Is it possible to increase the rate at which ntpd updates the system clock?
Solution 1:
The safe thing to do is to take down services then just set the clock. Such as with ntpdate, which tends to ship with a init script to do that at boot. Downtime isn't fun, but databases and other things don't like the clock going backwards.
The Linux adjtimex man page describes the system call used. Allowed offsets are measured in usec, it takes a long time to slew.