thp: clear page compound
split_huge_page must transform a compound page to a regular page and needs
ClearPageCompound.
Signed-off-by: Andrea Arcangeli <aarcange@redhat.com>
Acked-by: Rik van Riel <riel@redhat.com>
Reviewed-by: Christoph Lameter <cl@linux-foundation.org>
Acked-by: Mel Gorman <mel@csn.ul.ie>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
diff --git a/include/linux/page-flags.h b/include/linux/page-flags.h
index 5a743cc..4835cae 100644
--- a/include/linux/page-flags.h
+++ b/include/linux/page-flags.h
@@ -347,7 +347,7 @@
* 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)
@@ -355,6 +355,13 @@
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
@@ -392,6 +399,14 @@
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_MMU