Subject: Re: 350 pages wired down!
To: David Jones <>
From: Michael L. Hitch <>
List: amiga-dev
Date: 05/23/1994 21:46:21
On May 23, 11:02pm, David Jones wrote:
> But: Why do I have 313 pages wired down when in "normal" mode?  That's
> 2500K of memory gone, ostensibly for purposes internal to the kernel!
> I am assuming that the memory occupied by the kernel itself is not
> included in vmstat's total.  Even if it was, that's not sufficient
> to explain over 2 megs of internal use.

  One of the things the kernel does is allocate a rather large chunk
of memory for the kernel page table pages.  I think it was something
like 128 pages.  I've only seen about 5 to 7 pages actually being used.
The amiga/pmap.c routine "adjusts" the number of pages allocated if
the available memory is less than 4M, since things were getting to
the point where a 4M system just wouldn't run.

> I've only 8M of core, and if I can get some of that 2M back, my machine
> would be much happier under X.

  If you are building your own kernel, try changing amiga/pmap.c to
limit the number of KPT pages if there is less than 8M.  That should
help somewhat.


Michael L. Hitch			INTERNET:
Computer Consultant			BITNET:  OSYMH@MTSUNIX1.BITNET
Office of Systems and Computing Services
Montana State University	Bozeman, MT	USA