Re: [uCsimm] For exact date

From: Larry Doolittle (
Date: Fri Mar 10 2000 - 14:45:56 EST

> If the DragonBall's crystal is 32.768 kHz, and you divide by 328 to get
> the interrupt, time_adjust_step is 10010, and time_adj is close to
> (1e6/(32768/328)-10010)*2^22, or -983040 (I think I got that right).
> Again, small corrections to time_adj are possible and recommended.

This assumes that it's desirable to keep HZ == 100. The kernel
doesn't really care, you could set it to 64, and everything would
work just fine. For that case, time_adjust_step is 15625, and
time_adj could get set back to zero. Unfortunately, there is a
fair amount of broken code floating around that assumes HZ == 100.
Linus discovered some of that when he set HZ == 1024 for the Alpha
to allow more responsive task-switching.

     - Larry
This message resent by the list server

This archive was generated by hypermail 2b30 : Sun Apr 07 2002 - 00:01:34 EST