This patch:

a) Fixes bug 858 (http://bugme.osdl.org/show_bug.cgi?id=858)
The problem was caused by round off error in calculating the correct 
jiffies value in micro seconds to do the round up to jiffies.  The fix 
is to do the round up AFTER conversion to jiffies, rather than before. 
  This only affected the timeval to jiffies calculation.

c.) Changed the scale values to get the highest possible precision 
short of going to full 64-bit math.  This is particularly useful in 
the scaling of the seconds part of time.  The code now computes a 
trial value at compile time and adjusts the scaling if the result is 
less than 32 bits.

b) Adds comments to time.h to remove (I hope) ALL the confusion that 
this file use to generate.

Please look over the comments, especially, and, if confusing, please 
suggest how they might be improved.
-- 
George Anzinger   george@mvista.com
High-res-timers:  http://sourceforge.net/projects/high-res-timers/
Preemption patch: http://www.kernel.org/pub/linux/kernel/people/rml