* Vlastimil Babka [off-list ref] [2020-03-17 16:29:21]:

quoted

If we pass this node 0 (which is memoryless/cpuless) to
alloc_pages_node. Please note I am only setting node_numa_mem only
for offline nodes. However we could change this to set for all offline and
memoryless nodes.

That would indeed make sense.

But I guess that alloc_pages would still crash as the result of
numa_to_mem_node() is not passed down to alloc_pages() without this patch. In
__alloc_pages_node() we currently have "The node must be valid and online" so
offline nodes don't have zonelists. Either they get them, or we indeed need
something like this patch. But in order to not make get_any_partial() dead code,
the final replacement of invalid node with a valid one should be done in
alloc_slab_page() I guess?

I am posting v2 with this change.

quoted

quoted

node_to_mem_node() could be just a shortcut for the first zone's node in the
zonelist, so that fallback follows the topology.

-- 
Thanks and Regards
Srikar Dronamraju