diff options
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 286 |
1 files changed, 173 insertions, 113 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index bb53c7b86315..19724e6ebd26 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -101,9 +101,6 @@ enum pageflags { #ifdef CONFIG_MEMORY_FAILURE PG_hwpoison, /* hardware poisoned page. Don't touch */ #endif -#ifdef CONFIG_TRANSPARENT_HUGEPAGE - PG_compound_lock, -#endif #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) PG_young, PG_idle, @@ -129,53 +126,104 @@ enum pageflags { /* SLOB */ PG_slob_free = PG_private, + + /* Compound pages. Stored in first tail page's flags */ + PG_double_map = PG_private_2, }; #ifndef __GENERATING_BOUNDS_H +struct page; /* forward declaration */ + +static inline struct page *compound_head(struct page *page) +{ + unsigned long head = READ_ONCE(page->compound_head); + + if (unlikely(head & 1)) + return (struct page *) (head - 1); + return page; +} + +static inline int PageTail(struct page *page) +{ + return READ_ONCE(page->compound_head) & 1; +} + +static inline int PageCompound(struct page *page) +{ + return test_bit(PG_head, &page->flags) || PageTail(page); +} + +/* + * Page flags policies wrt compound pages + * + * PF_ANY: + * the page flag is relevant for small, head and tail pages. + * + * PF_HEAD: + * for compound page all operations related to the page flag applied to + * head page. + * + * PF_NO_TAIL: + * modifications of the page flag must be done on small or head pages, + * checks can be done on tail pages too. + * + * PF_NO_COMPOUND: + * the page flag is not relevant for compound pages. + */ +#define PF_ANY(page, enforce) page +#define PF_HEAD(page, enforce) compound_head(page) +#define PF_NO_TAIL(page, enforce) ({ \ + VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ + compound_head(page);}) +#define PF_NO_COMPOUND(page, enforce) ({ \ + VM_BUG_ON_PGFLAGS(enforce && PageCompound(page), page); \ + page;}) + /* * Macros to create function definitions for page flags */ -#define TESTPAGEFLAG(uname, lname) \ -static inline int Page##uname(const struct page *page) \ - { return test_bit(PG_##lname, &page->flags); } +#define TESTPAGEFLAG(uname, lname, policy) \ +static inline int Page##uname(struct page *page) \ + { return test_bit(PG_##lname, &policy(page, 0)->flags); } -#define SETPAGEFLAG(uname, lname) \ +#define SETPAGEFLAG(uname, lname, policy) \ static inline void SetPage##uname(struct page *page) \ - { set_bit(PG_##lname, &page->flags); } + { set_bit(PG_##lname, &policy(page, 1)->flags); } -#define CLEARPAGEFLAG(uname, lname) \ +#define CLEARPAGEFLAG(uname, lname, policy) \ static inline void ClearPage##uname(struct page *page) \ - { clear_bit(PG_##lname, &page->flags); } + { clear_bit(PG_##lname, &policy(page, 1)->flags); } -#define __SETPAGEFLAG(uname, lname) \ +#define __SETPAGEFLAG(uname, lname, policy) \ static inline void __SetPage##uname(struct page *page) \ - { __set_bit(PG_##lname, &page->flags); } + { __set_bit(PG_##lname, &policy(page, 1)->flags); } -#define __CLEARPAGEFLAG(uname, lname) \ +#define __CLEARPAGEFLAG(uname, lname, policy) \ static inline void __ClearPage##uname(struct page *page) \ - { __clear_bit(PG_##lname, &page->flags); } + { __clear_bit(PG_##lname, &policy(page, 1)->flags); } -#define TESTSETFLAG(uname, lname) \ +#define TESTSETFLAG(uname, lname, policy) \ static inline int TestSetPage##uname(struct page *page) \ - { return test_and_set_bit(PG_##lname, &page->flags); } + { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } -#define TESTCLEARFLAG(uname, lname) \ +#define TESTCLEARFLAG(uname, lname, policy) \ 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); } + { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } -#define PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \ - SETPAGEFLAG(uname, lname) CLEARPAGEFLAG(uname, lname) +#define PAGEFLAG(uname, lname, policy) \ + TESTPAGEFLAG(uname, lname, policy) \ + SETPAGEFLAG(uname, lname, policy) \ + CLEARPAGEFLAG(uname, lname, policy) -#define __PAGEFLAG(uname, lname) TESTPAGEFLAG(uname, lname) \ - __SETPAGEFLAG(uname, lname) __CLEARPAGEFLAG(uname, lname) +#define __PAGEFLAG(uname, lname, policy) \ + TESTPAGEFLAG(uname, lname, policy) \ + __SETPAGEFLAG(uname, lname, policy) \ + __CLEARPAGEFLAG(uname, lname, policy) -#define TESTSCFLAG(uname, lname) \ - TESTSETFLAG(uname, lname) TESTCLEARFLAG(uname, lname) +#define TESTSCFLAG(uname, lname, policy) \ + TESTSETFLAG(uname, lname, policy) \ + TESTCLEARFLAG(uname, lname, policy) #define TESTPAGEFLAG_FALSE(uname) \ static inline int Page##uname(const struct page *page) { return 0; } @@ -195,56 +243,62 @@ static inline int TestSetPage##uname(struct page *page) { return 0; } #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; } - #define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \ SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname) #define TESTSCFLAG_FALSE(uname) \ TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) -struct page; /* forward declaration */ - -TESTPAGEFLAG(Locked, locked) -PAGEFLAG(Error, error) TESTCLEARFLAG(Error, error) -PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced) - __SETPAGEFLAG(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(Foreign, foreign); /* Xen */ -PAGEFLAG(Reserved, reserved) __CLEARPAGEFLAG(Reserved, reserved) -PAGEFLAG(SwapBacked, swapbacked) __CLEARPAGEFLAG(SwapBacked, swapbacked) - __SETPAGEFLAG(SwapBacked, swapbacked) - -__PAGEFLAG(SlobFree, slob_free) +__PAGEFLAG(Locked, locked, PF_NO_TAIL) +PAGEFLAG(Error, error, PF_NO_COMPOUND) TESTCLEARFLAG(Error, error, PF_NO_COMPOUND) +PAGEFLAG(Referenced, referenced, PF_HEAD) + TESTCLEARFLAG(Referenced, referenced, PF_HEAD) + __SETPAGEFLAG(Referenced, referenced, PF_HEAD) +PAGEFLAG(Dirty, dirty, PF_HEAD) TESTSCFLAG(Dirty, dirty, PF_HEAD) + __CLEARPAGEFLAG(Dirty, dirty, PF_HEAD) +PAGEFLAG(LRU, lru, PF_HEAD) __CLEARPAGEFLAG(LRU, lru, PF_HEAD) +PAGEFLAG(Active, active, PF_HEAD) __CLEARPAGEFLAG(Active, active, PF_HEAD) + TESTCLEARFLAG(Active, active, PF_HEAD) +__PAGEFLAG(Slab, slab, PF_NO_TAIL) +__PAGEFLAG(SlobFree, slob_free, PF_NO_TAIL) +PAGEFLAG(Checked, checked, PF_NO_COMPOUND) /* Used by some filesystems */ + +/* Xen */ +PAGEFLAG(Pinned, pinned, PF_NO_COMPOUND) + TESTSCFLAG(Pinned, pinned, PF_NO_COMPOUND) +PAGEFLAG(SavePinned, savepinned, PF_NO_COMPOUND); +PAGEFLAG(Foreign, foreign, PF_NO_COMPOUND); + +PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) + __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) +PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) + __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) + __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) /* * 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 */ -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) +PAGEFLAG(Private, private, PF_ANY) __SETPAGEFLAG(Private, private, PF_ANY) + __CLEARPAGEFLAG(Private, private, PF_ANY) +PAGEFLAG(Private2, private_2, PF_ANY) TESTSCFLAG(Private2, private_2, PF_ANY) +PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY) + TESTCLEARFLAG(OwnerPriv1, owner_priv_1, PF_ANY) /* * Only test-and-set exist for PG_writeback. The unconditional operators are * risky: they bypass page accounting. */ -TESTPAGEFLAG(Writeback, writeback) TESTSCFLAG(Writeback, writeback) -PAGEFLAG(MappedToDisk, mappedtodisk) +TESTPAGEFLAG(Writeback, writeback, PF_NO_COMPOUND) + TESTSCFLAG(Writeback, writeback, PF_NO_COMPOUND) +PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_COMPOUND) /* PG_readahead is only used for reads; PG_reclaim is only for writes */ -PAGEFLAG(Reclaim, reclaim) TESTCLEARFLAG(Reclaim, reclaim) -PAGEFLAG(Readahead, reclaim) TESTCLEARFLAG(Readahead, reclaim) +PAGEFLAG(Reclaim, reclaim, PF_NO_COMPOUND) + TESTCLEARFLAG(Reclaim, reclaim, PF_NO_COMPOUND) +PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND) + TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND) #ifdef CONFIG_HIGHMEM /* @@ -257,31 +311,33 @@ PAGEFLAG_FALSE(HighMem) #endif #ifdef CONFIG_SWAP -PAGEFLAG(SwapCache, swapcache) +PAGEFLAG(SwapCache, swapcache, PF_NO_COMPOUND) #else PAGEFLAG_FALSE(SwapCache) #endif -PAGEFLAG(Unevictable, unevictable) __CLEARPAGEFLAG(Unevictable, unevictable) - TESTCLEARFLAG(Unevictable, unevictable) +PAGEFLAG(Unevictable, unevictable, PF_HEAD) + __CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD) + TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD) #ifdef CONFIG_MMU -PAGEFLAG(Mlocked, mlocked) __CLEARPAGEFLAG(Mlocked, mlocked) - TESTSCFLAG(Mlocked, mlocked) __TESTCLEARFLAG(Mlocked, mlocked) +PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) + __CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) + TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL) #else PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked) - TESTSCFLAG_FALSE(Mlocked) __TESTCLEARFLAG_FALSE(Mlocked) + TESTSCFLAG_FALSE(Mlocked) #endif #ifdef CONFIG_ARCH_USES_PG_UNCACHED -PAGEFLAG(Uncached, uncached) +PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND) #else PAGEFLAG_FALSE(Uncached) #endif #ifdef CONFIG_MEMORY_FAILURE -PAGEFLAG(HWPoison, hwpoison) -TESTSCFLAG(HWPoison, hwpoison) +PAGEFLAG(HWPoison, hwpoison, PF_ANY) +TESTSCFLAG(HWPoison, hwpoison, PF_ANY) #define __PG_HWPOISON (1UL << PG_hwpoison) #else PAGEFLAG_FALSE(HWPoison) @@ -289,10 +345,10 @@ PAGEFLAG_FALSE(HWPoison) #endif #if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) -TESTPAGEFLAG(Young, young) -SETPAGEFLAG(Young, young) -TESTCLEARFLAG(Young, young) -PAGEFLAG(Idle, idle) +TESTPAGEFLAG(Young, young, PF_ANY) +SETPAGEFLAG(Young, young, PF_ANY) +TESTCLEARFLAG(Young, young, PF_ANY) +PAGEFLAG(Idle, idle, PF_ANY) #endif /* @@ -317,6 +373,7 @@ PAGEFLAG(Idle, idle) static inline int PageAnon(struct page *page) { + page = compound_head(page); return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; } @@ -329,6 +386,7 @@ static inline int PageAnon(struct page *page) */ static inline int PageKsm(struct page *page) { + page = compound_head(page); return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == (PAGE_MAPPING_ANON | PAGE_MAPPING_KSM); } @@ -340,8 +398,9 @@ u64 stable_page_flags(struct page *page); static inline int PageUptodate(struct page *page) { - int ret = test_bit(PG_uptodate, &(page)->flags); - + int ret; + page = compound_head(page); + 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. @@ -358,22 +417,24 @@ static inline int PageUptodate(struct page *page) static inline void __SetPageUptodate(struct page *page) { + VM_BUG_ON_PAGE(PageTail(page), page); smp_wmb(); - __set_bit(PG_uptodate, &(page)->flags); + __set_bit(PG_uptodate, &page->flags); } static inline void SetPageUptodate(struct page *page) { + VM_BUG_ON_PAGE(PageTail(page), page); /* * 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. */ smp_wmb(); - set_bit(PG_uptodate, &(page)->flags); + set_bit(PG_uptodate, &page->flags); } -CLEARPAGEFLAG(Uptodate, uptodate) +CLEARPAGEFLAG(Uptodate, uptodate, PF_NO_TAIL) int test_clear_page_writeback(struct page *page); int __test_set_page_writeback(struct page *page, bool keep_write); @@ -393,12 +454,7 @@ static inline void set_page_writeback_keepwrite(struct page *page) test_set_page_writeback_keepwrite(page); } -__PAGEFLAG(Head, head) CLEARPAGEFLAG(Head, head) - -static inline int PageTail(struct page *page) -{ - return READ_ONCE(page->compound_head) & 1; -} +__PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY) static inline void set_compound_head(struct page *page, struct page *head) { @@ -410,20 +466,6 @@ static inline void clear_compound_head(struct page *page) WRITE_ONCE(page->compound_head, 0); } -static inline struct page *compound_head(struct page *page) -{ - unsigned long head = READ_ONCE(page->compound_head); - - if (unlikely(head & 1)) - return (struct page *) (head - 1); - return page; -} - -static inline int PageCompound(struct page *page) -{ - return PageHead(page) || PageTail(page); - -} #ifdef CONFIG_TRANSPARENT_HUGEPAGE static inline void ClearPageCompound(struct page *page) { @@ -484,22 +526,43 @@ static inline int PageTransTail(struct page *page) return PageTail(page); } -#else - -static inline int PageTransHuge(struct page *page) +/* + * PageDoubleMap indicates that the compound page is mapped with PTEs as well + * as PMDs. + * + * This is required for optimization of rmap operations for THP: we can postpone + * per small page mapcount accounting (and its overhead from atomic operations) + * until the first PMD split. + * + * For the page PageDoubleMap means ->_mapcount in all sub-pages is offset up + * by one. This reference will go away with last compound_mapcount. + * + * See also __split_huge_pmd_locked() and page_remove_anon_compound_rmap(). + */ +static inline int PageDoubleMap(struct page *page) { - return 0; + return PageHead(page) && test_bit(PG_double_map, &page[1].flags); } -static inline int PageTransCompound(struct page *page) +static inline int TestSetPageDoubleMap(struct page *page) { - return 0; + VM_BUG_ON_PAGE(!PageHead(page), page); + return test_and_set_bit(PG_double_map, &page[1].flags); } -static inline int PageTransTail(struct page *page) +static inline int TestClearPageDoubleMap(struct page *page) { - return 0; + VM_BUG_ON_PAGE(!PageHead(page), page); + return test_and_clear_bit(PG_double_map, &page[1].flags); } + +#else +TESTPAGEFLAG_FALSE(TransHuge) +TESTPAGEFLAG_FALSE(TransCompound) +TESTPAGEFLAG_FALSE(TransTail) +TESTPAGEFLAG_FALSE(DoubleMap) + TESTSETFLAG_FALSE(DoubleMap) + TESTCLEARFLAG_FALSE(DoubleMap) #endif /* @@ -583,12 +646,6 @@ static inline void ClearPageSlabPfmemalloc(struct page *page) #define __PG_MLOCKED 0 #endif -#ifdef CONFIG_TRANSPARENT_HUGEPAGE -#define __PG_COMPOUND_LOCK (1 << PG_compound_lock) -#else -#define __PG_COMPOUND_LOCK 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. @@ -598,8 +655,7 @@ static inline void ClearPageSlabPfmemalloc(struct page *page) 1 << PG_private | 1 << PG_private_2 | \ 1 << PG_writeback | 1 << PG_reserved | \ 1 << PG_slab | 1 << PG_swapcache | 1 << PG_active | \ - 1 << PG_unevictable | __PG_MLOCKED | \ - __PG_COMPOUND_LOCK) + 1 << PG_unevictable | __PG_MLOCKED) /* * Flags checked when a page is prepped for return by the page allocator. @@ -626,6 +682,10 @@ static inline int page_has_private(struct page *page) return !!(page->flags & PAGE_FLAGS_PRIVATE); } +#undef PF_ANY +#undef PF_HEAD +#undef PF_NO_TAIL +#undef PF_NO_COMPOUND #endif /* !__GENERATING_BOUNDS_H */ #endif /* PAGE_FLAGS_H */ |