From mboxrd@z Thu Jan  1 00:00:00 1970
Date: Sat,  1 Aug 1998 18:47:00 -0400
From: Erik Theisen etheisen@mindspring.com
Subject: [9fans] PC's 16MB SEGMAPSIZE limitations.
Topicbox-Message-UUID: 7be90c7c-eac8-11e9-9e20-41e7f4b1d025
Message-ID: <19980801224700.m9roV4zeRFwJ3XwslDI3UwTpX2SHmd-6OYuYnG-XmbU@z>

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