Ksplice: kernel patches without reboots

Which is why phone switches like the AT&T 5ESS were designed such that the control processor
(running Unix) could be rebooted without disrupting phone calls.  At worst it introduced a
slight delay in a subscriber getting a dial tone if they picked up just as the system was
rebooting.

No clever patch mechanism necessary.

For something more complex than a phone switch, in-service-upgrade is more difficult, so this
patch mechanism may be very useful.