Real-Time OS

[Christian]

On Sun, May 21, 2000 at 06:53:49PM +0800, Nick Bannon wrote:
> Oh, certainly, and by taking the step to a system like QNX, perhaps,
> you can reduce that to microseconds. Interestingly enough, those
> sorts of numbers can be easy to achieve on tiny little microcontroller
> systems - they could be hundreds of times slower at processing than a
> desktop, but if you can wire up an interrupt line to the thing you're
> monitoring, or if you can afford to turn off interrupts and poll like
> mad, it's easy to get fast and deterministic response times.

Anyone got any idea how the RTLinux crowd performs in terms of response
times?

> > > On some systems (like Irix) you can say that some particular process is
> > > a "real-time" process, which means that if it wants to hold onto the
> [...]
> > Linux does this too.
> 
> I knew it did as an extension - Hard Hat Linux or RTLinux, for
> example, but I wasn't aware you could do that on a normal system.

Maybe we're talking about different things but from what I can tell the
sched_setscheduler(2) family implement POSIX (POSIX.1b?) real-time
extensions which is basically this sort of thing.  From what I gather
most CD burning software runs with the SCHED_FIFO policy.

Regards,

Christian.