Re: [Qemu-devel] [PATCH v3 4/8] Extend the command-line to provide memory latency and bandwidth information

[Eduardo Habkost <ehabkost@redhat.com>]

On Wed, Feb 06, 2019 at 11:11:24AM +0100, Igor Mammedov wrote:
> On Thu, 31 Jan 2019 15:16:54 +0800
> Tao Xu <tao3.xu@intel.com> wrote:
> 
> > From: Liu Jingqi <jingqi.liu@intel.com>
> > 
> > Add -numa hmat-lb option to provide System Locality Latency and
> > Bandwidth Information. These memory attributes help to build
> > System Locality Latency and Bandwidth Information Structure(s)
> > in ACPI Heterogeneous Memory Attribute Table (HMAT).
> Maybe instead of adding/using more globals since the rest of numa.c was
> written so, it's time to introduce NumaMachine type which inherits
> form base Machine and extends it with numa extensions.

I don't think inheritance is the right solution here.  We have
multiple features that are not available in all machines and:
SMP, ACPI, CPU hotplug, memory hotplug, etc.  We don't have
separate machine subclasses for each of these features.

Why would NUMA deserve having its own class in the machine type
hierarchy?

> 
> You don't have to refactor all old numa code for that (just the parts
> you use in HMAT) and later we could gradually refactor the rest of
> numa handling.
> 
> 
-- 
Eduardo