RE: thread ids, task ids and subsystems

[Volkmar Uhlig]

> -----Original Message-----
> From: Marcus Brinkmann [mailto:address@hidden 
> Sent: Wednesday, April 02, 2003 6:13 PM
>
> The root server considers all threads with a subsystem of 0, or with a
> thread number of 0 (masking out the subsystem bits) as privileged, and
> allows those threads to control *any* other thread.  (This is 
> important as you must be able to create, control and destroy one 
> subsystem from another one for debugging and maintenance).  The root 
> server itself does not need to keep any state: It just checks bits in 
> the thread id.  The responsibility to manage thread numbers and
version 
> numbers is completely within the special 0 threads.  It also contains 
> no mechanism to concurrently allocate unique subsystem ids, although 
> that is something you might want in a real world system (but that
could 
> be added later).

Marcus,

having a single privileged thread will result in poor SMP performance,
since you have to IPC cross processor. That will add significant latency
to thread creation/deletion. You should therefore have one privileged
HURD thread per physical processor.

- Volkmar