Re: WTH is going on with memory hotplug sysf interface (was: Re: [RFC PATCH] mm, hotplug: get rid of auto_online_blocks)

From: Andi Kleen
Date: Mon Mar 13 2017 - 19:16:15 EST

> and ARCH_SPARSEMEM_DEFAULT is enabeld on 64b. So I guess whatever was
> the reason to add this code back in 2006 is not true anymore. So I am
> really wondering. Do we absolutely need to assign pages which are not
> onlined yet to the ZONE_NORMAL unconditionally? Why cannot we put them
> out of any zone and wait for memory online operation to put them where
> requested?

I don't remember any specific reason. May have just been simplification.
Should be fine to use any zone.