Subject: Re: [PATCH 03/15] [PS3] Add region 1 memory early

From: Geoff Levand <[email-masked]>
Date: Thu, 4 Aug 2011 08:57:56 -0700

Hi Hector,

On 08/03/2011 05:08 PM, Hector Martin wrote:
> On 08/04/2011 12:32 AM, Geoff Levand wrote:
>> We need an explanation of this change.

Sorry for such a terse request.  What I meant was that
this is a significant change to how high mem is managed,
so the patch needs a comment explaining the change.

> I actually have a hard time understanding the reason for the existing
> behavior of hot-adding memory halfway through the boot process. Maybe
> you can shed some light on this?

LV1 was intended to be a generic hypervisor for the Cell
processor.  It was imagined that it could be used on machines
which could be running many lpars.  Around the same time I
was doing the high mem support the hot plug memory support was
being developed.  I thought at some point there would be
hot-unplug, which could be used to move memory between lpars.

At the present time this change make sense, since it is simpler
and more flexible.

-Geoff