diff options
Diffstat (limited to 'include/linux/page-flags.h')
| -rw-r--r-- | include/linux/page-flags.h | 1005 |
1 files changed, 684 insertions, 321 deletions
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h index 4f6ba9379112..4fe5ee67535b 100644 --- a/include/linux/page-flags.h +++ b/include/linux/page-flags.h @@ -30,16 +30,11 @@ * - Pages falling into physical memory gaps - not IORESOURCE_SYSRAM. Trying * to read/write these pages might end badly. Don't touch! * - The zero page(s) - * - Pages not added to the page allocator when onlining a section because - * they were excluded via the online_page_callback() or because they are - * PG_hwpoison. * - Pages allocated in the context of kexec/kdump (loaded kernel image, * control pages, vmcoreinfo) * - MMIO/DMA pages. Some architectures don't allow to ioremap pages that are * not marked PG_reserved (as they might be in use by somebody else who does * not respect the caching strategy). - * - Pages part of an offline section (struct pages of offline sections should - * not be trusted as they will be initialized when first onlined). * - MCA pages on ia64 * - Pages holding CPU notes for POWER Firmware Assisted Dump * - Device memory (e.g. PMEM, DAX, HMM) @@ -68,14 +63,9 @@ * might lose their PG_swapbacked flag when they simply can be dropped (e.g. as * a result of MADV_FREE). * - * 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. - * * 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. - * * PG_arch_1 is an architecture specific page state bit. The generic code * guarantees that this bit is cleared for a page when it first is entered into * the page cache. @@ -86,8 +76,7 @@ */ /* - * Don't use the *_dontuse flags. Use the macros. Otherwise you'll break - * locked- and dirty-page accounting. + * Don't use the pageflags directly. Use the PageFoo macros. * * 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 @@ -103,49 +92,64 @@ */ enum pageflags { PG_locked, /* Page is locked. Don't touch. */ + PG_writeback, /* Page is under writeback */ PG_referenced, PG_uptodate, PG_dirty, PG_lru, + PG_head, /* Must be in bit 6 */ + PG_waiters, /* Page has waiters, check its waitqueue. Must be bit #7 and in the same byte as "PG_locked" */ PG_active, PG_workingset, - PG_waiters, /* Page has waiters, check its waitqueue. Must be bit #7 and in the same byte as "PG_locked" */ - PG_error, - PG_slab, - PG_owner_priv_1, /* Owner use. If pagecache, fs may use*/ + PG_owner_priv_1, /* Owner use. If pagecache, fs may use */ + PG_owner_2, /* 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 */ - PG_head, /* A head page */ - PG_mappedtodisk, /* Has blocks allocated on-disk */ PG_reclaim, /* To be reclaimed asap */ PG_swapbacked, /* Page is backed by RAM/swap */ PG_unevictable, /* Page is "unevictable" */ + PG_dropbehind, /* drop pages on IO completion */ #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 -#if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) +#if defined(CONFIG_PAGE_IDLE_FLAG) && defined(CONFIG_64BIT) PG_young, PG_idle, #endif -#ifdef CONFIG_64BIT +#ifdef CONFIG_ARCH_USES_PG_ARCH_2 PG_arch_2, #endif +#ifdef CONFIG_ARCH_USES_PG_ARCH_3 + PG_arch_3, +#endif __NR_PAGEFLAGS, - /* Filesystems */ + PG_readahead = PG_reclaim, + + /* Anonymous memory (and shmem) */ + PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */ + /* Some filesystems */ PG_checked = PG_owner_priv_1, - /* SwapBacked */ - PG_swapcache = PG_owner_priv_1, /* Swap page: swp_entry_t in private */ + /* + * Depending on the way an anonymous folio can be mapped into a page + * table (e.g., single PMD/PUD/CONT of the head page vs. PTE-mapped + * THP), PG_anon_exclusive may be set only for the head page or for + * tail pages of an anonymous folio. For now, we only expect it to be + * set on tail pages for PTE-mapped THP. + */ + PG_anon_exclusive = PG_owner_2, + + /* + * Set if all buffer heads in the folio are mapped. + * Filesystems which do not use BHs can use it for their own purpose. + */ + PG_mappedtodisk = PG_owner_2, /* 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 @@ -163,46 +167,168 @@ enum pageflags { /* Remapped by swiotlb-xen. */ PG_xen_remapped = PG_owner_priv_1, - /* SLOB */ - PG_slob_free = PG_private, - - /* Compound pages. Stored in first tail page's flags */ - PG_double_map = PG_workingset, - /* non-lru isolated movable page */ PG_isolated = PG_reclaim, /* Only valid for buddy pages. Used to track pages that are reported */ PG_reported = PG_uptodate, + +#ifdef CONFIG_MEMORY_HOTPLUG + /* For self-hosted memmap pages */ + PG_vmemmap_self_hosted = PG_owner_priv_1, +#endif + + /* + * Flags only valid for compound pages. Stored in first tail page's + * flags word. Cannot use the first 8 flags or any flag marked as + * PF_ANY. + */ + + /* At least one page in this folio has the hwpoison flag set */ + PG_has_hwpoisoned = PG_active, + PG_large_rmappable = PG_workingset, /* anon or file-backed */ + PG_partially_mapped = PG_reclaim, /* was identified to be partially mapped */ }; +#define PAGEFLAGS_MASK ((1UL << NR_PAGEFLAGS) - 1) + #ifndef __GENERATING_BOUNDS_H -struct page; /* forward declaration */ +#ifdef CONFIG_HUGETLB_PAGE_OPTIMIZE_VMEMMAP +DECLARE_STATIC_KEY_FALSE(hugetlb_optimize_vmemmap_key); -static inline struct page *compound_head(struct page *page) +/* + * Return the real head page struct iff the @page is a fake head page, otherwise + * return the @page itself. See Documentation/mm/vmemmap_dedup.rst. + */ +static __always_inline const struct page *page_fixed_fake_head(const struct page *page) +{ + if (!static_branch_unlikely(&hugetlb_optimize_vmemmap_key)) + return page; + + /* + * Only addresses aligned with PAGE_SIZE of struct page may be fake head + * struct page. The alignment check aims to avoid access the fields ( + * e.g. compound_head) of the @page[1]. It can avoid touch a (possibly) + * cold cacheline in some cases. + */ + if (IS_ALIGNED((unsigned long)page, PAGE_SIZE) && + test_bit(PG_head, &page->flags)) { + /* + * We can safely access the field of the @page[1] with PG_head + * because the @page is a compound page composed with at least + * two contiguous pages. + */ + unsigned long head = READ_ONCE(page[1].compound_head); + + if (likely(head & 1)) + return (const struct page *)(head - 1); + } + return page; +} + +static __always_inline bool page_count_writable(const struct page *page, int u) +{ + if (!static_branch_unlikely(&hugetlb_optimize_vmemmap_key)) + return true; + + /* + * The refcount check is ordered before the fake-head check to prevent + * the following race: + * CPU 1 (HVO) CPU 2 (speculative PFN walker) + * + * page_ref_freeze() + * synchronize_rcu() + * rcu_read_lock() + * page_is_fake_head() is false + * vmemmap_remap_pte() + * XXX: struct page[] becomes r/o + * + * page_ref_unfreeze() + * page_ref_count() is not zero + * + * atomic_add_unless(&page->_refcount) + * XXX: try to modify r/o struct page[] + * + * The refcount check also prevents modification attempts to other (r/o) + * tail pages that are not fake heads. + */ + if (atomic_read_acquire(&page->_refcount) == u) + return false; + + return page_fixed_fake_head(page) == page; +} +#else +static inline const struct page *page_fixed_fake_head(const struct page *page) +{ + return page; +} + +static inline bool page_count_writable(const struct page *page, int u) +{ + return true; +} +#endif + +static __always_inline int page_is_fake_head(const struct page *page) +{ + return page_fixed_fake_head(page) != page; +} + +static __always_inline unsigned long _compound_head(const struct page *page) { unsigned long head = READ_ONCE(page->compound_head); if (unlikely(head & 1)) - return (struct page *) (head - 1); - return page; + return head - 1; + return (unsigned long)page_fixed_fake_head(page); } -static __always_inline int PageTail(struct page *page) +#define compound_head(page) ((typeof(page))_compound_head(page)) + +/** + * page_folio - Converts from page to folio. + * @p: The page. + * + * Every page is part of a folio. This function cannot be called on a + * NULL pointer. + * + * Context: No reference, nor lock is required on @page. If the caller + * does not hold a reference, this call may race with a folio split, so + * it should re-check the folio still contains this page after gaining + * a reference on the folio. + * Return: The folio which contains this page. + */ +#define page_folio(p) (_Generic((p), \ + const struct page *: (const struct folio *)_compound_head(p), \ + struct page *: (struct folio *)_compound_head(p))) + +/** + * folio_page - Return a page from a folio. + * @folio: The folio. + * @n: The page number to return. + * + * @n is relative to the start of the folio. This function does not + * check that the page number lies within @folio; the caller is presumed + * to have a reference to the page. + */ +#define folio_page(folio, n) nth_page(&(folio)->page, n) + +static __always_inline int PageTail(const struct page *page) { - return READ_ONCE(page->compound_head) & 1; + return READ_ONCE(page->compound_head) & 1 || page_is_fake_head(page); } -static __always_inline int PageCompound(struct page *page) +static __always_inline int PageCompound(const struct page *page) { - return test_bit(PG_head, &page->flags) || PageTail(page); + return test_bit(PG_head, &page->flags) || + READ_ONCE(page->compound_head) & 1; } #define PAGE_POISON_PATTERN -1l static inline int PagePoisoned(const struct page *page) { - return page->flags == PAGE_POISON_PATTERN; + return READ_ONCE(page->flags) == PAGE_POISON_PATTERN; } #ifdef CONFIG_DEBUG_VM @@ -213,6 +339,25 @@ static inline void page_init_poison(struct page *page, size_t size) } #endif +static const unsigned long *const_folio_flags(const struct folio *folio, + unsigned n) +{ + const struct page *page = &folio->page; + + VM_BUG_ON_PGFLAGS(page->compound_head & 1, page); + VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page); + return &page[n].flags; +} + +static unsigned long *folio_flags(struct folio *folio, unsigned n) +{ + struct page *page = &folio->page; + + VM_BUG_ON_PGFLAGS(page->compound_head & 1, page); + VM_BUG_ON_PGFLAGS(n > 0 && !test_bit(PG_head, &page->flags), page); + return &page[n].flags; +} + /* * Page flags policies wrt compound pages * @@ -226,9 +371,6 @@ static inline void page_init_poison(struct page *page, size_t size) * for compound page all operations related to the page flag applied to * head page. * - * PF_ONLY_HEAD: - * for compound page, callers only ever operate on the 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. @@ -244,9 +386,6 @@ static inline void page_init_poison(struct page *page, size_t size) page; }) #define PF_ANY(page, enforce) PF_POISONED_CHECK(page) #define PF_HEAD(page, enforce) PF_POISONED_CHECK(compound_head(page)) -#define PF_ONLY_HEAD(page, enforce) ({ \ - VM_BUG_ON_PGFLAGS(PageTail(page), page); \ - PF_POISONED_CHECK(page); }) #define PF_NO_TAIL(page, enforce) ({ \ VM_BUG_ON_PGFLAGS(enforce && PageTail(page), page); \ PF_POISONED_CHECK(compound_head(page)); }) @@ -257,36 +396,86 @@ static inline void page_init_poison(struct page *page, size_t size) VM_BUG_ON_PGFLAGS(!PageHead(page), page); \ PF_POISONED_CHECK(&page[1]); }) +/* Which page is the flag stored in */ +#define FOLIO_PF_ANY 0 +#define FOLIO_PF_HEAD 0 +#define FOLIO_PF_NO_TAIL 0 +#define FOLIO_PF_NO_COMPOUND 0 +#define FOLIO_PF_SECOND 1 + +#define FOLIO_HEAD_PAGE 0 +#define FOLIO_SECOND_PAGE 1 + /* * Macros to create function definitions for page flags */ +#define FOLIO_TEST_FLAG(name, page) \ +static __always_inline bool folio_test_##name(const struct folio *folio) \ +{ return test_bit(PG_##name, const_folio_flags(folio, page)); } + +#define FOLIO_SET_FLAG(name, page) \ +static __always_inline void folio_set_##name(struct folio *folio) \ +{ set_bit(PG_##name, folio_flags(folio, page)); } + +#define FOLIO_CLEAR_FLAG(name, page) \ +static __always_inline void folio_clear_##name(struct folio *folio) \ +{ clear_bit(PG_##name, folio_flags(folio, page)); } + +#define __FOLIO_SET_FLAG(name, page) \ +static __always_inline void __folio_set_##name(struct folio *folio) \ +{ __set_bit(PG_##name, folio_flags(folio, page)); } + +#define __FOLIO_CLEAR_FLAG(name, page) \ +static __always_inline void __folio_clear_##name(struct folio *folio) \ +{ __clear_bit(PG_##name, folio_flags(folio, page)); } + +#define FOLIO_TEST_SET_FLAG(name, page) \ +static __always_inline bool folio_test_set_##name(struct folio *folio) \ +{ return test_and_set_bit(PG_##name, folio_flags(folio, page)); } + +#define FOLIO_TEST_CLEAR_FLAG(name, page) \ +static __always_inline bool folio_test_clear_##name(struct folio *folio) \ +{ return test_and_clear_bit(PG_##name, folio_flags(folio, page)); } + +#define FOLIO_FLAG(name, page) \ +FOLIO_TEST_FLAG(name, page) \ +FOLIO_SET_FLAG(name, page) \ +FOLIO_CLEAR_FLAG(name, page) + #define TESTPAGEFLAG(uname, lname, policy) \ -static __always_inline int Page##uname(struct page *page) \ - { return test_bit(PG_##lname, &policy(page, 0)->flags); } +FOLIO_TEST_FLAG(lname, FOLIO_##policy) \ +static __always_inline int Page##uname(const struct page *page) \ +{ return test_bit(PG_##lname, &policy(page, 0)->flags); } #define SETPAGEFLAG(uname, lname, policy) \ +FOLIO_SET_FLAG(lname, FOLIO_##policy) \ static __always_inline void SetPage##uname(struct page *page) \ - { set_bit(PG_##lname, &policy(page, 1)->flags); } +{ set_bit(PG_##lname, &policy(page, 1)->flags); } #define CLEARPAGEFLAG(uname, lname, policy) \ +FOLIO_CLEAR_FLAG(lname, FOLIO_##policy) \ static __always_inline void ClearPage##uname(struct page *page) \ - { clear_bit(PG_##lname, &policy(page, 1)->flags); } +{ clear_bit(PG_##lname, &policy(page, 1)->flags); } #define __SETPAGEFLAG(uname, lname, policy) \ +__FOLIO_SET_FLAG(lname, FOLIO_##policy) \ static __always_inline void __SetPage##uname(struct page *page) \ - { __set_bit(PG_##lname, &policy(page, 1)->flags); } +{ __set_bit(PG_##lname, &policy(page, 1)->flags); } #define __CLEARPAGEFLAG(uname, lname, policy) \ +__FOLIO_CLEAR_FLAG(lname, FOLIO_##policy) \ static __always_inline void __ClearPage##uname(struct page *page) \ - { __clear_bit(PG_##lname, &policy(page, 1)->flags); } +{ __clear_bit(PG_##lname, &policy(page, 1)->flags); } #define TESTSETFLAG(uname, lname, policy) \ +FOLIO_TEST_SET_FLAG(lname, FOLIO_##policy) \ static __always_inline int TestSetPage##uname(struct page *page) \ - { return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } +{ return test_and_set_bit(PG_##lname, &policy(page, 1)->flags); } #define TESTCLEARFLAG(uname, lname, policy) \ +FOLIO_TEST_CLEAR_FLAG(lname, FOLIO_##policy) \ static __always_inline int TestClearPage##uname(struct page *page) \ - { return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } +{ return test_and_clear_bit(PG_##lname, &policy(page, 1)->flags); } #define PAGEFLAG(uname, lname, policy) \ TESTPAGEFLAG(uname, lname, policy) \ @@ -302,45 +491,73 @@ static __always_inline int TestClearPage##uname(struct page *page) \ TESTSETFLAG(uname, lname, policy) \ TESTCLEARFLAG(uname, lname, policy) -#define TESTPAGEFLAG_FALSE(uname) \ +#define FOLIO_TEST_FLAG_FALSE(name) \ +static inline bool folio_test_##name(const struct folio *folio) \ +{ return false; } +#define FOLIO_SET_FLAG_NOOP(name) \ +static inline void folio_set_##name(struct folio *folio) { } +#define FOLIO_CLEAR_FLAG_NOOP(name) \ +static inline void folio_clear_##name(struct folio *folio) { } +#define __FOLIO_SET_FLAG_NOOP(name) \ +static inline void __folio_set_##name(struct folio *folio) { } +#define __FOLIO_CLEAR_FLAG_NOOP(name) \ +static inline void __folio_clear_##name(struct folio *folio) { } +#define FOLIO_TEST_SET_FLAG_FALSE(name) \ +static inline bool folio_test_set_##name(struct folio *folio) \ +{ return false; } +#define FOLIO_TEST_CLEAR_FLAG_FALSE(name) \ +static inline bool folio_test_clear_##name(struct folio *folio) \ +{ return false; } + +#define FOLIO_FLAG_FALSE(name) \ +FOLIO_TEST_FLAG_FALSE(name) \ +FOLIO_SET_FLAG_NOOP(name) \ +FOLIO_CLEAR_FLAG_NOOP(name) + +#define TESTPAGEFLAG_FALSE(uname, lname) \ +FOLIO_TEST_FLAG_FALSE(lname) \ static inline int Page##uname(const struct page *page) { return 0; } -#define SETPAGEFLAG_NOOP(uname) \ +#define SETPAGEFLAG_NOOP(uname, lname) \ +FOLIO_SET_FLAG_NOOP(lname) \ static inline void SetPage##uname(struct page *page) { } -#define CLEARPAGEFLAG_NOOP(uname) \ +#define CLEARPAGEFLAG_NOOP(uname, lname) \ +FOLIO_CLEAR_FLAG_NOOP(lname) \ static inline void ClearPage##uname(struct page *page) { } -#define __CLEARPAGEFLAG_NOOP(uname) \ +#define __CLEARPAGEFLAG_NOOP(uname, lname) \ +__FOLIO_CLEAR_FLAG_NOOP(lname) \ static inline void __ClearPage##uname(struct page *page) { } -#define TESTSETFLAG_FALSE(uname) \ +#define TESTSETFLAG_FALSE(uname, lname) \ +FOLIO_TEST_SET_FLAG_FALSE(lname) \ static inline int TestSetPage##uname(struct page *page) { return 0; } -#define TESTCLEARFLAG_FALSE(uname) \ +#define TESTCLEARFLAG_FALSE(uname, lname) \ +FOLIO_TEST_CLEAR_FLAG_FALSE(lname) \ static inline int TestClearPage##uname(struct page *page) { return 0; } -#define PAGEFLAG_FALSE(uname) TESTPAGEFLAG_FALSE(uname) \ - SETPAGEFLAG_NOOP(uname) CLEARPAGEFLAG_NOOP(uname) +#define PAGEFLAG_FALSE(uname, lname) TESTPAGEFLAG_FALSE(uname, lname) \ + SETPAGEFLAG_NOOP(uname, lname) CLEARPAGEFLAG_NOOP(uname, lname) -#define TESTSCFLAG_FALSE(uname) \ - TESTSETFLAG_FALSE(uname) TESTCLEARFLAG_FALSE(uname) +#define TESTSCFLAG_FALSE(uname, lname) \ + TESTSETFLAG_FALSE(uname, lname) TESTCLEARFLAG_FALSE(uname, lname) __PAGEFLAG(Locked, locked, PF_NO_TAIL) -PAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) __CLEARPAGEFLAG(Waiters, waiters, PF_ONLY_HEAD) -PAGEFLAG(Error, error, PF_NO_TAIL) TESTCLEARFLAG(Error, error, PF_NO_TAIL) -PAGEFLAG(Referenced, referenced, PF_HEAD) - TESTCLEARFLAG(Referenced, referenced, PF_HEAD) - __SETPAGEFLAG(Referenced, referenced, PF_HEAD) +FOLIO_FLAG(waiters, FOLIO_HEAD_PAGE) +FOLIO_FLAG(referenced, FOLIO_HEAD_PAGE) + FOLIO_TEST_CLEAR_FLAG(referenced, FOLIO_HEAD_PAGE) + __FOLIO_SET_FLAG(referenced, FOLIO_HEAD_PAGE) 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) + TESTCLEARFLAG(LRU, lru, PF_HEAD) +FOLIO_FLAG(active, FOLIO_HEAD_PAGE) + __FOLIO_CLEAR_FLAG(active, FOLIO_HEAD_PAGE) + FOLIO_TEST_CLEAR_FLAG(active, FOLIO_HEAD_PAGE) PAGEFLAG(Workingset, workingset, PF_HEAD) TESTCLEARFLAG(Workingset, workingset, 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 */ @@ -354,20 +571,20 @@ PAGEFLAG(XenRemapped, xen_remapped, PF_NO_COMPOUND) PAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) __CLEARPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) __SETPAGEFLAG(Reserved, reserved, PF_NO_COMPOUND) -PAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) - __CLEARPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) - __SETPAGEFLAG(SwapBacked, swapbacked, PF_NO_TAIL) +FOLIO_FLAG(swapbacked, FOLIO_HEAD_PAGE) + __FOLIO_CLEAR_FLAG(swapbacked, FOLIO_HEAD_PAGE) + __FOLIO_SET_FLAG(swapbacked, FOLIO_HEAD_PAGE) /* * 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 + * - PG_private and PG_private_2 cause release_folio() and co to be invoked */ -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) +PAGEFLAG(Private, private, PF_ANY) +FOLIO_FLAG(private_2, FOLIO_HEAD_PAGE) + +/* owner_2 can be set on tail pages for anon memory */ +FOLIO_FLAG(owner_2, FOLIO_HEAD_PAGE) /* * Only test-and-set exist for PG_writeback. The unconditional operators are @@ -375,13 +592,17 @@ PAGEFLAG(OwnerPriv1, owner_priv_1, PF_ANY) */ TESTPAGEFLAG(Writeback, writeback, PF_NO_TAIL) TESTSCFLAG(Writeback, writeback, PF_NO_TAIL) -PAGEFLAG(MappedToDisk, mappedtodisk, PF_NO_TAIL) +FOLIO_FLAG(mappedtodisk, FOLIO_HEAD_PAGE) /* PG_readahead is only used for reads; PG_reclaim is only for writes */ PAGEFLAG(Reclaim, reclaim, PF_NO_TAIL) TESTCLEARFLAG(Reclaim, reclaim, PF_NO_TAIL) -PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND) - TESTCLEARFLAG(Readahead, reclaim, PF_NO_COMPOUND) +FOLIO_FLAG(readahead, FOLIO_HEAD_PAGE) + FOLIO_TEST_CLEAR_FLAG(readahead, FOLIO_HEAD_PAGE) + +FOLIO_FLAG(dropbehind, FOLIO_HEAD_PAGE) + FOLIO_TEST_CLEAR_FLAG(dropbehind, FOLIO_HEAD_PAGE) + __FOLIO_SET_FLAG(dropbehind, FOLIO_HEAD_PAGE) #ifdef CONFIG_HIGHMEM /* @@ -389,59 +610,68 @@ PAGEFLAG(Readahead, reclaim, PF_NO_COMPOUND) * available at this point. */ #define PageHighMem(__p) is_highmem_idx(page_zonenum(__p)) +#define folio_test_highmem(__f) is_highmem_idx(folio_zonenum(__f)) #else -PAGEFLAG_FALSE(HighMem) +PAGEFLAG_FALSE(HighMem, highmem) #endif -#ifdef CONFIG_SWAP -static __always_inline int PageSwapCache(struct page *page) -{ -#ifdef CONFIG_THP_SWAP - page = compound_head(page); +/* Does kmap_local_folio() only allow access to one page of the folio? */ +#ifdef CONFIG_DEBUG_KMAP_LOCAL_FORCE_MAP +#define folio_test_partial_kmap(f) true +#else +#define folio_test_partial_kmap(f) folio_test_highmem(f) #endif - return PageSwapBacked(page) && test_bit(PG_swapcache, &page->flags); +#ifdef CONFIG_SWAP +static __always_inline bool folio_test_swapcache(const struct folio *folio) +{ + return folio_test_swapbacked(folio) && + test_bit(PG_swapcache, const_folio_flags(folio, 0)); } -SETPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) -CLEARPAGEFLAG(SwapCache, swapcache, PF_NO_TAIL) + +FOLIO_SET_FLAG(swapcache, FOLIO_HEAD_PAGE) +FOLIO_CLEAR_FLAG(swapcache, FOLIO_HEAD_PAGE) #else -PAGEFLAG_FALSE(SwapCache) +FOLIO_FLAG_FALSE(swapcache) #endif -PAGEFLAG(Unevictable, unevictable, PF_HEAD) - __CLEARPAGEFLAG(Unevictable, unevictable, PF_HEAD) - TESTCLEARFLAG(Unevictable, unevictable, PF_HEAD) +FOLIO_FLAG(unevictable, FOLIO_HEAD_PAGE) + __FOLIO_CLEAR_FLAG(unevictable, FOLIO_HEAD_PAGE) + FOLIO_TEST_CLEAR_FLAG(unevictable, FOLIO_HEAD_PAGE) #ifdef CONFIG_MMU -PAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) - __CLEARPAGEFLAG(Mlocked, mlocked, PF_NO_TAIL) - TESTSCFLAG(Mlocked, mlocked, PF_NO_TAIL) +FOLIO_FLAG(mlocked, FOLIO_HEAD_PAGE) + __FOLIO_CLEAR_FLAG(mlocked, FOLIO_HEAD_PAGE) + FOLIO_TEST_CLEAR_FLAG(mlocked, FOLIO_HEAD_PAGE) + FOLIO_TEST_SET_FLAG(mlocked, FOLIO_HEAD_PAGE) #else -PAGEFLAG_FALSE(Mlocked) __CLEARPAGEFLAG_NOOP(Mlocked) - TESTSCFLAG_FALSE(Mlocked) -#endif - -#ifdef CONFIG_ARCH_USES_PG_UNCACHED -PAGEFLAG(Uncached, uncached, PF_NO_COMPOUND) -#else -PAGEFLAG_FALSE(Uncached) +FOLIO_FLAG_FALSE(mlocked) + __FOLIO_CLEAR_FLAG_NOOP(mlocked) + FOLIO_TEST_CLEAR_FLAG_FALSE(mlocked) + FOLIO_TEST_SET_FLAG_FALSE(mlocked) #endif #ifdef CONFIG_MEMORY_FAILURE PAGEFLAG(HWPoison, hwpoison, PF_ANY) TESTSCFLAG(HWPoison, hwpoison, PF_ANY) #define __PG_HWPOISON (1UL << PG_hwpoison) -extern bool take_page_off_buddy(struct page *page); #else -PAGEFLAG_FALSE(HWPoison) +PAGEFLAG_FALSE(HWPoison, hwpoison) #define __PG_HWPOISON 0 #endif -#if defined(CONFIG_IDLE_PAGE_TRACKING) && defined(CONFIG_64BIT) -TESTPAGEFLAG(Young, young, PF_ANY) -SETPAGEFLAG(Young, young, PF_ANY) -TESTCLEARFLAG(Young, young, PF_ANY) -PAGEFLAG(Idle, idle, PF_ANY) +#ifdef CONFIG_PAGE_IDLE_FLAG +#ifdef CONFIG_64BIT +FOLIO_TEST_FLAG(young, FOLIO_HEAD_PAGE) +FOLIO_SET_FLAG(young, FOLIO_HEAD_PAGE) +FOLIO_TEST_CLEAR_FLAG(young, FOLIO_HEAD_PAGE) +FOLIO_FLAG(idle, FOLIO_HEAD_PAGE) +#endif +/* See page_idle.h for !64BIT workaround */ +#else /* !CONFIG_PAGE_IDLE_FLAG */ +FOLIO_FLAG_FALSE(young) +FOLIO_TEST_CLEAR_FLAG_FALSE(young) +FOLIO_FLAG_FALSE(idle) #endif /* @@ -452,40 +682,75 @@ PAGEFLAG(Idle, idle, PF_ANY) */ __PAGEFLAG(Reported, reported, PF_NO_COMPOUND) +#ifdef CONFIG_MEMORY_HOTPLUG +PAGEFLAG(VmemmapSelfHosted, vmemmap_self_hosted, PF_ANY) +#else +PAGEFLAG_FALSE(VmemmapSelfHosted, vmemmap_self_hosted) +#endif + /* - * On an anonymous page mapped into a user virtual memory area, - * page->mapping points to its anon_vma, not to a struct address_space; + * On an anonymous folio mapped into a user virtual memory area, + * folio->mapping points to its anon_vma, not to a struct address_space; * with the PAGE_MAPPING_ANON bit set to distinguish it. See rmap.h. * * On an anonymous page in a VM_MERGEABLE area, if CONFIG_KSM is enabled, * the PAGE_MAPPING_MOVABLE bit may be set along with the PAGE_MAPPING_ANON - * bit; and then page->mapping points, not to an anon_vma, but to a private + * bit; and then folio->mapping points, not to an anon_vma, but to a private * structure which KSM associates with that merged page. See ksm.h. * * PAGE_MAPPING_KSM without PAGE_MAPPING_ANON is used for non-lru movable - * page and then page->mapping points a struct address_space. + * page and then folio->mapping points to a struct movable_operations. + * + * Please note that, confusingly, "folio_mapping" refers to the inode + * address_space which maps the folio from disk; whereas "folio_mapped" + * refers to user virtual address space into which the folio is mapped. * - * Please note that, confusingly, "page_mapping" refers to the inode - * address_space which maps the page from disk; whereas "page_mapped" - * refers to user virtual address space into which the page is mapped. + * For slab pages, since slab reuses the bits in struct page to store its + * internal states, the folio->mapping does not exist as such, nor do + * these flags below. So in order to avoid testing non-existent bits, + * please make sure that folio_test_slab(folio) actually evaluates to + * false before calling the following functions (e.g., folio_test_anon). + * See mm/slab.h. */ #define PAGE_MAPPING_ANON 0x1 #define PAGE_MAPPING_MOVABLE 0x2 #define PAGE_MAPPING_KSM (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) #define PAGE_MAPPING_FLAGS (PAGE_MAPPING_ANON | PAGE_MAPPING_MOVABLE) -static __always_inline int PageMappingFlags(struct page *page) +static __always_inline bool folio_mapping_flags(const struct folio *folio) +{ + return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) != 0; +} + +static __always_inline bool PageMappingFlags(const struct page *page) { return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) != 0; } -static __always_inline int PageAnon(struct page *page) +static __always_inline bool folio_test_anon(const struct folio *folio) +{ + return ((unsigned long)folio->mapping & PAGE_MAPPING_ANON) != 0; +} + +static __always_inline bool PageAnonNotKsm(const struct page *page) +{ + unsigned long flags = (unsigned long)page_folio(page)->mapping; + + return (flags & PAGE_MAPPING_FLAGS) == PAGE_MAPPING_ANON; +} + +static __always_inline bool PageAnon(const struct page *page) { - page = compound_head(page); - return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0; + return folio_test_anon(page_folio(page)); } -static __always_inline int __PageMovable(struct page *page) +static __always_inline bool __folio_test_movable(const struct folio *folio) +{ + return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) == + PAGE_MAPPING_MOVABLE; +} + +static __always_inline bool __PageMovable(const struct page *page) { return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == PAGE_MAPPING_MOVABLE; @@ -498,30 +763,56 @@ static __always_inline int __PageMovable(struct page *page) * is found in VM_MERGEABLE vmas. It's a PageAnon page, pointing not to any * anon_vma, but to that page's node of the stable tree. */ -static __always_inline int PageKsm(struct page *page) +static __always_inline bool folio_test_ksm(const struct folio *folio) { - page = compound_head(page); - return ((unsigned long)page->mapping & PAGE_MAPPING_FLAGS) == + return ((unsigned long)folio->mapping & PAGE_MAPPING_FLAGS) == PAGE_MAPPING_KSM; } #else -TESTPAGEFLAG_FALSE(Ksm) +FOLIO_TEST_FLAG_FALSE(ksm) #endif -u64 stable_page_flags(struct page *page); +u64 stable_page_flags(const struct page *page); -static inline int PageUptodate(struct page *page) +/** + * folio_xor_flags_has_waiters - Change some folio flags. + * @folio: The folio. + * @mask: Bits set in this word will be changed. + * + * This must only be used for flags which are changed with the folio + * lock held. For example, it is unsafe to use for PG_dirty as that + * can be set without the folio lock held. It can also only be used + * on flags which are in the range 0-6 as some of the implementations + * only affect those bits. + * + * Return: Whether there are tasks waiting on the folio. + */ +static inline bool folio_xor_flags_has_waiters(struct folio *folio, + unsigned long mask) { - int ret; - page = compound_head(page); - ret = test_bit(PG_uptodate, &(page)->flags); + return xor_unlock_is_negative_byte(mask, folio_flags(folio, 0)); +} + +/** + * folio_test_uptodate - Is this folio up to date? + * @folio: The folio. + * + * The uptodate flag is set on a folio when every byte in the folio is + * at least as new as the corresponding bytes on storage. Anonymous + * and CoW folios are always uptodate. If the folio is not uptodate, + * some of the bytes in it may be; see the is_partially_uptodate() + * address_space operation. + */ +static inline bool folio_test_uptodate(const struct folio *folio) +{ + bool ret = test_bit(PG_uptodate, const_folio_flags(folio, 0)); /* - * 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 + * Must ensure that the data we read out of the folio is loaded + * _after_ we've loaded folio->flags to check the uptodate bit. + * We can skip the barrier if the folio is not uptodate, because * we wouldn't be reading anything from it. * - * See SetPageUptodate() for the other side of the story. + * See folio_mark_uptodate() for the other side of the story. */ if (ret) smp_rmb(); @@ -529,46 +820,73 @@ static inline int PageUptodate(struct page *page) return ret; } -static __always_inline void __SetPageUptodate(struct page *page) +static inline bool PageUptodate(const struct page *page) +{ + return folio_test_uptodate(page_folio(page)); +} + +static __always_inline void __folio_mark_uptodate(struct folio *folio) { - VM_BUG_ON_PAGE(PageTail(page), page); smp_wmb(); - __set_bit(PG_uptodate, &page->flags); + __set_bit(PG_uptodate, folio_flags(folio, 0)); } -static __always_inline void SetPageUptodate(struct page *page) +static __always_inline void folio_mark_uptodate(struct folio *folio) { - 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. + * so that all previous stores issued in order to bring the folio + * uptodate are actually visible before folio_test_uptodate becomes true. */ smp_wmb(); - set_bit(PG_uptodate, &page->flags); + set_bit(PG_uptodate, folio_flags(folio, 0)); +} + +static __always_inline void __SetPageUptodate(struct page *page) +{ + __folio_mark_uptodate((struct folio *)page); +} + +static __always_inline void SetPageUptodate(struct page *page) +{ + folio_mark_uptodate((struct folio *)page); } 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); +void __folio_start_writeback(struct folio *folio, bool keep_write); +void set_page_writeback(struct page *page); -#define test_set_page_writeback(page) \ - __test_set_page_writeback(page, false) -#define test_set_page_writeback_keepwrite(page) \ - __test_set_page_writeback(page, true) +#define folio_start_writeback(folio) \ + __folio_start_writeback(folio, false) +#define folio_start_writeback_keepwrite(folio) \ + __folio_start_writeback(folio, true) -static inline void set_page_writeback(struct page *page) +static __always_inline bool folio_test_head(const struct folio *folio) { - test_set_page_writeback(page); + return test_bit(PG_head, const_folio_flags(folio, FOLIO_PF_ANY)); } -static inline void set_page_writeback_keepwrite(struct page *page) +static __always_inline int PageHead(const struct page *page) { - test_set_page_writeback_keepwrite(page); + PF_POISONED_CHECK(page); + return test_bit(PG_head, &page->flags) && !page_is_fake_head(page); } -__PAGEFLAG(Head, head, PF_ANY) CLEARPAGEFLAG(Head, head, PF_ANY) +__SETPAGEFLAG(Head, head, PF_ANY) +__CLEARPAGEFLAG(Head, head, PF_ANY) +CLEARPAGEFLAG(Head, head, PF_ANY) + +/** + * folio_test_large() - Does this folio contain more than one page? + * @folio: The folio to test. + * + * Return: True if the folio is larger than one page. + */ +static inline bool folio_test_large(const struct folio *folio) +{ + return folio_test_head(folio); +} static __always_inline void set_compound_head(struct page *page, struct page *head) { @@ -586,168 +904,126 @@ static inline void ClearPageCompound(struct page *page) BUG_ON(!PageHead(page)); ClearPageHead(page); } -#endif - -#define PG_head_mask ((1UL << PG_head)) - -#ifdef CONFIG_HUGETLB_PAGE -int PageHuge(struct page *page); -int PageHeadHuge(struct page *page); -bool page_huge_active(struct page *page); +FOLIO_FLAG(large_rmappable, FOLIO_SECOND_PAGE) +FOLIO_FLAG(partially_mapped, FOLIO_SECOND_PAGE) #else -TESTPAGEFLAG_FALSE(Huge) -TESTPAGEFLAG_FALSE(HeadHuge) - -static inline bool page_huge_active(struct page *page) -{ - return 0; -} +FOLIO_FLAG_FALSE(large_rmappable) +FOLIO_FLAG_FALSE(partially_mapped) #endif +#define PG_head_mask ((1UL << PG_head)) #ifdef CONFIG_TRANSPARENT_HUGEPAGE /* - * PageHuge() only returns true for hugetlbfs pages, but not for - * normal or transparent huge pages. - * - * PageTransHuge() returns true for both transparent huge and - * hugetlbfs pages, but not normal pages. PageTransHuge() can only be - * called only in the core VM paths where hugetlbfs pages can't exist. - */ -static inline int PageTransHuge(struct page *page) -{ - VM_BUG_ON_PAGE(PageTail(page), page); - return PageHead(page); -} - -/* * PageTransCompound returns true for both transparent huge pages * and hugetlbfs pages, so it should only be called when it's known * that hugetlbfs pages aren't involved. */ -static inline int PageTransCompound(struct page *page) +static inline int PageTransCompound(const struct page *page) { return PageCompound(page); } +#else +TESTPAGEFLAG_FALSE(TransCompound, transcompound) +#endif +#if defined(CONFIG_MEMORY_FAILURE) && defined(CONFIG_TRANSPARENT_HUGEPAGE) /* - * PageTransCompoundMap is the same as PageTransCompound, but it also - * guarantees the primary MMU has the entire compound page mapped - * through pmd_trans_huge, which in turn guarantees the secondary MMUs - * can also map the entire compound page. This allows the secondary - * MMUs to call get_user_pages() only once for each compound page and - * to immediately map the entire compound page with a single secondary - * MMU fault. If there will be a pmd split later, the secondary MMUs - * will get an update through the MMU notifier invalidation through - * split_huge_pmd(). - * - * Unlike PageTransCompound, this is safe to be called only while - * split_huge_pmd() cannot run from under us, like if protected by the - * MMU notifier, otherwise it may result in page->_mapcount check false - * positives. - * - * We have to treat page cache THP differently since every subpage of it - * would get _mapcount inc'ed once it is PMD mapped. But, it may be PTE - * mapped in the current process so comparing subpage's _mapcount to - * compound_mapcount to filter out PTE mapped case. - */ -static inline int PageTransCompoundMap(struct page *page) -{ - struct page *head; - - if (!PageTransCompound(page)) - return 0; - - if (PageAnon(page)) - return atomic_read(&page->_mapcount) < 0; - - head = compound_head(page); - /* File THP is PMD mapped and not PTE mapped */ - return atomic_read(&page->_mapcount) == - atomic_read(compound_mapcount_ptr(head)); -} - -/* - * PageTransTail returns true for both transparent huge pages - * and hugetlbfs pages, so it should only be called when it's known - * that hugetlbfs pages aren't involved. - */ -static inline int PageTransTail(struct page *page) -{ - return PageTail(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. + * PageHasHWPoisoned indicates that at least one subpage is hwpoisoned in the + * compound page. * - * 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(). + * This flag is set by hwpoison handler. Cleared by THP split or free page. */ -PAGEFLAG(DoubleMap, double_map, PF_SECOND) - TESTSCFLAG(DoubleMap, double_map, PF_SECOND) +FOLIO_FLAG(has_hwpoisoned, FOLIO_SECOND_PAGE) #else -TESTPAGEFLAG_FALSE(TransHuge) -TESTPAGEFLAG_FALSE(TransCompound) -TESTPAGEFLAG_FALSE(TransCompoundMap) -TESTPAGEFLAG_FALSE(TransTail) -PAGEFLAG_FALSE(DoubleMap) - TESTSCFLAG_FALSE(DoubleMap) +FOLIO_FLAG_FALSE(has_hwpoisoned) #endif /* - * For pages that are never mapped to userspace (and aren't PageSlab), - * page_type may be used. Because it is initialised to -1, we invert the - * sense of the bit, so __SetPageFoo *clears* the bit used for PageFoo, and - * __ClearPageFoo *sets* the bit used for PageFoo. We reserve a few high and - * low bits so that an underflow or overflow of page_mapcount() won't be - * mistaken for a page type value. + * For pages that do not use mapcount, page_type may be used. + * The low 24 bits of pagetype may be used for your own purposes, as long + * as you are careful to not affect the top 8 bits. The low bits of + * pagetype will be overwritten when you clear the page_type from the page. */ +enum pagetype { + /* 0x00-0x7f are positive numbers, ie mapcount */ + /* Reserve 0x80-0xef for mapcount overflow. */ + PGTY_buddy = 0xf0, + PGTY_offline = 0xf1, + PGTY_table = 0xf2, + PGTY_guard = 0xf3, + PGTY_hugetlb = 0xf4, + PGTY_slab = 0xf5, + PGTY_zsmalloc = 0xf6, + PGTY_unaccepted = 0xf7, + PGTY_large_kmalloc = 0xf8, + + PGTY_mapcount_underflow = 0xff +}; -#define PAGE_TYPE_BASE 0xf0000000 -/* Reserve 0x0000007f to catch underflows of page_mapcount */ -#define PAGE_MAPCOUNT_RESERVE -128 -#define PG_buddy 0x00000080 -#define PG_offline 0x00000100 -#define PG_kmemcg 0x00000200 -#define PG_table 0x00000400 -#define PG_guard 0x00000800 +static inline bool page_type_has_type(int page_type) +{ + return page_type < (PGTY_mapcount_underflow << 24); +} -#define PageType(page, flag) \ - ((page->page_type & (PAGE_TYPE_BASE | flag)) == PAGE_TYPE_BASE) +/* This takes a mapcount which is one more than page->_mapcount */ +static inline bool page_mapcount_is_type(unsigned int mapcount) +{ + return page_type_has_type(mapcount - 1); +} -static inline int page_has_type(struct page *page) +static inline bool page_has_type(const struct page *page) { - return (int)page->page_type < PAGE_MAPCOUNT_RESERVE; + return page_type_has_type(data_race(page->page_type)); } -#define PAGE_TYPE_OPS(uname, lname) \ -static __always_inline int Page##uname(struct page *page) \ +#define FOLIO_TYPE_OPS(lname, fname) \ +static __always_inline bool folio_test_##fname(const struct folio *folio) \ { \ - return PageType(page, PG_##lname); \ + return data_race(folio->page.page_type >> 24) == PGTY_##lname; \ +} \ +static __always_inline void __folio_set_##fname(struct folio *folio) \ +{ \ + if (folio_test_##fname(folio)) \ + return; \ + VM_BUG_ON_FOLIO(data_race(folio->page.page_type) != UINT_MAX, \ + folio); \ + folio->page.page_type = (unsigned int)PGTY_##lname << 24; \ +} \ +static __always_inline void __folio_clear_##fname(struct folio *folio) \ +{ \ + if (folio->page.page_type == UINT_MAX) \ + return; \ + VM_BUG_ON_FOLIO(!folio_test_##fname(folio), folio); \ + folio->page.page_type = UINT_MAX; \ +} + +#define PAGE_TYPE_OPS(uname, lname, fname) \ +FOLIO_TYPE_OPS(lname, fname) \ +static __always_inline int Page##uname(const struct page *page) \ +{ \ + return data_race(page->page_type >> 24) == PGTY_##lname; \ } \ static __always_inline void __SetPage##uname(struct page *page) \ { \ - VM_BUG_ON_PAGE(!PageType(page, 0), page); \ - page->page_type &= ~PG_##lname; \ + if (Page##uname(page)) \ + return; \ + VM_BUG_ON_PAGE(data_race(page->page_type) != UINT_MAX, page); \ + page->page_type = (unsigned int)PGTY_##lname << 24; \ } \ static __always_inline void __ClearPage##uname(struct page *page) \ { \ + if (page->page_type == UINT_MAX) \ + return; \ VM_BUG_ON_PAGE(!Page##uname(page), page); \ - page->page_type |= PG_##lname; \ + page->page_type = UINT_MAX; \ } /* * PageBuddy() indicates that the page is free and in the buddy system * (see mm/page_alloc.c). */ -PAGE_TYPE_OPS(Buddy, buddy) +PAGE_TYPE_OPS(Buddy, buddy, buddy) /* * PageOffline() indicates that the page is logically offline although the @@ -756,64 +1032,144 @@ PAGE_TYPE_OPS(Buddy, buddy) * The content of these pages is effectively stale. Such pages should not * be touched (read/write/dump/save) except by their owner. * + * When a memory block gets onlined, all pages are initialized with a + * refcount of 1 and PageOffline(). generic_online_page() will + * take care of clearing PageOffline(). + * * If a driver wants to allow to offline unmovable PageOffline() pages without * putting them back to the buddy, it can do so via the memory notifier by * decrementing the reference count in MEM_GOING_OFFLINE and incrementing the * reference count in MEM_CANCEL_OFFLINE. When offlining, the PageOffline() - * pages (now with a reference count of zero) are treated like free pages, - * allowing the containing memory block to get offlined. A driver that + * pages (now with a reference count of zero) are treated like free (unmanaged) + * pages, allowing the containing memory block to get offlined. A driver that * relies on this feature is aware that re-onlining the memory block will - * require to re-set the pages PageOffline() and not giving them to the - * buddy via online_page_callback_t. + * require not giving them to the buddy via generic_online_page(). + * + * Memory offlining code will not adjust the managed page count for any + * PageOffline() pages, treating them like they were never exposed to the + * buddy using generic_online_page(). + * + * There are drivers that mark a page PageOffline() and expect there won't be + * any further access to page content. PFN walkers that read content of random + * pages should check PageOffline() and synchronize with such drivers using + * page_offline_freeze()/page_offline_thaw(). */ -PAGE_TYPE_OPS(Offline, offline) +PAGE_TYPE_OPS(Offline, offline, offline) -/* - * If kmemcg is enabled, the buddy allocator will set PageKmemcg() on - * pages allocated with __GFP_ACCOUNT. It gets cleared on page free. - */ -PAGE_TYPE_OPS(Kmemcg, kmemcg) +extern void page_offline_freeze(void); +extern void page_offline_thaw(void); +extern void page_offline_begin(void); +extern void page_offline_end(void); /* * Marks pages in use as page tables. */ -PAGE_TYPE_OPS(Table, table) +PAGE_TYPE_OPS(Table, table, pgtable) /* * Marks guardpages used with debug_pagealloc. */ -PAGE_TYPE_OPS(Guard, guard) +PAGE_TYPE_OPS(Guard, guard, guard) + +FOLIO_TYPE_OPS(slab, slab) + +/** + * PageSlab - Determine if the page belongs to the slab allocator + * @page: The page to test. + * + * Context: Any context. + * Return: True for slab pages, false for any other kind of page. + */ +static inline bool PageSlab(const struct page *page) +{ + return folio_test_slab(page_folio(page)); +} -extern bool is_free_buddy_page(struct page *page); +#ifdef CONFIG_HUGETLB_PAGE +FOLIO_TYPE_OPS(hugetlb, hugetlb) +#else +FOLIO_TEST_FLAG_FALSE(hugetlb) +#endif -__PAGEFLAG(Isolated, isolated, PF_ANY); +PAGE_TYPE_OPS(Zsmalloc, zsmalloc, zsmalloc) /* - * If network-based swap is enabled, sl*b must keep track of whether pages - * were allocated from pfmemalloc reserves. + * Mark pages that has to be accepted before touched for the first time. + * + * Serialized with zone lock. */ -static inline int PageSlabPfmemalloc(struct page *page) +PAGE_TYPE_OPS(Unaccepted, unaccepted, unaccepted) +FOLIO_TYPE_OPS(large_kmalloc, large_kmalloc) + +/** + * PageHuge - Determine if the page belongs to hugetlbfs + * @page: The page to test. + * + * Context: Any context. + * Return: True for hugetlbfs pages, false for anon pages or pages + * belonging to other filesystems. + */ +static inline bool PageHuge(const struct page *page) { - VM_BUG_ON_PAGE(!PageSlab(page), page); - return PageActive(page); + return folio_test_hugetlb(page_folio(page)); } -static inline void SetPageSlabPfmemalloc(struct page *page) +/* + * Check if a page is currently marked HWPoisoned. Note that this check is + * best effort only and inherently racy: there is no way to synchronize with + * failing hardware. + */ +static inline bool is_page_hwpoison(const struct page *page) { - VM_BUG_ON_PAGE(!PageSlab(page), page); - SetPageActive(page); + const struct folio *folio; + + if (PageHWPoison(page)) + return true; + folio = page_folio(page); + return folio_test_hugetlb(folio) && PageHWPoison(&folio->page); } -static inline void __ClearPageSlabPfmemalloc(struct page *page) +static inline bool folio_contain_hwpoisoned_page(struct folio *folio) { - VM_BUG_ON_PAGE(!PageSlab(page), page); - __ClearPageActive(page); + return folio_test_hwpoison(folio) || + (folio_test_large(folio) && folio_test_has_hwpoisoned(folio)); } -static inline void ClearPageSlabPfmemalloc(struct page *page) +bool is_free_buddy_page(const struct page *page); + +PAGEFLAG(Isolated, isolated, PF_ANY); + +static __always_inline int PageAnonExclusive(const struct page *page) { - VM_BUG_ON_PAGE(!PageSlab(page), page); - ClearPageActive(page); + VM_BUG_ON_PGFLAGS(!PageAnon(page), page); + /* + * HugeTLB stores this information on the head page; THP keeps it per + * page + */ + if (PageHuge(page)) + page = compound_head(page); + return test_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); +} + +static __always_inline void SetPageAnonExclusive(struct page *page) +{ + VM_BUG_ON_PGFLAGS(!PageAnonNotKsm(page), page); + VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); + set_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); +} + +static __always_inline void ClearPageAnonExclusive(struct page *page) +{ + VM_BUG_ON_PGFLAGS(!PageAnonNotKsm(page), page); + VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); + clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); +} + +static __always_inline void __ClearPageAnonExclusive(struct page *page) +{ + VM_BUG_ON_PGFLAGS(!PageAnon(page), page); + VM_BUG_ON_PGFLAGS(PageHuge(page) && !PageHead(page), page); + __clear_bit(PG_anon_exclusive, &PF_ANY(page, 1)->flags); } #ifdef CONFIG_MMU @@ -824,43 +1180,50 @@ static inline void ClearPageSlabPfmemalloc(struct page *page) /* * Flags checked when a page is freed. Pages being freed should not have - * these flags set. It they are, there is a problem. + * these flags set. If they are, there is a problem. */ #define PAGE_FLAGS_CHECK_AT_FREE \ (1UL << PG_lru | 1UL << PG_locked | \ 1UL << PG_private | 1UL << PG_private_2 | \ 1UL << PG_writeback | 1UL << PG_reserved | \ - 1UL << PG_slab | 1UL << PG_active | \ - 1UL << PG_unevictable | __PG_MLOCKED) + 1UL << PG_active | \ + 1UL << PG_unevictable | __PG_MLOCKED | LRU_GEN_MASK) /* * Flags checked when a page is prepped for return by the page allocator. - * Pages being prepped should not have these flags set. It they are set, + * Pages being prepped should not have these flags set. If they are set, * there has been a kernel bug or struct page corruption. * * __PG_HWPOISON is exceptional because it needs to be kept beyond page's * alloc-free cycle to prevent from reusing the page. */ #define PAGE_FLAGS_CHECK_AT_PREP \ - (((1UL << NR_PAGEFLAGS) - 1) & ~__PG_HWPOISON) + ((PAGEFLAGS_MASK & ~__PG_HWPOISON) | LRU_GEN_MASK | LRU_REFS_MASK) + +/* + * Flags stored in the second page of a compound page. They may overlap + * the CHECK_AT_FREE flags above, so need to be cleared. + */ +#define PAGE_FLAGS_SECOND \ + (0xffUL /* order */ | 1UL << PG_has_hwpoisoned | \ + 1UL << PG_large_rmappable | 1UL << PG_partially_mapped) #define PAGE_FLAGS_PRIVATE \ (1UL << PG_private | 1UL << PG_private_2) /** - * page_has_private - Determine if page has private stuff - * @page: The page to be checked + * folio_has_private - Determine if folio has private stuff + * @folio: The folio to be checked * - * Determine if a page has private stuff, indicating that release routines + * Determine if a folio has private stuff, indicating that release routines * should be invoked upon it. */ -static inline int page_has_private(struct page *page) +static inline int folio_has_private(const struct folio *folio) { - return !!(page->flags & PAGE_FLAGS_PRIVATE); + return !!(folio->flags & PAGE_FLAGS_PRIVATE); } #undef PF_ANY #undef PF_HEAD -#undef PF_ONLY_HEAD #undef PF_NO_TAIL #undef PF_NO_COMPOUND #undef PF_SECOND |