+/* [(x + y - 1) / y] suffers from an integer overflow, even though the
+ * computation should be possible in the given type. Therefore, we use
+ * [x / y + !!(x % y)]. Note that on "Real CPUs" a division returns both the
+ * quotient and the remainder, so both should be equally fast. */
+#define DIV_ROUND_UP(_x, _y) \
+ __extension__ ({ \
+ const typeof(_x) __x = (_x); \
+ const typeof(_y) __y = (_y); \
+ (__x / __y + !!(__x % __y)); \
+ })
+