Re: [PATCH v5 00/10] mm: Sub-section memory hotplug support

From: Michal Hocko
Date: Thu Mar 28 2019 - 10:16:37 EST


On Thu 28-03-19 14:38:15, David Hildenbrand wrote:
> On 27.03.19 17:13, Michal Hocko wrote:
[...]
> > People are asking for a smaller memory hotplug granularity for other
> > usecases (e.g. memory ballooning into VMs) which are quite dubious to
> > be honest and not really worth all the code rework. If we are talking
> > about something that can be worked around elsewhere then it is preferred
> > because the code base is not in an excellent shape and putting more on
> > top is just going to cause more headaches.
>
> At least for virtio-mem, it will be handled similar to xen-balloon and
> hyper-v balloon, where whole actions are added and some parts are kept
> "soft-offline". But there, one device "owns" the complete section, it
> does not overlap with other devices. One section only has one owner.

This is exactly what I meant by handing at a higher level.

--
Michal Hocko
SUSE Labs