Re: [PATCH 0/5] Swap Migration V5: Overview

[Kamezawa Hiroyuki <kamezawa.hiroyu@jp.fujitsu.com>]

Hirokazu Takahashi wrote:
> Hi Christoph,
> I've read the archive of lhms-devel.
> You're going to take in most of the original migration code
> except for some tricks to migrate pages which are hard to move.
> I think this is what you said the complexity, which you
> want to remove forever.
> 
> I have to explain that this complexity came from making the code
> guarantee to be able to migrate any pages. So the code is designed:
>   - to migrate heavily accessed pages.
>   - to migrate pages without backing-store.
>   - to migrate pages without I/O's.
>   - to migrate pages of which status may be changed during the migration
>     correctly.
> 
> This have to be implemented if the hotplug memory use it.
yes.

> It seems to become a reinvention of the wheel to me.
> 
Christoph, I think you should make it clear the advantage of your code
to the -mhp tree's. I think we can add migrate_page_to() easily to the
-mhp tree's as Takahashi said.

BTW, could you explain what is done and what is not in your patch set ?

-- Kame