Server product kernel requirements

[Peter Robinson]

>> On 10/30/2013 07:50 PM, David Strauss wrote:
>>> I was, indeed, drawing an arbitrary line, but we must draw the line somewhere.
>>> Maybe Fedora 23+ have it set far higher. It's easy to adapt over time to support
>>> the high end of commodity servers while still being desktop-friendly; we don't
>>> have a long support window.
>>>
>>
>> Fair enough, but my question is, then, why 512?  If it is completely arbitrary
>> why not jump it to a high number that people have requested before and be done
>> with it?  Even 1024 would be acceptable to the HPC users I've talked with FWIW.
>>
>> Josh, would you be okay with 1024?
>
> Maybe?  That seems like it would be fairly reasonable, but knowing
> what the overhead numbers are would help.  To be clear, right now we
> have things set thusly for NR_CPUS:
>
> arm=8
> ppc32=4
> ppc64/ppc64p7=1024
> s390x=64
> i686=32
> x86_64=128
>
> I believe our specific discussion here is about x86_64.  I don't think
> we're going to change i686 to anything higher than what it's set at
> right now.

Even with x86_64 I'm not sure most individual HPC devices have that
many cores from my experience. Most tend to go for most bang for your
buck and have more nodes. In the enterprise server space the
cores/threads tend to top out at around 160 at the moment (8 sockets,
10 cores, 2 threads). The exception here tends to be the few massive
NUMA box shippers and I'm not sure many of those would be looking at
Fedora, and would likely need custom kernels anyway.

Peter