Re: powerpc,numa: Memory hotplug to memory-less nodes ?

From: Reza Arbab
Date: Wed May 11 2016 - 17:51:09 EST


On Mon, Jun 22, 2015 at 10:18:43AM +0530, Bharata B Rao wrote:
While developing memory hotplug support in QEMU for PoweKVM, I
realized that guest kernel has specific checks to prevent hot addition
of memory to a memory-less node.

I am referring to arch/powerpc/mm/numa.c:hot_add_scn_to_nid() which
has explicit checks to ensure that it returns a nid that has some some
memory (NODE_DATA(nid)->node_spanned_pages) even when user wants to
hotplug to a node that currently has zero memory.

Is this limitation by design ?

Sorry to resurrect such an old thread, but did anything come of this?

I've recently bumped into the same limitation. Could we consider removing it?

(I couldn't find the original distribution list for this thread. Please add whomever is appropriate to the Cc:)

--
Reza Arbab