From:	"Charles M. Dude" <dude AT hal DOT io DOT com>
Newsgroups:	comp.os.msdos.djgpp
Subject:	Compiled programs LAG terribly
Date:	Thu, 25 Jun 1998 21:06:55 +0200
Organization:	Regional Computing Center, University of Cologne
Lines:	36
Message-ID:	<35929FCF.9EC9820@hal.io.com>
NNTP-Posting-Host:	annexr2-22.slip.uni-koeln.de
Mime-Version:	1.0
To:	djgpp AT delorie DOT com
DJ-Gateway:	from newsgroup comp.os.msdos.djgpp

Hi,

I have a small c-program which processes and evaluates measure data. The
program used to run on Unix systems ( i586-Linux, DEC Alpha/OSF1 ) and
there it worked fine and fast. Now I want to use it under Msdos / Win3.1
/ 95, and there the trouble starts. Compilation works fine, but when I
start the executable (in a test mode, like progname --help to get a
standard message, just to see wether it works) it takes about one or two
minutes before the program prompts with the help screen. During this
time, the computer seems to access the hard disk constantly ( but I have
the feeling that it doesn´t really read or write anything. This would
sound different ;) ). Anyways, on a comparable Unix machine, the same
procedure takes not even half a second - it is executed immediately.

The program usually processes relatively large pieces of data, and on
startup it has to do some memory management. I tried to profile it, as
described in the FAQ. And yes, the program spends 70% of its time in a
function called dpmi_int. I played around with the dpmi-configuration
also: More swap space, less swap space... Swap file on ram disk..
whatever, the lag remains. The Machine I use is a Pentium 100, 32MB RAM;
dpmi has about 12MB RAM and 128MB swap space at its disposal.

I would have given up by now, and blame msdos for all. But I tried to
compile and execute the program on different computers, all in all five
pentium machines with plenty of RAM and >90Mhz. On ONE of them the
program worked as expected - no lag! The solution seemed to be obvious -
there must be differences in the system configuration. Unfortunately
there are no remarkable differences.

At this point I´m stuck, and I hope that some of you have encountered
similar problems; I´d appreciate any ideas, comments whatever....

Thanks for your time,
Theo

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