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From: prithvi@GAUGUIN.ART.CS.CMU.EDU (Prithvi Rao)
Newsgroups: comp.os.misc
Subject: Re: real time systems
Summary: real-time mach effort
Message-ID: <11901@pt.cs.cmu.edu>
Date: 12 Feb 91 03:24:52 GMT
References: <BK.91Feb7165840@benefit.cs.brown.edu> <62652@bbn.BBN.COM>
Distribution: comp
Organization: Carnegie-Mellon University, CS/RI
Lines: 24


	The work on real-time mach although still in it's infancy has
	some interesting results. We have defined a new real-time
	thread interface and have incorporated the rate-monotonic 
	scheduling policy. Essentially this comes down to having
	what we call an integrated time-driven scheduling scheme.
	We have been working on porting the pure-kernel(real-time version)
	to various platforms including the sony/NEWS and rs6000, r3000
	etc. We are working exclusively with the pure-kernel and adding
	the sporadic and deferrable server scheduling policies. We also
	have implemented the priority inheritance capability for 
	executing critical sections. 

	So we can create periodic and aperiodic threads and have some
	interesting applications to demonstrate the advantage of our
	real-time scheduling policies in real-time apllications. We
	emphasise predictability and so have a toolset that allows
	a user to monitor kernel scheduling activities.

	So at least this gives you a flavour of what we are up to in
	the real-time mach effort. There's lots more so if you're
	interested send me some mail.

	_prithvi