Re: Microblaze - The fist year

[Bill Davidsen <davidsen@tmr.com>]

Michael Schnell wrote:
> On 04/13/2010 03:27 PM, Michal Simek wrote:
>>
>> yes, futex is there. You can check it in
>> arch/microblaze/include/asm/futex.h
> Great ! I'll check how this is done.
>>
>>> Does Microblaze MMU Linux support SMP ?
>>
>> It is possible to connect several MicroBlazes but the problem is
>> missing cache coherency modul. I hope that Xilinx will release any
>> version which will support it.
>> We haven't done any significant work to support it but it is expected
>> solution which will happen.
>
> Besides cache coherency, another problem might be doing FUTEX. here (I
> suppose) SMP safe atomic user space operations are necessary. many
> simple RISK (load/store-) CPUs don't provide these (new ARMs provide
> "load-locked / store-conditional" on that behalf as an extension to the
> load/store paradigm. I suppose these can be done in an SMP-safe way,
> supposedly using the hardware that provides cache coherency).
>
I wonder if you could make this work with some variant of NUMA 
configuration. I don't predict anything about being practical even if it 
works, just a thought.

-- 
Bill Davidsen <davidsen@tmr.com>
   "We have more to fear from the bungling of the incompetent than from
the machinations of the wicked."  - from Slashdot