From owner-freebsd-current  Tue Nov  3 13:12:56 1998
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From: James Mansion <james@westongold.com>
To: Peter Wemm <peter@netplex.com.au>, Daniel Eischen <eischen@vigrid.com>
Cc: lists@tar.com, current@FreeBSD.ORG, jb@cimlogic.com.au
Subject: RE: Kernel threading (was Re: Thread Scheduler bug) 
Date: Mon, 2 Nov 1998 20:01:50 -0000 
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> From: Peter Wemm [mailto:peter@netplex.com.au]
> Sent: Sunday, November 01, 1998 3:30 PM
> ...
> - a "process" (struct proc) would have one or more threads, 
> all using the 
> same address space, pid, signals, etc.
> ...

I'd like to suggest that threads (at least kernel threads)
should share an address space EXCEPT for a page (or maybe
more than one) that will have a common address in each thread.

This is how OS/2 (at least) handles thread specific data,
and so far as I can tell it is potentially much cleaner
for TSD, including errno.

Any user-level multiplexing would need to save/restore this
data on task switch of course and a kernel-assist that changes
the memory map might be faster (or might not, dunno).

Can I ask (plead, really) for any effort in this area to
consider the support for inter-process synchronisation as well
as intra-process?

James

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