Mail Archives: djgpp/1998/08/30/09:54:44
On Wed, 26 Aug 1998, Endlisnis wrote:
> How come go32 gets 342 times more swap space? These were run
> one-after-the-other on the same dos box under Win95.
go32.exe reported swap space on the assumption that it (go32) is the
program that manages virtual memory. It is assuming this because
go32 is a full-fledged DOS extender which would load whenever any
DJGPP v1.x program was run, and manage almost everything a PM program
needs to run under DOS. (See section 21.2 of the DJGPP FAQ list, for
more about go32.exe.)
But this assumption breaks when DJGPP is run on Windows, since there
virtual memory is handled by Windows itself. So the swap space
reported by go32.exe on Windows is irrelevant to the amount of memory
your DJGPP v2 programs could use.
> These results seem fairly consistent, I've never got more than about
> 5 Megs of swap-space available. I have 4 drives, none have less
> than 300Megs free.
You seem to assume that what go32-v2 reports as ``swap space'' is
somehow related to the real free swap space available to Windows.
This assumption is incorrect. What go32-v2 reports is simply the
value that Windows fed it. Windows returns the free memory info in
the two values reported by go32-v2 in a way that only guarantees that
their sum is the total DPMI memory that a DJGPP program could use in
that DOS box. Its reports of the available physical memory is fairly
accurate, but the second number is just what it takes to make the sum
be the maximum available DPMI memory, it has nothing to do with the
swap space available to Windows itself.
What those numbers *really* mean is that your DOS box has only 16MB of
DPMI memory. The FAQ explains in section 15.6 how to enlarge that.
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