:
I think this patch is convenience even when memory hotplug is disabled.
CONFIG_SPARSEMEM seems better than CONFIG_MEMORY_HOTPLUG_SPARSE.
(snip)
If the first page of the section is not valid, then this section_nr_to_nid()
doesn't return correct value.
I tested this patch. In my box, the start_pfn of node 1 is 1200400, but
section_nr_to_pfn(mem_blk->phys_index) returns 1200000. As a result,
the section is linked to node 0.
Bye.
--
Yasunori Goto
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