From owner-freebsd-current  Sun Jan 31 02:57:12 1999
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Date: Sun, 31 Jan 1999 21:57:07 +1100
From: Bruce Evans <bde@zeta.org.au>
Message-Id: <199901311057.VAA08719@godzilla.zeta.org.au>
To: current@FreeBSD.ORG, dufault@hda.com
Subject: Re: more about yield() versus sched_yield()
Cc: bde@zeta.org.au
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>While we're discussing yield here's a question.
>
>The difference between yield() and sched_yield() is that yield unconditionally
>yields while sched_yield() won't if you are the highest priority process
>and the only process in your run queue.  Does anyone know the
>reuirements on yield() and would it continue to function for us if
>it worked the same as sched_yield()?

AFAIK (not far), yield() is not used, so there are no requirements on it.
It is certainly missing from libc (except as sycall(321)) and undocumented
in FreeBSD.

Another difference is that it correctly counts context switches as voluntary.

Bruce

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