#define PG_head_tail_mask ((1L << PG_compound) | (1L << PG_reclaim))
-#define PageTail(page) ((page->flags & PG_head_tail_mask) \
+#define PageTail(page) (((page)->flags & PG_head_tail_mask) \
== PG_head_tail_mask)
static inline void __SetPageTail(struct page *page)
page->flags &= ~PG_head_tail_mask;
}
-#define PageHead(page) ((page->flags & PG_head_tail_mask) \
+#define PageHead(page) (((page)->flags & PG_head_tail_mask) \
== (1L << PG_compound))
#define __SetPageHead(page) __SetPageCompound(page)
#define __ClearPageHead(page) __ClearPageCompound(page)