lkml.org 
[lkml]   [2006]   [May]   [16]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
 
Messages in this thread
/
Date
From
SubjectRe: [RFC] [Patch 7/8] statistics infrastructure - exploitation prerequisite
>>>>> "Martin" == Martin Peschke <mp3@de.ibm.com> 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
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@vger.kernel.org
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/

\
 
 \ /
  Last update: 2006-05-17 03:17    [from the cache]
©2003-2011 Jasper Spaans