[9fans] PC's 16MB SEGMAPSIZE limitations.

[Russ Cox rsc@plan9.bell-labs.com]

This should be a FAQ.


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To: cse.psu.edu!9fans
Date: Wed, 29 Oct 1997 00:43:58 -0500
Subject: re: [9fans] How much memory does it require ...
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This got tossed around two years ago, and I think the
resolution was that you could change SEGMAPSIZE in pc/mem.h
and all would be fine.  The two attached messages contain
the necessary bits I think.

Nigel Roles said once that 8l uses 20MB to link ghostscript
without any printer drivers.

Russ

--- forwarded messages follow ---
 From cse.psu.edu!9fans-outgoing-owner Thu Nov  2 13:36:19 EST 1995
From:	"G. David Butler" <gdb@dbSystems.com>
To:	9fans@cse.psu.edu
Subject: Re: 386 maximum segment size of 16Mb
Sender: owner-9fans@cse.psu.edu
Reply-To: 9fans@cse.psu.edu

I hate replying to my own mail, but I guess I wasn't finished... :-)

>The real question, has anybody looked into increasing this limit?  (look
>in /sys/src/9/pc/mem.h, SEGMEMSIZE, I think, set to 16.)
Make that                SEGMAPSIZE.

Also several of the machines have this in mem.h:

#define SEGMAPSIZE 64 /* 16 is for wooses */

This would imply that all is necessary is to change 16 to 64 in pc/mem.h,
but that would be too simple...

Thanks again.

 From cse.psu.edu!9fans-outgoing-owner Thu Nov  2 13:59:19 EST 1995
From:	philw@plan9.att.com
To:	9fans@cse.psu.edu
Subject: Re: 386 maximum segment size of 16Mb
Sender: owner-9fans@cse.psu.edu
Reply-To: 9fans@cse.psu.edu


changing SEGMAPSIZE works fine.
It incurs overhead allocated Segment structures
so 16 seemed reasonable for a terminal. We really
dont use PC's to compile.