Re: [PATCH 2/4] mm/memory-hotplug: allow memory resources to be children

[Dave Hansen]

On 1/16/19 3:38 PM, Jerome Glisse wrote:
> So right now i would rather that we keep properly reporting this
> hazard so that at least we know it failed because of that. This
> also include making sure that we can not register private memory
> as a child of an un-busy resource that does exist but might not
> have yet been claim by its rightful owner.

I can definitely keep the warning in.  But, I don't think there's a
chance of HMM registering a IORES_DESC_DEVICE_PRIVATE_MEMORY region as
the child of another.  The region_intersects() check *should* find that:

>         for (; addr > size && addr >= iomem_resource.start; addr -= size) {
>                 ret = region_intersects(addr, size, 0, IORES_DESC_NONE);
>                 if (ret != REGION_DISJOINT)
>                         continue;