[Qemu-devel] Re: [PATCH 3/8] v2: add info numa monitor command

[Andre Przywara <andre.przywara@amd.com>]

Anthony Liguori wrote:

> So the current code limits us to 64-cpus?  That's a pretty serious 
> limitation IMHO.
I know, but I was hoping that a simpler patch would be easier to merge. 
So I am happy to fix it later and lift this restriction.
I searched for some kind of variable length bitmap type (like Linux' 
cpu_set_t) already being used in QEMU, but couldn't find anything 
appropriate. Do you know something? If you look at the glibc cpu_set_t 
implementation (in bits/sched.h), you surely want to make this a 
separate patch.

> I think that strongly suggests we're using the wrong 
> structures for node_to_cpus--especially to be in the BIOS FW interface.
Ok, this could be a point, but is this BIOS FW interface really a stable 
interface we cannot change later easily? IMHO this is QEMU (and derived 
projects) only, which always provide a matching BIOS anyway.

What about if I prepare the BIOS FW interface for future expansion and 
stick to the current uint64_t type for now?

Regards,
Andre.

And by the way: 64 core machines are _not_ common today, especially not 
when hosting pure QEMU :-)

-- 
Andre Przywara
AMD-Operating System Research Center (OSRC), Dresden, Germany
Tel: +49 351 277-84917
----to satisfy European Law for business letters:
AMD Saxony Limited Liability Company & Co. KG,
Wilschdorfer Landstr. 101, 01109 Dresden, Germany
Register Court Dresden: HRA 4896, General Partner authorized
to represent: AMD Saxony LLC (Wilmington, Delaware, US)
General Manager of AMD Saxony LLC: Dr. Hans-R. Deppe, Thomas McCoy