +{ + page->flags &= ~PG_head_tail_mask; +} + +#endif /* !PAGEFLAGS_EXTENDED */ + +#ifdef CONFIG_MMU +#define __PG_MLOCKED (1 << PG_mlocked) +#else +#define __PG_MLOCKED 0 +#endif + +/* + * Flags checked when a page is freed. Pages being freed should not have + * these flags set. It they are, there is a problem. + */ +#define PAGE_FLAGS_CHECK_AT_FREE \ + (1 << PG_lru | 1 << PG_locked | \ + 1 << PG_private | 1 << PG_private_2 | \ + 1 << PG_buddy | 1 << PG_writeback | 1 << PG_reserved | \ + 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \ + 1 << PG_unevictable | __PG_MLOCKED | __PG_HWPOISON) + +/* + * Flags checked when a page is prepped for return by the page allocator. + * Pages being prepped should not have any flags set. It they are set, + * there has been a kernel bug or struct page corruption. + */ +#define PAGE_FLAGS_CHECK_AT_PREP ((1 << NR_PAGEFLAGS) - 1) + +#define PAGE_FLAGS_PRIVATE \ + (1 << PG_private | 1 << PG_private_2) +/** + * page_has_private - Determine if page has private stuff + * @page: The page to be checked + * + * Determine if a page has private stuff, indicating that release routines + * should be invoked upon it. + */ +static inline int page_has_private(struct page *page) +{ + return !!(page->flags & PAGE_FLAGS_PRIVATE); +} + +#endif /* !__GENERATING_BOUNDS_H */ + #endif /* PAGE_FLAGS_H */