dmesg is filling with messages like:

xen_microtime[0]: clamping at 1147434187.352112 (-38840us)
xen_microtime[0]: clamping at 1147434187.352112 (-38727us)
xen_microtime[0]: clamping at 1147434187.352112 (-38602us)
xen_microtime[0]: clamping at 1147434187.352112 (-38486us)
xen_microtime[0]: clamping at 1147434187.352112 (-38374us)
xen_microtime[0]: clamping at 1147434187.352112 (-38232us)
xen_microtime[0]: clamping at 1147434187.352112 (-38116us)
xen_microtime[0]: clamping at 1147434187.352112 (-38004us)
xen_microtime[0]: clamping at 1147434187.352112 (-37878us)
xen_microtime[0]: clamping at 1147434187.352112 (-37762us)
xen_microtime[0]: clamping at 1147434187.352112 (-37650us)
xen_microtime[0]: clamping at 1147434187.352112 (-37525us)
xen_microtime[0]: clamping at 1147434187.352112 (-37409us)
xen_microtime[0]: clamping at 1147434187.352112 (-37297us)
xen_microtime[0]: clamping at 1147434187.352112 (-37159us)

How can the output be disabled?

-- 
John R. Shannon, CISSP
john@johnrshannon.com
jshannon@dsci-usa.com
john.r.shannon@us.army.mil
shannonjr@NetBSD.org