* [9fans] PC's 16MB SEGMAPSIZE limitations.
@ 1998-08-03 9:54 forsyth
0 siblings, 0 replies; 6+ messages in thread
From: forsyth @ 1998-08-03 9:54 UTC (permalink / raw)
>>I tried bumping SEGMAPSIZE to 64 and the machine became unstable.
that's enough for me on dozens of machines, with no instability.
^ permalink raw reply [flat|nested] 6+ messages in thread
* [9fans] PC's 16MB SEGMAPSIZE limitations.
@ 1998-08-04 22:15 Erik
0 siblings, 0 replies; 6+ messages in thread
From: Erik @ 1998-08-04 22:15 UTC (permalink / raw)
forsyth@caldo.demon.co.uk wrote:
> >>I tried bumping SEGMAPSIZE to 64 and the machine became unstable.
>
> that's enough for me on dozens of machines, with no instability.
Sorry, spoke too soon. The instability wasn't caused by SEGMAPSIZE. I
guess I applied the updates too hastily. :)
Apparently there is some incompatibility between my #9 Motion 771 VLB
card and the 9/pc/vgargb524.c hardware cursor stuff. After commenting
out the hwgc entry in vgadb the problem went away.
Symptoms included black screens of death when resizing windows and/or
moving the mouse, sending the monitor into a out-of-sync tailspin,
hanging the machine, and frying the local kfs file system.
The hung machine and tossed file system seem to be a fairly strange
effects for hwgc incompatibilities. I wonder if there isn't a bad
pointer in the code somewhere.
Any thoughts on this? Thanks.
Ciao,
Erik
^ permalink raw reply [flat|nested] 6+ messages in thread
* [9fans] PC's 16MB SEGMAPSIZE limitations.
@ 1998-08-01 22:47 Erik
0 siblings, 0 replies; 6+ messages in thread
From: Erik @ 1998-08-01 22:47 UTC (permalink / raw)
After applying all the AT&T updates to "Plan 9", I tried to rebuild the
world. Several items refused to compile due to "out of mem"
conditions, namely some of the larger things in libtiff.
After digging around, I see that the maximum segment size is 16MB for
PCs (mem.h - SEGMAPSIZE). This would explain the behavior I'm seeing
out of the 8c compiler as it uses sbrk to extend its BSS segment up to
16MB before it dies.
I tried bumping SEGMAPSIZE to 64 and the machine became unstable. Seems
there are other hard coded limits throughout the Plan 9 PC kernel, 16,
64, 128 etc. It appears that the maximum process footprint is limited
to 64MB. This is a truly sad condition for modern machines.
Has anyone had luck getting the 9 PC kernel out of the 16MB gear?
Ciao,
Erik
^ permalink raw reply [flat|nested] 6+ messages in thread
* [9fans] PC's 16MB SEGMAPSIZE limitations.
@ 1998-08-01 20:27 jmk
0 siblings, 0 replies; 6+ messages in thread
From: jmk @ 1998-08-01 20:27 UTC (permalink / raw)
a% grep SEGMAPSIZE /sys/src/brazil/pc/mem.h
#define SEGMAPSIZE 512
a%
--jim
^ permalink raw reply [flat|nested] 6+ messages in thread
* [9fans] PC's 16MB SEGMAPSIZE limitations.
@ 1998-08-01 19:54 dina
0 siblings, 0 replies; 6+ messages in thread
From: dina @ 1998-08-01 19:54 UTC (permalink / raw)
>This should be a FAQ.
>
working on it.
D i n a Li g h t
e: dina@untitled.net
+++++++++++++++++++++++++++++++++++++++++++
Serious error.
All shortcuts have disappeared.
Screen. Mind. Both are blank.
+++++++++++++++++++++++++++++++++++++++++++
^ permalink raw reply [flat|nested] 6+ messages in thread
* [9fans] PC's 16MB SEGMAPSIZE limitations.
@ 1998-08-01 19:33 Russ
0 siblings, 0 replies; 6+ messages in thread
From: Russ @ 1998-08-01 19:33 UTC (permalink / raw)
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.
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1998-08-03 9:54 [9fans] PC's 16MB SEGMAPSIZE limitations forsyth
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1998-08-04 22:15 Erik
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1998-08-01 20:27 jmk
1998-08-01 19:54 dina
1998-08-01 19:33 Russ
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