On Tue, Jan 19, 2021 at 05:30:45PM -0800, Mike Kravetz wrote:

+ * Macros to create test, set and clear function definitions for
+ * hugetlb specific page flags.
+ */
+#ifdef CONFIG_HUGETLB_PAGE
+#define TESTHPAGEFLAG(uname, flname)				\
+static inline int HPage##uname(struct page *page)		\
+	{ BUILD_BUG_ON(sizeof_field(struct page, private) *	\
+			BITS_PER_BYTE < __NR_HPAGEFLAGS);	\
+	return test_bit(HPG_##flname, &(page->private)); }
+
+#define SETHPAGEFLAG(uname, flname)				\
+static inline void SetHPage##uname(struct page *page)		\
+	{ set_bit(HPG_##flname, &(page->private)); }
+
+#define CLEARHPAGEFLAG(uname, flname)				\
+static inline void ClearHPage##uname(struct page *page)		\
+	{ clear_bit(HPG_##flname, &(page->private)); }
+#else
+#define TESTHPAGEFLAG(uname, flname)				\
+static inline int HPage##uname(struct page *page)		\
+	{ BUILD_BUG_ON(sizeof_field(struct page, private) *	\
+			BITS_PER_BYTE < __NR_HPAGEFLAGS);	\
+	return 0 }

You missed a ";" right there.

I might be missing something, but I do not think we need a BUILD_BUG_ON there
when CONFIG_HUGETLB_PAGE is not set?
Actually, would make more sense to move the BUILD_BUG_ON from above to
hugetlb_init?

Other than that, looks good to me, and I think it is a great improvment
towards readability and maintability.

-- 
Oscar Salvador
SUSE L3