Re: [PATCH RFC 7/8] mm: allow to control onlining/offlining of memory by a driver

From: Michal Hocko
Date: Fri Apr 13 2018 - 11:59:54 EST


On Fri 13-04-18 15:33:28, David Hildenbrand wrote:
> Some devices (esp. paravirtualized) might want to control
> - when to online/offline a memory block
> - how to online memory (MOVABLE/NORMAL)
> - in which granularity to online/offline memory
>
> So let's add a new flag "driver_managed" and disallow to change the
> state by user space. Device onlining/offlining will still work, however
> the memory will not be actually onlined/offlined. That has to be handled
> by the device driver that owns the memory.

Is there any reason to create the memblock sysfs interface to this
memory at all? ZONE_DEVICE mem hotplug users currently do not do that
and manage the memory themselves. It seems you want to achieve the same
thing, no?
--
Michal Hocko
SUSE Labs