Bumping MAXCPU for MIPS configurations

[Attilio Rao]

2011/6/29 Jayachandran C. <c.jayachandran at gmail.com>:
> On Wed, Jun 29, 2011 at 3:10 PM, Attilio Rao <attilio at freebsd.org> wrote:
>> [ Please CC me in replies as I'm not subscribed to this mailing list ]
>>
>> I'm planning to bump MAXCPU for all the kernel configurations
>> requiring it, as long as the latest cut of largeSMP changes is
>> completed.
>>
>> Anyway, I'm not really sure what MIPS configurations may benefit from
>> a larger number of MAXCPU. Probabilly XLP should, for what I've heard,
>> but I'd like to get a precise mapping between configurations that want
>> to bump the number and the actual maximum number of CPUs to be
>> supported.
>
> An XLP SoC has 32 cpus (8cores x 4 hw threads per core), and 4 of
> these can be interconnected to have upto 128 cpus.  We have an XLP
> port running on one chip with 32cpus, but there is interest in trying
> out 2 chip (64cpus) and 4 chip(128 cpus) configurations, so this is
> something I want to do when I get access to multi-chip boards for
> FreeBSD development.

I'll bump MAXCPU to 128 for XLP then, thanks.
Do you have informations about XLR?

> Each XLP SoC has built-in memory controllers, network accelerator,
> PCIe, UARTs, USB etc., so ideally we want to be NUMA aware rather than
> doing straight SMP across all the chips. But this is an area I have
> not looked into yet.

This is an area which should still improve a lot. So far we have only
a very basic support for NUMA, with dummy logic.

Thanks,
Attilio


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