Re: [PATCH 1/3] powerpc/mm/hash: Avoid resizing-down HPT on first memory hotplug

Hello David, thanks for your feedback.

On Mon, 2021-03-22 at 17:49 +1100, David Gibson wrote:

I don't love this approach.  Adding the extra flag at this level seems
a bit inelegant, and it means we're passing up an easy opportunity to
reduce our resource footprint on the host.

I understand, but trying to reduce resource footprint in host, and
mostly failing is what causes hot-add and hot-remove to take so long.

But... maybe we'll have to do it.  I'd like to see if we can get
things to work well enough with just the "batching" to avoid multiple
resize attempts first.

This batching is something I had thought a lot about.
Problem is that there are a lot of generic interfaces between memory
hotplug and actually resizing HPT. I tried a simpler approach in
patches 2 & 3, so I don't touch much stuff there.

Best regards,
Leonardo Bras