Re: [RFC PATCH] mm, memory_hotplug: support movable_node for hotplugable nodes

[Reza Arbab]

On Thu, Jun 01, 2017 at 05:52:31PM +0200, Michal Hocko wrote:
> On Thu 01-06-17 10:47:46, Reza Arbab wrote:
> > On Thu, Jun 01, 2017 at 05:38:38PM +0200, Michal Hocko wrote:
> > >On Thu 01-06-17 10:19:36, Reza Arbab wrote:
> > >>The x86 SRAT (or the dt, on other platforms) can describe memory as
> > >>hotpluggable. See memblock_mark_hotplug(). That's only for memory present at
> > >>boot, though.
> > >
> > >Yes but lose that information after the memblock is gone and numa fully
> > >initialized. Or can we reconstruct that somehow?
> >
> > I'm not sure you'd have to. At boot time, those markings are used to
> > determine the initial boundaries of ZONE_MOVABLE. So if you removed these
> > memblocks, then readded them, they would still be in ZONE_MOVABLE.
>
> Yes but that already works like that. I am nore interested in the case
> when the node goes away and it is added again. echo online > ... would
> result in a non-movable memory and that is the inconsistency I tried to
> call out in the changelog

My bad. Should have read closer.

--
Reza Arbab