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

[Michal Hocko]

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

-- 
Michal Hocko
SUSE Labs