[PATCH] ntp: convert to the NTP4 reference model

[PATCH] ntp: convert to the NTP4 reference model

This converts the kernel ntp model into a model which matches the nanokernel
reference implementations.  The previous patches already increased the
resolution and precision of the computations, so that this conversion becomes
quite simple.

<linux@horizon.com> explains:

The original NTP kernel interface was defined in units of microseconds.
That's what Linux implements.  As computers have gotten faster and can now
split microseconds easily, a new kernel interface using nanosecond units was
defined ("the nanokernel", confusing as that name is to OS hackers), and
there's an STA_NANO bit in the adjtimex() status field to tell the application
which units it's using.

The current ntpd supports both, but Linux loses some possible timing
resolution because of quantization effects, and the ntpd hackers would really
like to be able to drop the backwards compatibility code.

Ulrich Windl has been maintaining a patch set to do the conversion for years,
but it's hard to keep in sync.

Signed-off-by: Roman Zippel <zippel@linux-m68k.org>
Cc: john stultz <johnstul@us.ibm.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>