About Multiprocessing

[Eric Valette]

Joel Sherrill <joel at OARcorp.com> wrote:
> 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.

As the SMP stuff periodically pops up, I always say the same thing:
current RTEMS locking sheme is absolutely not convénient for SMP systems
as it basically use IRQ disabling. This of course does not work on SMP
but replacing "irq disabling lock" by other locks (e.g masked spin
locks) would not work either because "irq disabling lock" can be nested
and unordered while SMP locks cannot usually.

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