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From: Samy Al Bahra <samy@kerneled.org>
To: Dan Langille <dan@langille.org>
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Date: Thu, 09 Jun 2005 05:11:00 +0300
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Cc: freebsd-threads@FreeBSD.org
Subject: Re: no kernel threads => no true multi tasking?
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On Wed, 2005-06-08 at 21:59 -0400, Dan Langille wrote:
> Folks,
> 
> I don't know enough to reply this this post:
> 
> http://article.gmane.org/gmane.comp.sysutils.backup.bacula.devel/2879
> 
> The part I'm concerned about:
> 
> "As far as I know, this only happens on FreeBSD 4.11 systems where 
> there are no kernel threads and hence no true multi-tasking. More 
> precisely, there is no task scheduling (time-sharing) between the 
> threads."

4.X used a user-space scheduling system (longjmp-based). So, basically,
threads operate with-in the time-slice of the process (every thread
would gratuitiously pass control over to another thread). 

The Linux threads FAQ covers this, it is available here:
http://www.tldp.org/FAQ/Threads-FAQ/Types.html

--
Samy Al Bahra