About Multiprocessing

[Joel Sherrill <joel@OARcorp.com>]

Karel Gardas wrote:
> 
> Hello,
> 
> this is interesting, why is this this way? Nobody contributed SMP 
> support yet, or does real SMP support hurts real-time functionality? Or 
> is this just "historic relict"?

Yes.  Not really I would think.  Yes.

:-)


> Thanks,
> Karel
> 
> On Tue, 20 Dec 2005, Jiri Gaisler wrote:
> 
>>
>> We are currently developing an MP system with four LEON3 (SPARC)
>> cpus in a shared memory configuration. We are using the MP extensions
>> and memory-based communication, works fine so far. Pitty that RTEMS
>> doesn't have support for SMP, i.e. one image with multiple threads
>> executed by multiple cpus. eCos has this and it scales well up to
>> ~ four processors. With RTEMS, we must have a separate image for each
>> cpu, which wastes memory and complicates linking and program loading.
>>
>> Jiri.
>>
>> Ralf Corsepius wrote:
>>
>>> On Tue, 2005-12-20 at 20:11 +1100, Angelo Fraietta wrote:
>>>
>>>> there are over 40 CPUs (or rather BSPs) that RTEMS SUPPORTS
>>>
>>>
>>> ... but only 3 of these BSPs claim to support multiprocessing:
>>> m68k/mvme147s, m68k/mvme136, powerpc/psim :)
>>>
>>> i.e. multiprocessing for all cpus but the m68k and powerpc, probably has
>>> never been tested at all ;)
>>>
>>> Ralf
>>>
>>>
>>> .
>>>
>>
> 
> -- 
> Karel Gardas                  kgardas at objectsecurity.com
> ObjectSecurity Ltd.           http://www.objectsecurity.com


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