Re: [PATCH v2 1/5] mm: add numa node symlink for memory section in sysfs

[Alex Chiang <achiang@hp.com>]

* David Rientjes <rientjes@google.com>:
> 
> Alex, I think the safest thing to do in unregister_mem_sect_under_nodes() 
> is to iterate though the section pfns and remove links to the node_device 
> kobjs for all the distinct pfn_to_nid()'s that it encounters.

Am I not understanding the code? It looks like we do this
already...

/* unregister memory section under all nodes that it spans */
int unregister_mem_sect_under_nodes(struct memory_block *mem_blk)
{
	nodemask_t unlinked_nodes;
	unsigned long pfn, sect_start_pfn, sect_end_pfn;

	if (!mem_blk)
		return -EFAULT;
	nodes_clear(unlinked_nodes);
	sect_start_pfn = section_nr_to_pfn(mem_blk->phys_index);
	sect_end_pfn = sect_start_pfn + PAGES_PER_SECTION - 1;
	for (pfn = sect_start_pfn; pfn <= sect_end_pfn; pfn++) {
		int nid;

		nid = get_nid_for_pfn(pfn);
		if (nid < 0)
			continue;
		if (!node_online(nid))
			continue;
		if (node_test_and_set(nid, unlinked_nodes))
			continue;
		sysfs_remove_link(&node_devices[nid].sysdev.kobj,
			 kobject_name(&mem_blk->sysdev.kobj));
		sysfs_remove_link(&mem_blk->sysdev.kobj,
			 kobject_name(&node_devices[nid].sysdev.kobj));
	}
	return 0;
}

Thanks,
/ac