Subject: Re: poll(2)
To: Jonathan Stone <jonathan@dsg.stanford.edu>
From: Chris G Demetriou <Chris_G_Demetriou@auchentoshan.pdl.cs.cmu.edu>
List: tech-kern
Date: 12/09/1996 20:35:44
> AFAIK, there aren't yet any NetBSD ports with significantly
> better than millisecond time-of-day-clock (and thus forced process-
> scheduling) resolution. So milliseconds are currently as good as
> you'll get.
On a single-processor alpha, you can sanely get down-to-the-cycle time
of day clock resolution. You can't schedule on it, but you can get it
e.g. for microtime(), etc.
I implemented that in NetBSD/alpha (along with a memory mapped clock
that provided the same resolution), then yanked it because i didn't
want to create an interface which would be more or less impossible to
provide on MP systems.
Granted, that doesn't change what you're saying re: scheduling, but
when you add in the fact that the Alpha uses a 1024Hz real time clock
interrupt rate, which could be easily increased, well, you're still in
microseconds for scheduling, but are getting closer. It's just a
matter of time. 8-)
chris