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Mail Archives: djgpp/2000/10/08/10:05:42

From: michael AT idisys DOT iae DOT nsk DOT su
Date: 8 Oct 2000 14:15:10 -0000
Message-ID: <20001008141510.8288.qmail@idisys.iae.nsk.su>
To: djgpp AT delorie DOT com
Subject: Re: Memory amount and PMODE
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In-Reply-To: <20001007141427.10046.qmail@idisys.iae.nsk.su> <7263-Sat07Oct2000203046+0300-eliz@is.elta.co.il>
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In article <7263-Sat07Oct2000203046+0300-eliz AT is DOT elta DOT co DOT il> you wrote:
> It looks like PMODE indeed doesn't support more than 64MB.

Is there a way to make sure it cannot be changed with run/compile-time
variables [first question]. Or maybe somebody know alternative DPMI
server - stub that can be bound to the executable without this limitation.

> In general, I would advise not to use PMODE unless you have a very
> good reason.  (For starters, it doesn't support virtual memory.)

Agreed, and I know that it doesnt support virtual memory, but imagine
that the program _must_ be a single execuable (it depends not on me - 
I would rather tune CWSDPMI parameters). The problem with virtual memory
is even deeper: this program starts from floppy to repair file system on
the local hard drive, so i cannot use default c:\cwsdpmi,swp, It would
be nice to have ability to enable/disable swap and change swap file path
(if there's a network drive for example) in the run-time (e.g to have
select_file_box() with checkbox "enable/disable swap" :). Because
I dont know if it possible with CWSDPMI or any other appropriate 
DPMI server [second question] I have no arguments to convince the 
customer, because to have additional executable is a very big minus
for him.

> I don't know.  But it strikes me that, since you have 128MB installed,
> there's no need to dig so deep into the library internals.  It is much
> easier (and more portable!) to change your data structures and/or
> algorithms so that it will use the available memory much more
> efficiently.

I'm trying to do my best with structures/algorithms :) but when I see the
library looses 30-50% of memory after sequence of reallocations (defragments),
and this memory could be used for drive cache, I understand this is the 
part killing efficiency. Anyway I know that STL discussion is offtopic and
we shouldnt discuss it here, but i still have 2 questions marked above.

 
Sincerely,
Michael

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