Re: Hard Real-Time?

[Sad Clouds <cryintothebluesky%gmail.com@localhost>]

On Sun, 19 Apr 2020 15:27:16 +0200
Johnny Billquist <bqt%update.uu.se@localhost> wrote:

> Essentially, a hard real time system guarantees that it never takes 
> longer than some specified time for something to happen. And as far
> as I know, NetBSD cannot give such guarantees. Various combinations
> of events and situations can lock out interrupts for some time, and
> there is no guaranteed upper bound to that time.

Yes you're right, "hard real time" is more about not missing deadlines,
rather than how fast something can be executed. Also the consequences of
missing deadlines can be quite catastrophic, i.e. air bags not
activating in time during a collision.

The original poster mentioned something about controlling a robot with
a raspberry pi. If the robot is not doing anything safety critical,
then "soft real time" is probably something that NetBSD could provide.