From: "John M. Aldrich" <fighteer AT cs DOT com>
Newsgroups: comp.os.msdos.djgpp
Subject: Re: mem alloc taking up power of 2
Date: Tue, 22 Jul 1997 15:35:37 +0000
Organization: Two pounds of chaos and a pinch of salt
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Esa Peuha wrote:
> 
> True, but it must still allocate enough _disk space_ for it. The DPMI
> host can't know that you'll never touch that memory, and it must be able
> to page it in physical RAM if you do.
> 
> > The only thing being wasted is a few meg of your 32 bit
> > linear address space, but there's plenty of that to go around :-)
> 
> Disk space (in the swap file) is also being wasted, and this may be a
> problem.

Nothing is actually written to the swap file until touching a page of
memory requires swapping out a page in physical memory.  cwsdpmi is very
intelligent about this; those extra 20k blocks should never actually
take up space in the swap file.  However, they do count towards the
total memory that can be allocated.

AFAIK, allocated memory always remains purely "virtual" until it is
actually used.

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