+#
+# Kernel version 3.17 introduced ktime_get_real_ts64
+#
+AC_DEFUN([LIBCFS_KTIME_GET_REAL_TS64],[
+LB_CHECK_COMPILE([does function 'ktime_get_real_ts64' exist],
+ktime_get_real_ts64, [
+ #include <linux/ktime.h>
+],[
+ struct timespec64 *ts = NULL;
+
+ ktime_get_real_ts64(ts);
+],[
+ AC_DEFINE(HAVE_KTIME_GET_REAL_TS64, 1,
+ ['ktime_get_real_ts64' is available])
+])
+]) # LIBCFS_KTIME_GET_REAL_TS64
+
+#
+# Kernel version 3.17 introduced ktime_get_real_seconds
+#
+AC_DEFUN([LIBCFS_KTIME_GET_REAL_SECONDS],[
+LB_CHECK_COMPILE([does function 'ktime_get_real_seconds' exist],
+ktime_get_real_seconds, [
+ #include <linux/ktime.h>
+],[
+ time64_t now;
+
+ now = ktime_get_real_seconds();
+],[
+ AC_DEFINE(HAVE_KTIME_GET_REAL_SECONDS, 1,
+ ['ktime_get_real_seconds' is available])
+])
+]) # LIBCFS_KTIME_GET_REAL_SECONDS
+
+#
+# Kernel version 3.17 created ktime_get_real_ns wrapper
+#
+AC_DEFUN([LIBCFS_KTIME_GET_REAL_NS],[
+LB_CHECK_COMPILE([does function 'ktime_get_real_ns' exist],
+ktime_get_real_ns, [
+ #include <linux/ktime.h>
+],[
+ u64 nanoseconds;
+
+ nanoseconds = ktime_get_real_ns();
+],[],[
+ AC_DEFINE(NEED_KTIME_GET_REAL_NS, 1,
+ ['ktime_get_real_ns' is not available])
+])
+]) # LIBCFS_KTIME_GET_REAL_NS
+
+#
+# Kernel version 3.17 introduced ktime_to_timespec64
+#
+AC_DEFUN([LIBCFS_KTIME_TO_TIMESPEC64],[
+LB_CHECK_COMPILE([does function 'ktime_to_timespec64' exist],
+ktime_to_timespec64, [
+ #include <linux/ktime.h>
+],[
+ struct timespec64 ts;
+ ktime_t now;
+
+ ts = ktime_to_timespec64(now);
+],[
+ AC_DEFINE(HAVE_KTIME_TO_TIMESPEC64, 1,
+ ['ktime_to_timespec64' is available])
+])
+]) # LIBCFS_KTIME_TO_TIMESPEC64
+
+#
+# Kernel version 3.19 introduced ktime_get_seconds
+#
+AC_DEFUN([LIBCFS_KTIME_GET_SECONDS],[
+LB_CHECK_COMPILE([does function 'ktime_get_seconds' exist],
+ktime_get_seconds, [
+ #include <linux/ktime.h>
+],[
+ time64_t now;