Path: utzoo!utgpu!jarvis.csri.toronto.edu!cs.utexas.edu!uwm.edu!psuvax1!husc6!encore!pinocchio!peralta
From: peralta@pinocchio.Encore.COM (Rick Peralta)
Newsgroups: comp.sys.sequent
Subject: Re: timing parallel programs
Summary: Wall clock time is not that bad for trend study on a quiet system.
Message-ID: <11171@encore.Encore.COM>
Date: 15 Feb 90 20:18:16 GMT
References: <1324@csisles.Bristol.AC.UK> <1803@baird.cs.strath.ac.uk> <LUIS.90Feb15104438@molly.octopus.tds.kth.se>
Sender: news@Encore.COM
Reply-To: peralta@multimax.encore.com (Rick Peralta)
Organization: Encore Computer Corp, Marlboro, MA
Lines: 17

In article luis@octopus.tds.kth.se (Luis Barriga) writes:
>
>2) I have read about a system call "getrusage" that gives info about
>resource utilization: system, user time consumed, and other stuff. Is
>there any problem using it?

It should be fine, just as long as you peek at it at the beginning and
end of your timing runs.  Otherwise you will get a little startup cost
into the overall measurements.  BTW: you'll need to sync the starts.

If you are interested in just general trends, just use the wall clock
time and test 0, 1 and many iterations of the code path.  That way you
can estimate fairly accurately how long things take, without going to
tremendous effort coding out the startup costs.


 - Rick