From now on, monotonic clocks are used by default: this is much safer and

should not be too expensive.

configure.ac

@@ -448,8 +448,8 @@ AC_MSG_CHECKING(performance models location)
 AC_MSG_RESULT($perf_model_dir)
 
 # On many multicore CPUs, clock cycles are not synchronized
-AC_ARG_ENABLE(sync-clock, [AS_HELP_STRING([--enable-sync-clock], [Use monotonic clocks])],
-		enable_sync_clock=$enableval, enable_sync_clock=no)
+AC_ARG_ENABLE(sync-clock, [AS_HELP_STRING([--disable-sync-clock], [Do not use monotonic clocks])],
+		enable_sync_clock=$enableval, enable_sync_clock=yes)
 AC_MSG_CHECKING(whether using a synchronous clock)
 AC_MSG_RESULT($enable_sync_clock)
 if test x$enable_sync_clock = xyes; then