About Multiprocessing

[Jiri Gaisler]

Joel Sherrill <joel at OARcorp.com> wrote:
> 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.
> 
> 
> If you have a way to tell which node you are on, the same text image 
> could work.  One copy of the code but multiple workspaces and BSSs.

This is good idea..! However, it does require that the code
is re-entrant - is that really the case? Isn't there any global
data structures in the .data segment which would preclude this
solution ..?

Jiri.