On 1/20/21 1:30 AM, Oscar Salvador wrote:

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

quoted

+ * 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.

Thanks.  I made that typo when fixing up some trivial checkpatch warnings.
Lesson learned (again), nothing is too trivial not to introduce erros.

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?

Yes, hugetlb_init is a better location for the BUILD_BUG_ON.  I initially
put it there before creating the !CONFIG_HUGETLB_PAGE version of the macros.
With the !CONFIG_HUGETLB_PAGE versions, none of the flags are ever used so
it is OK if the BUILD_BUG_ON is not included if !CONFIG_HUGETLB_PAGE.

-- 
Mike Kravetz