Message-Id:	<199703211124.NAA01960@laima.acad.latnet.lv>
From:	"Gints Linis" <gints AT acad DOT latnet DOT lv>
To:	<opendos-developer AT mail DOT tacoma DOT net>
Subject:	GDT size and limit of number of threads
Date:	Fri, 21 Mar 1997 13:27:33 +0200
MIME-Version:	1.0

> Just testing to see if anyone is actually here so that we can
> make a valient effort to move "developement related" discussions
> to this group instead of cluttering [opendos].

I have subscribed to opendos and -developer just recently, and so far this
is the first message I receive. I guess that my problem is
"development-related", so it should be relevant here. I had posted my
message to a couple of news-groups beforehand, but apparently OpenDOS is
outsides their scope of interest.

Thanks in advance for any help.

Gints Linis
University of Latvia
gints AT acad DOT latnet DOT lv

************************************
We are developing a real-time multi-threaded application, and for that we
have been trying to build an environment, which would support preemptive
thread switching in protected mode. 

Currently we are doing some experiments with OpenDOS (previously known as
Novell DOS 7.0). One of the first problems we have encountered is the
limited number of threads, namely we can create just a little more than 200
threads, but we would need more in our application.

The maximal number of threads that can exist in the system appears to be
connected with the size of GDT, since descriptors are being allocated to
threads directly from GDT. In the present configuration OpenDOS creates GDT
with 512 entries. We suppose that this is the reason why we can not create
more than 200+ threads at a time.

Could anyone tell the following:

- Is the 512 descriptors in GDT a principal limitation of this OS, or can
it be modified?

- What is the absolute maximal number of threads that can exist at a time?

- If the GDT size can be changed, then can it be done by means of e.g. a
configuration option, or it is possible exclusively through recompiling the
OS?

- Any ideas as to what else could be done to increase the maximal number of
threads?

I would also be thankful to learn about any experience with OpenDOS in
real-time applications, specially the performance issues.

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