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From: "Petri Helenius" <pete@he.iki.fi>
To: "Julian Elischer" <julian@elischer.org>,
	"Jeff Roberson" <jroberson@chesapeake.net>
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Date: Mon, 30 Jun 2003 11:22:03 +0200
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cc: deischen@freebsd.org
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Subject: Re: rtprio and kse
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> 
> Theoretically any process with rt priority can monopolise the CPU if it
> spins, regardless of whether it's threaded or not..
> 
> Is not that what having RT-priority means?

Yes, but in non-threaded environment with multiple processes
competing for CPU libc is not expected to have locks. In threaded
environment it does have them around things like malloc. My concern
is the realtime thread spinlocking waiting for a lock which is held 
somewhere which does not get scheduled. These locks are not 
visible to the appliation and thus one must either put additional
mutexes around them or know that libc stuff is rtprio-thread-safe.

Pete