#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,
/* 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; }
#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
/*
#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)
#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
/*
static inline int PageAnon(struct page *page)
{
+ page = compound_head(page);
return ((unsigned long)page->mapping & PAGE_MAPPING_ANON) != 0;
}
*/
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);
}
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.
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);
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)
{
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)
{
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
/*
#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.
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.
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 */
projects / deliverable / linux.git / blobdiff