POSIX Mutex Performance

Gordon Scott g.rtems.a at gscott.co.uk
Thu Mar 25 16:36:17 UTC 2004


Hi all,

The whole of 'performance issue' is a classic benchmark conundrum.

	Which aspects of performance are most
	important in which context?

An RTOS's overiding constraints are normally predictable time
performance and robustness. Pure speed, even in a real-time context is
[usually?] secondary. If things aren't quick enough, revisit the
application's alogorithms, use a faster CPU, more appropriate class of
CPU, additional CPUs, better IO or whatever. Except in fairly
exceptional circumstances, hunting around in any decent mature RTOS for
a performance improvement is unlikely to deliver significant benefits.

The Linux kernel has been looked at and polished by lots of good people,
so it darned well should be quick and efficient. It will do many
RTOS-like things very well. But it isn't an RTOS.

FWIW, a main part of my personal philosophy on real-time is to try and
make everything less urgent than everything else. That means that only
the stuff that's _really_ urgent needs the CPU right now this
microsecond.

-- 
Gordon Scott				  http://www.gscott.co.uk

		Linux ... Because I like to *get* there today.

Hey, I'm looking for a new job!           See ->  http://www.gscott.co.uk






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