Subject: Why I wanted to tweak tickadj
To: None <>
From: der Mouse <mouse@Collatz.McRCIM.McGill.EDU>
List: current-users
Date: 12/06/1994 11:39:40
>>>>> I added tickadj to /kern.  [...]
>>>> 1) I already put it in sysctl, but I explicitly did *not* make it
>>>> writable.
>>> Then as far as my need goes you might as well not have bothered;
>>> the reason I put it there was so I could change it at runtime.
>> You've never justified *why* it's a good idea to patch it at
>> runtime.

It may not be, in general.  In my case, I had an adjustment large
enough that I didn't want to wait for the slow one-or-two-percent slew
tickadj tends to use; I cranked tickadj up until the machine's
time-of-day was ticking off seconds nearly twice as fast as my watch.
If I'd known what would come of it, I might have just gone ahead and
done it the other way, as a discontinuous step adjustment.

> [...NTP...]

I think NTP would really _like_ to tweak the tick size, instead of
having to constantly compensate with tickadj.  One thing on my
it-would-be-nice-to-do-someday list is to look at extending things so
that the clock tick size is kept in units much smaller than
microseconds (perhaps 2^-32 usec) so that it can be adjusted to very
fine precision, to match observed effective clock tick rates quite

					der Mouse