From: george anzinger <george@mvista.com>

This patch addresses issues of roundoff error in the time keeping and NTP
code as follows:

The conversion of "actual jiffies" to TICK_USEC and then to TICK_NSEC
introduced large errors if jiffies was not a power of 10 (e.g.  1024 for
the ia64).  Most of this is avoided by converting directly to TICK_NSEC.

The calculation of MAX_SEC_IN_JIFFIES (the largest timespec or timeval the
kernel will attempt) had overflow problems in the 64-bit machines.  We
introduce a different equation for those machines.

The NTP frequency update code was allowing a micro second of error to
accumulate before applying the correction.  We change FINEUSEC to FINENSEC
to do the correction as soon as a full nanosecond has accumulated.

The initial calculation of time_freq for NTP had severe roundoff errors for
HZ not a power of 10 (i.e.  1024).  A new equation fixes this.

clock_nanosleep is changed to round up to the next jiffie to cover starting
between jiffies.