Re: [RFC] [Patch 7/8] statistics infrastructure - exploitation prerequisite

[Peter Chubb]

>>>>> "Martin" == Martin Peschke <mp3@xxxxxxxxxx> writes:


Martin> I would be happy to exploit an API that may result from that
Martin> discussion.  I would plead for exporting such an API to
Martin> modules. I don't see how to implement statistics for
Martin> latencies, otherwise.

Martin> Any other hints on how to replace my sched_clock() calls are
Martin> welcome.  (I want to measure elapsed times in units that are
Martin> understandable to users without hardware manuals and
Martin> calculator, such as milliseconds.)

You may wish to look at the microstate accounting patches at
http://www.gelato.unsw.edu.au/cgi-bin/viewcvs.cgi/cvs/kernel/microstate/
I made the clock source configurable.

It's acually rather difficult to find a reliable cross-platform
monotonic clock with good resolution.  And different statistics may
want different clocks; for my purposes a cycle counter is best
(because I'm running on a machine that varies the clock speed for
power management reasons), other people may want nanoseconds.

-- 
Dr Peter Chubb  http://www.gelato.unsw.edu.au  peterc AT gelato.unsw.edu.au
http://www.ertos.nicta.com.au           ERTOS within National ICT Australia
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