Disable realtime support by default.

This code is used only in a under development feature and it's not used
anywhere in the tree.

Allow to build it conditionally.

WHATS_NEW

@@ -1,5 +1,6 @@
 Version 2.02.54 -
 =====================================
+  Disable realtime support code by default.
   Make clvmd return 0 on success rather than 1.
   Add --pvmetadatacopies for pvcreate, vgcreate, vgextend, vgconvert.
   Add implict pvcreate support to vgcreate and vgextend.

configure

@@ -1508,7 +1508,7 @@ Optional Features:
   --enable-lvm1_fallback  Use this to fall back and use LVM1 binaries if
                           device-mapper is missing from the kernel
   --disable-readline      Disable readline support
-  --disable-realtime      Disable realtime clock support
+  --enable-realtime       Enable realtime clock support
   --enable-cmirrord       Enable the cluster mirror log daemon
   --enable-debug          Enable debugging
   --enable-profiling      Gather gcov profiling data
@@ -2226,7 +2226,6 @@ case "$host_os" in
 		ODIRECT=yes
 		DM_IOCTLS=yes
 		SELINUX=yes
-		REALTIME=yes
 		CLUSTER=internal
 		FSADM=yes
 		;;
@@ -2241,7 +2240,6 @@ case "$host_os" in
 		ODIRECT=no
 		DM_IOCTLS=no
 		SELINUX=no
-		REALTIME=no
 		CLUSTER=none
 		FSADM=no
 		;;

configure.in

@@ -40,7 +40,6 @@ case "$host_os" in
 		ODIRECT=yes
 		DM_IOCTLS=yes
 		SELINUX=yes
-		REALTIME=yes
 		CLUSTER=internal
 		FSADM=yes
 		;;
@@ -55,7 +54,6 @@ case "$host_os" in
 		ODIRECT=no
 		DM_IOCTLS=no
 		SELINUX=no
-		REALTIME=no
 		CLUSTER=none
 		FSADM=no
 		;;
@@ -318,7 +316,7 @@ AC_MSG_RESULT($READLINE)
 ################################################################################
 dnl -- Disable realtime clock support
 AC_MSG_CHECKING(whether to enable realtime support)
-AC_ARG_ENABLE(realtime, [  --disable-realtime      Disable realtime clock support],
+AC_ARG_ENABLE(realtime, [  --enable-realtime       Enable realtime clock support],
 REALTIME=$enableval)
 AC_MSG_RESULT($REALTIME)
 

lib/Makefile.in

@@ -82,7 +82,6 @@ SOURCES =\
 	misc/lvm-globals.c \
 	misc/lvm-string.c \
 	misc/lvm-wrappers.c \
-	misc/timestamp.c \
 	misc/util.c \
 	mm/memlock.c \
 	report/report.c \
@@ -90,6 +89,11 @@ SOURCES =\
 	uuid/uuid.c \
 	zero/zero.c
 
+ifeq ("@HAVE_REALTIME@", "yes")
+  SOURCES +=\
+	misc/timestamp.c
+endif
+
 ifeq ("@LVM1@", "internal")
   SOURCES +=\
 	format1/disk-rep.c \