Date: Mon, 5 Jul 2004 19:55:41 -0400 (EDT) From: Daniel Eischen <eischen@vigrid.com> To: Julian Elischer <julian@elischer.org> Cc: freebsd-threads@freebsd.org Subject: Re: pthread switch (was Odd KSE panic) Message-ID: <Pine.GSO.4.10.10407051951010.23911-100000@pcnet5.pcnet.com> In-Reply-To: <Pine.BSF.4.21.0407051539010.66234-100000@InterJet.elischer.org>
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On Mon, 5 Jul 2004, Julian Elischer wrote: > On Mon, 5 Jul 2004, Daniel Eischen wrote: > > > > It doesn't matter which thread gets run after the I/O thread > > calls pthread_cond_signal(). Either way, the I/O thread has > > to reenter the kernel and wait for the next event. And that > > time adds to the latency of the worker thread the _next_ time. > > not assuming that the worker thread tries to see if there is more work > before it yields. > > All I'm saying is that the app should decide the priority. > and you agree that it would be quicker in the case of the > 1KSE case? Latency is reduced, but overall throughput(*) is also reduced because of the extra thread switch for every wakeup. (*) Assuming that events occur fast enough. I'll have a look at adding preemption points, but I still have my doubts that it really matters... -- Dan Eischen
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