Subject: Re: Configurable scheduler quantum?
To: Thorbjorn Jemander <thoan@ifm.liu.se>
From: Matthias Buelow <mkb@mukappabeta.de>
List: netbsd-users
Date: 05/03/2001 14:26:10
Thorbjorn Jemander writes:

>10 ms by setting the rrticks to hz/100. If I want values
>lower than that, say 5 or 3 ms I have to up the HZ value,
>but how does that affect the rest of the system? When

I wonder why you would want to do such a thing at all, generally
one would like to have as large quantums as possible without (human-)
noticable delays in context switching.  This has emperically been
determined to be about 1/10s (of course originally in larger
timesharing environments, where many users were using the computer
through a teletype or tube terminal, mostly typing at the keyboard
but I think Vahalia (can't check now) reports in his book that the
time quantum is also remarkable accurate in modern days (graphical,
mostly single-user environments) towards user expectations).  Do
you have any special use for your system in mind that would benefit
noticably from smaller quantums?  I'd be interested in what that
might be.

--mkb