Microsoft Word & (SCO) Unix 3.2

Peter da Silva peter at ficc.uu.net
Fri Aug 25 03:15:29 AEST 1989


In article <31897 at ism780c.isc.com>, darryl at ism780c.isc.com (Darryl Richman) writes:
> The emulator actually gets memory a 64k segment at a time and doles it
> out as the XENIX program sbrks for it.

This behaviour indeed speeds up most UNIX programs. However, programs written
using Intel's UDI interface, such as their PLM286 compiler and associated
tools, end up requesting 64K for all memory requests. This tends to lead to
processes that are very large, creates inordinate amounts of thrashing, and
even runs out of virtual memory space if the program makes frequent requests
for small amounts of memory.

The problem seems to be caused by intel's UDI returning a new segment for
every memory request. In real Xenix-286, small segments are returned for
small requests. In the emulator, all segments returned by x286emul are 64K
in size. We'd really really like to see this fixed, since it makes the
difference between being able to upgrade to System V and staying with the
System-III-based Xenix-286.
-- 
Peter da Silva, *NIX support guy @ Ferranti International Controls Corporation.
Biz: peter at ficc.uu.net, +1 713 274 5180. Fun: peter at sugar.hackercorp.com. `-_-'
"export ENV='${Envfile[(_$-=1)+(_=0)-(_$-!=_${-%%*i*})]}'" -- Tom Neff     'U`
"I didn't know that ksh had a built-in APL interpreter!" -- Steve J. Friedl



More information about the Comp.unix.i386 mailing list