On Fri, Jun 25, 2021 at 09:02:17AM +0200, Andrew Jones wrote:
> On Fri, Jun 25, 2021 at 01:23:38PM +0800, Gavin Shan wrote:
> > The empty memory nodes, where no memory resides in, are allowed.
> > For these empty memory nodes, the 'len' of 'reg' property is zero.
> > The NUMA node IDs are still valid and parsed, but memory can be
> > added to them through hotplug afterwards. I finds difficulty to
> > get where it's properly documented.
> >
> > So lets add note to empty memory nodes in the NUMA binding doc.
> >
> > Signed-off-by: Gavin Shan <gshan@xxxxxxxxxx>
> > ---
> > Documentation/devicetree/bindings/numa.txt | 4 ++++
> > 1 file changed, 4 insertions(+)
> >
> > diff --git a/Documentation/devicetree/bindings/numa.txt b/Documentation/devicetree/bindings/numa.txt
> > index 21b35053ca5a..0fc882e44270 100644
> > --- a/Documentation/devicetree/bindings/numa.txt
> > +++ b/Documentation/devicetree/bindings/numa.txt
> > @@ -109,6 +109,10 @@ Example:
> > Dual socket system consists of 2 boards connected through ccn bus and
> > each board having one socket/soc of 8 cpus, memory and pci bus.
> >
> > +Note that empty memory nodes, which no memory resides in, are allowed.
> > +The NUMA node IDs in these empty memory nodes are still valid, but
> > +memory can be added into them through hotplug afterwards.
>
> Please change the second sentence to:
>
> The NUMA node IDs in these empty memory nodes are still valid and
> memory may be added into them through hotplug afterwards.
>
> But, this doesn't look like the right place for this paragraph. You're
> adding the paragraph to the example section, but the example doesn't have
> any empty memory nodes.
>
> I think the paragraph should be added to section "2 - numa-node-id" and an
Or maybe even create a new section for it.
> example empty memory node should be provided. Also, the commit message
> talks about the length of 'reg' being zero, which is an important
> distinction which should also be documented.
>
> Thanks,
> drew
>
> > +
> > memory@c00000 {
> > device_type = "memory";
> > reg = <0x0 0xc00000 0x0 0x80000000>;
> > --
> > 2.23.0
> >
