UNIX accounting statistics

[Mott Given]

   I have heard that block read/write counts in UNIX accounting statistics
   may have duplicate counts under some conditions.  For example, if process
   A and process B are sharing a memory buffer to do I/O, and process A
   does an I/O; then the block read/write counter is incremented for both
   process A and for process B.  Can anyone tell me if and when this actually
   happens?  I am working on UNIX modelling and any distortions in the
   accounting statistics could reduce the reliability of my results.  I am
   also interested in any other conditions where the accounting stats might
   over report or under report counts.

   We are running BSD 4.3 on a Gould 9050_PN.


Mott Given @ Defense Logistics Agency ,DSAC-TMP, Bldg. 27-1, P.O. Box 1605,
	    Systems Automation Center, Columbus, OH 43216-5002
UUCP:  mgiven%dsacg1.uucp at daitc.arpa              I speak for myself
Phone:       614-238-9431     AUTOVON: 850-9431
-- 
Mott Given @ Defense Logistics Agency ,DSAC-TMP, Bldg. 27-1, P.O. Box 1605,
	    Systems Automation Center, Columbus, OH 43216-5002
UUCP:  mgiven%dsacg1.uucp at daitc.arpa              I speak for myself
Phone:       614-238-9431     AUTOVON: 850-9431