Re: [PATCH 1/2] mem-hotplug: use GFP_HIGHUSER_MOVABLE in, alloc_migrate_target()

[David Rientjes]

On Tue, 19 Jul 2016, Xishi Qiu wrote:

> Memory offline could happen on both movable zone and non-movable zone, and we
> can offline the whole node if the zone is movable_zone(the node only has one
> movable_zone), and if the zone is normal_zone, we cannot offline the whole node,
> because some kernel memory can't be migrated.
> 
> So how about change alloc_migrate_target() to alloc memory from the next node
> with GFP_HIGHUSER_MOVABLE, if the offline zone is movable_zone.
> 

I think sharing alloc_migrate_target as a migration callback may not be 
worth it; CMA and memory offline are distinct usecases and probably 
deserve their own callbacks.