Path: utzoo!attcan!uunet!cbmvax!daveh
From: daveh@cbmvax.UUCP (Dave Haynie)
Newsgroups: comp.sys.amiga
Subject: Re: Amiga UNIX
Message-ID: <4148@cbmvax.UUCP>
Date: 29 Jun 88 16:35:12 GMT
References: <146@ssdis.UUCP>
Organization: Commodore Technology, West Chester, PA
Lines: 32

in article <146@ssdis.UUCP>, gsarff@ssdis.UUCP (gary sarff) says:
> Summary: processes and threads

> My point was that I have seen a great many
> statements like "unix processes are heavy, amiga's processes are light so 
> ours are better".  I was just making the point that threads buy you little
> "lightness" if there is only one process per thread.

But Amiga processes are always lighter than those on UNIX; they're basically
always threads.  Even if I'm not running multiple execution paths in any
single program, as long as I'm running multiple programs, I get the advantage
of a much faster context switch.  Since it's impossible to run an Amiga or,
I suspect, UNIX, with only one unit of execution, Amiga's always going to win
doing the same kinds of things.  Since we now have UNIX and AmigaOS running
on exactly the same piece of hardware, that's a little easier to see for
real instead of theory.

Under other conditions, I see the point you wanted to make.  Take something
like a UNIX process (a heavy process, that needs to swap MMU state for every
context switch), and allow multiple threads to run within the state space of
that process.  The thread need only a subset of the full process overhead --
it runs in the same address space, etc.  This kind of thread is only a CPU
overhead win if you're running a multi-threaded application.  Now you take 
away the underlying UNIX process, and you probably wind up with something
that looks like an Amiga task or process.

> Gary Sarff           {uunet|ihnp4|philabs}!spies!ssdis!gsarff

-- 
Dave Haynie  "The 32 Bit Guy"     Commodore-Amiga  "The Crew That Never Rests"
   {ihnp4|uunet|rutgers}!cbmvax!daveh      PLINK: D-DAVE H     BIX: hazy
		"I can't relax, 'cause I'm a Boinger!"