linux-kernel - Re: [PATCH v7 2/4] virtio_balloon: introduce migration primitives to balloon pages

lists.openwall.net		lists / announce owl-users owl-dev john-users john-dev passwdqc-users yescrypt popa3d-users / oss-security kernel-hardening musl sabotage tlsify passwords / crypt-dev xvendor / Bugtraq Full-Disclosure linux-kernel linux-netdev linux-ext4 linux-hardening linux-cve-announce PHC
Open Source and information security mailing list archives

Hash Suite: Windows password security audit tool. GUI, reports in PDF.

[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]

Message-ID: <87mx1o3j5y.fsf@rustcorp.com.au>
Date:	Tue, 21 Aug 2012 15:01:37 +0930
From:	Rusty Russell <rusty@...tcorp.com.au>
To:	"Michael S. Tsirkin" <mst@...hat.com>, Mel Gorman <mel@....ul.ie>
Cc:	Rafael Aquini <aquini@...hat.com>, linux-mm@...ck.org,
	linux-kernel@...r.kernel.org,
	virtualization@...ts.linux-foundation.org,
	Rik van Riel <riel@...hat.com>,
	Andi Kleen <andi@...stfloor.org>,
	Andrew Morton <akpm@...ux-foundation.org>,
	Konrad Rzeszutek Wilk <konrad.wilk@...cle.com>,
	Minchan Kim <minchan@...nel.org>
Subject: Re: [PATCH v7 2/4] virtio_balloon: introduce migration primitives to balloon pages

On Wed, 15 Aug 2012 14:28:51 +0300, "Michael S. Tsirkin" <mst@...hat.com> wrote:
> On Wed, Aug 15, 2012 at 12:16:51PM +0100, Mel Gorman wrote:
> > I was thinking of exactly that page->mapping == balloon_mapping check. As I
> > do not know how many active balloon drivers there might be I cannot guess
> > in advance how much of a scalability problem it will be.
> 
> Not at all sure multiple drivers are worth supporting, but multiple
> *devices* is I think worth supporting, if for no other reason than that
> they can work today. For that, we need a device pointer which Rafael
> wants to put into the mapping, this means multiple balloon mappings.

Rafael, please make sure that the balloon driver fails on the second and
subsequent balloon devices.

Michael, we only allow multiple balloon devices because it fell out of
the implementation.  If it causes us even the slightest issue, we should
not support it.  It's not a sensible setup.

Cheers,
Rusty.

--
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to majordomo@...r.kernel.org
More majordomo info at  http://vger.kernel.org/majordomo-info.html
Please read the FAQ at  http://www.tux.org/lkml/