From: combee AT cambridge DOT scr DOT slb DOT com (Leendert Combee)
Message-Id: <199706250723.IAA04387@tartan.scr.slb.com>
Subject: profiling...
To: djgpp AT delorie DOT com
Date: Wed, 25 Jun 1997 08:23:10 +0100 (BST)
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  I have been doing some profiling lately of my code compiled with
  (g)cc on unix and djgpp on dos/dosbox on win95. I have noticed
  a few things I can't explain:

  - my code does some I/O and takes a while to execute. I know much
    of the time is spent in the I/O. However, it doesnot show up
    in the djgpp profile data. In fact, profile data says a total execution
    time of a few seconds while my code runs for a minute or so.
    Profile results for other bits of my code seem OK, only the I/O
    bit seems to be wrong... Any ideas here? The profile data on 
    unix gcc are OK for I/O  and total.

  - For the reason of profiling, I did put the main part of my code
    into a 1000x loop. Now, if I run the code under plain DOS+cwsdpmi, indeed 
    I see the harddisk is accessed all the time (not swapping/paging!, just
    1000x file i/o); however, if I run the code from a dosbox/win95 (same 
    machine etc) I only see a harddisk access once and that's it. It still 
    takes about the same time to execute. I don't have smartdrive etc installed.
    Again, any ideas?

  Thanks for any help
    Leendert Combee