Newsgroups: comp.parallel,comp.parallel.mpi
From: Nicolas G Leshock <leshock@cse.psu.edu>
Subject: Determining CPU utilization accurately
Organization: PSU CSE Dept; US Army Signal Corps
Date: Tue, 1 Aug 1995 23:55:10 GMT
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Message-ID: <3v1o73$7ng@psuvax1.cse.psu.edu>

We are trying to compare the performance of parallel codes over 
different architectures. (LINUX PC net/SUN Sparc5 net/SP2) and are 
trying to get a firm picture of the amount of time that each task 
spends blocked waiting IO or message traffic.  We have tried using
MPI_Wtime which gives us an accurate wall clock measurement but when 
we compare that to getrusage calls for user time and system time the 
numbers fluctuate wildly, and sometimes even exceed the amount of 
time that Wtime says was spent processing.

If anyone has any experience or is familiar with any good net resources
for measuring performance and utilization, we would appreciate some help.

Thanks in advance.

Nick Leshock, leshock@cse.psu.edu
Isaac Ash, ash@cse.psu.edu



~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
~  Nick Leshock     email: ngl1@psu.edu,leshock@cse.psu.edu       ~
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~  "Go, sir, gallop, and don't forget that the world was made in  ~
~   six days.  You can ask me for anything you like, except       ~
~   time."                                                        ~
~                 Napoleon Bonaparte to an aide (1803)            ~
~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~


