Hello Bharata, thanks for this feedback!

On Wed, 2020-03-04 at 10:13 +0530, Bharata B Rao wrote:

Hi,

I tried this a few years back
(https://patchwork.ozlabs.org/patch/800142/) and didn't pursue it
further because at that time, it was felt that the approach might not
work for PowerVM guests, because all the present memory except RMA
gets marked as hot-pluggable by PowerVM. This discussion is not
present in the above thread, but during my private discussions with
Reza and Nathan, it was noted that making all that memory as MOVABLE
is not preferable for PowerVM guests as we might run out of memory for
kernel allocations.

Humm, this makes sense.
But with mu change, these pieces of memory only get into ZONE_MOVABLE
if the boot parameter 'movable_node' gets passed to guest kernel. 

So, even if we are unable to sort out some flag combination that work
fine for both use-cases, if PowerVM don't pass 'movable_node' as boot
parameter to kernel, it will behave just as today.

What are your thoughts on that?

Best regards,

Leonardo Bras