Subject: Re: [RFC 0/3] Prototype PAPR hash page table resizing (guest side)

From: David Gibson <[email-masked]>
Date: Thu, 24 Dec 2015 21:38:44 +1100

On Thu, Dec 24, 2015 at 02:52:53PM +0530, Anshuman Khandual wrote:
> On 12/22/2015 10:44 AM, David Gibson wrote:
> > I've discussed with Paul and Ben previously the possibility of
> > extending PAPR to allow changing the size of a running guest's hash
> > page table (HPT).  This would allow for much more flexible memory
> > hotplug, since the HPT wouldn't have to be sized in advance for the
> > maximum possible memory size of the guest.
> 
> Does it include reducing the size of HPT as well ?

It does, but that could fail with H_PTEG_FULL if there's a collision
between bolted entries in the reduced table.

-- 
David Gibson			| I'll have my music baroque, and my code
david AT gibson.dropbear.id.au	| minimalist, thank you.  NOT _the_ _other_
				| _way_ _around_!
http://www.ozlabs.org/~dgibson