Re: [PATCH 2/2] ppc/pnv: Use the CPU topology to compute the default number of chips

["Cédric Le Goater" <clg@kaod.org>]

On 12/21/19 11:28 AM, Greg Kurz wrote:
> On Sat, 21 Dec 2019 11:39:06 +1100
> David Gibson <david@gibson.dropbear.id.au> wrote:
> 
>> On Fri, Dec 20, 2019 at 05:51:48PM +0100, Greg Kurz wrote:
>>> Multi TCG mandates the CPU topology to be dimensioned to the actual
>>> number of CPUs, depending on the number of chips the user asked for.
>>> That is, '-machine num-chips=N' should always have a '-smp' companion
>>> with a topology that meats the resulting number of CPUs, typically
>>> '-smp sockets=N'.
>>>
>>> Simplify the command line for these setups by computing the default
>>> number of chips based on the CPU topology, ie. no need to explicitely
>>> set "num-chips" anymore. This must be done at machine init because
>>> smp_parse() is called after instance init.
>>>
>>> Signed-off-by: Greg Kurz <groug@kaod.org>
>>
>> Is there actually any reason to retain num-chips at all?  Or could we
>> just set the number of chips equal to the number of sockets, which
>> seems to make sense to me.
>>
> 
> I don't quite know why "num-chips" was introduced in the first place... so
> yes, if it turns out it isn't needed, I'll gladly drop the property.

I concur. We have some freedom on the PowerNV machine options. 
Let's replace "num-chips" with "sockets".

Thanks,

C.