On Tue, Jul 7, 2020 at 9:08 PM Justin He [off-list ref] wrote:
[..]

quoted

Especially for architectures that use memblock info for numa info
(which seems to be everyone except x86) why not implement a generic
memory_add_physaddr_to_nid() that does:

int memory_add_physaddr_to_nid(u64 addr)
{
        unsigned long start_pfn, end_pfn, pfn = PHYS_PFN(addr);
        int nid;

        for_each_online_node(nid) {
                get_pfn_range_for_nid(nid, &start_pfn, &end_pfn);
                if (pfn >= start_pfn && pfn <= end_pfn)
                        return nid;
        }
        return NUMA_NO_NODE;
}

Thanks for your suggestion,
Could I wrap the codes and let memory_add_physaddr_to_nid simply invoke
phys_to_target_node()?

I think it needs to be the reverse. phys_to_target_node() should call
memory_add_physaddr_to_nid() by default, but fall back to searching
reserved memory address ranges in memblock. See phys_to_target_node()
in arch/x86/mm/numa.c. That one uses numa_meminfo instead of memblock,
but the principle is the same i.e. that a target node may not be
represented in memblock.memory, but memblock.reserved. I'm working on
a patch to provide a function similar to get_pfn_range_for_nid() that
operates on reserved memory.

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