[libvirt-users] questions on clock catchup

In http://libvirt.org/formatdomain.html#elementsTime , we could find there are three attributes of catchup tickpolicy: limit, threshold and slew. " The catchup element has three optional attributes, each a positive integer. The attributes are threshold, slew, and limit. " The xml format likes: <clock offset='utc'> <timer name='rtc' tickpolicy='catchup'> <catchup slew='123'/> or <catchup threshold='123'/> or <catchup limit='123'/> </timer> </clock> But there is no further explanation. Does anyone know what's the meaning of these attributes ? Best wishes, Jincheng Miao