thp: transparent hugepage core

[linux-2.6-block.git] / include / linux / page-flags.h

diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 5f38c460367e41c1d9c7f9dab04fb2af993f52dc..4ca1241ef94e0796ee1c092eea25a5514c873821 100644 (file)
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -107,6 +107,9 @@ enum pageflags {
 #endif
 #ifdef CONFIG_MEMORY_FAILURE
        PG_hwpoison,            /* hardware poisoned page. Don't touch */
+#endif
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+       PG_compound_lock,
 #endif
        __NR_PAGEFLAGS,
 
@@ -198,7 +201,7 @@ static inline int __TestClearPage##uname(struct page *page) { return 0; }
 struct page;   /* forward declaration */
 
 TESTPAGEFLAG(Locked, locked) TESTSETFLAG(Locked, locked)
-PAGEFLAG(Error, error)
+PAGEFLAG(Error, error) TESTCLEARFLAG(Error, error)
 PAGEFLAG(Referenced, referenced) TESTCLEARFLAG(Referenced, referenced)
 PAGEFLAG(Dirty, dirty) TESTSCFLAG(Dirty, dirty) __CLEARPAGEFLAG(Dirty, dirty)
 PAGEFLAG(LRU, lru) __CLEARPAGEFLAG(LRU, lru)
@@ -344,7 +347,7 @@ static inline void set_page_writeback(struct page *page)
  * tests can be used in performance sensitive paths. PageCompound is
  * generally not used in hot code paths.
  */
-__PAGEFLAG(Head, head)
+__PAGEFLAG(Head, head) CLEARPAGEFLAG(Head, head)
 __PAGEFLAG(Tail, tail)
 
 static inline int PageCompound(struct page *page)
@@ -352,6 +355,13 @@ static inline int PageCompound(struct page *page)
        return page->flags & ((1L << PG_head) | (1L << PG_tail));
 
 }
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline void ClearPageCompound(struct page *page)
+{
+       BUG_ON(!PageHead(page));
+       ClearPageHead(page);
+}
+#endif
 #else
 /*
  * Reduce page flag use as much as possible by overlapping
@@ -389,14 +399,61 @@ static inline void __ClearPageTail(struct page *page)
        page->flags &= ~PG_head_tail_mask;
 }
 
+#ifdef CONFIG_TRANSPARENT_HUGEPAGE
+static inline void ClearPageCompound(struct page *page)
+{
+       BUG_ON((page->flags & PG_head_tail_mask) != (1 << PG_compound));
+       clear_bit(PG_compound, &page->flags);
+}
+#endif
+
 #endif /* !PAGEFLAGS_EXTENDED */
 
+#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(PageTail(page));
+       return PageHead(page);
+}
+
+static inline int PageTransCompound(struct page *page)
+{
+       return PageCompound(page);
+}
+
+#else
+
+static inline int PageTransHuge(struct page *page)
+{
+       return 0;
+}
+
+static inline int PageTransCompound(struct page *page)
+{
+       return 0;
+}
+#endif
+
 #ifdef CONFIG_MMU
 #define __PG_MLOCKED           (1 << PG_mlocked)
 #else
 #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.
@@ -406,7 +463,8 @@ static inline void __ClearPageTail(struct page *page)
         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)
+        1 << PG_unevictable | __PG_MLOCKED | __PG_HWPOISON | \
+        __PG_COMPOUND_LOCK)
 
 /*
  * Flags checked when a page is prepped for return by the page allocator.