Real-Time task vs. device driver vs. sched_setscheduler?

Real-Time task vs. device driver vs. sched_setscheduler?

Post by Robert W. Brew » Tue, 18 Mar 1997 04:00:00

I'm new to the idea of real-time operations, and I notice
that Linux supports "soft" real-time via sched_setscheduler()
and "hard" real-time via the RT-Linux kernel patches.

I'd greatly appreciate if someone could discuss the tradeoffs among
using a kernel device driver, the RT-Linux extensions, and the
sched_setscheduler() calls for a given application.  How would I know
what is a good match to an application?  Or would applications use
several of those methods together?  The examples I've seen for
RT-Linux sound like things that a device driver should handle.  Why
not use device drivers instead?  Or should the suggestion given in one
of the RT-Linux papers be followed: rewrite the time-dependent device
drivers as RT tasks?

Also, has anyone measured the maximum interrupt latency for RT-Linux?

Thanks for any insights.

Robert W. Brewer  


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