Re: tasking, Cpu's, and more

[Mark Lundquist <mark@rational.com>]

G wrote:

> Hi all... I am back on topic now... so please forgive my brief
> outbursts of vociferous humanity...
>
> 1) If a program runs several tasks and the hardware has several CPU's.
> Does the whole
> process of coding the tasks require that a specific CPU is allocated to
> each one ?

Not necessarily....

>  I can understand how different threads of activity can be
> happening in different places, it just appears something less than
> transparent whether or not tasks must be assigned to system-specific
> CPU's.  This is a theoretical issue, I suppose.  I wonder because it
> might
> appear (to the novice/ interested individual) that different tasks
> performing different
> processes would require different coding for the relevant hardware
> functions and thus the task would have to be identified (in some way or
> another) with the relevant processor.  (?).  Is this so ?  If not, how
> would it be possible to ensure that a task
> was carried out in the right place ?   Does the code have to be written
> with hardware targets for the tasks ?

You might want to take a look at the RM, Annex E, which deals with
distributed computing.  Note that a single "processing node" as defined in
Annex E may in fact consist of multiple CPUs.  Also, the unit of
distribution is called a "partition", and it is much more general than just
"a task".