From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH for-4.5] xen: vnuma: expose vnode_to_pnode to guest Date: Mon, 10 Nov 2014 12:59:02 +0100 Message-ID: <1415620742.3717.39.camel@Abyss> References: <1415475807-8699-1-git-send-email-wei.liu2@citrix.com> <546091A40200007800045E86@mail.emea.novell.com> <20141110100016.GA17065@zion.uk.xensource.com> <1415616688.3717.16.camel@Abyss> <20141110110936.GA28360@zion.uk.xensource.com> <54609FC4.3010101@citrix.com> <20141110112751.GB28360@zion.uk.xensource.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============5974966226070142037==" Return-path: In-Reply-To: <20141110112751.GB28360@zion.uk.xensource.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Wei Liu Cc: Elena Ufimtseva , David Vrabel , Jan Beulich , xen-devel@lists.xen.org List-Id: xen-devel@lists.xenproject.org --===============5974966226070142037== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-2Th3vZBsvGKWRxOmGNX2" --=-2Th3vZBsvGKWRxOmGNX2 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2014-11-10 at 11:27 +0000, Wei Liu wrote: > On Mon, Nov 10, 2014 at 11:21:40AM +0000, David Vrabel wrote: > > On 10/11/14 11:09, Wei Liu wrote: > > >=20 > > > 3. Don't expose anything, everything happens automagically without gu= est > > > knowing anything. > >=20 > > This. The vnode to pnode mapping can change on a save/restore. >=20 > I don't think this is the most decisive reasoning of this issue. The > other two options can also deal with this -- just retrieve the > up-to-date versions after migration. >=20 IMO, what's needed is an "on demand" "translation service". The guest should not store the result of such translation and rely on it. The opposite, actually: when ballooning up (i.e., the only legittimate use case of this "service" I can think of right now), it should be possible to let the hypervisor know from what physical NUMA node we want a page, basing on which vnode such page belongs to. This is probably another argument for not using option 1, and for going for 3, if possible, or with something different, if not. Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-2Th3vZBsvGKWRxOmGNX2 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iEYEABECAAYFAlRgqIYACgkQk4XaBE3IOsS4YwCdEtNXzrI7jgghSzrb8Z9v3JqW DR8AoKNld9MfY1oz1yolOejaAJc59PwH =iV2R -----END PGP SIGNATURE----- --=-2Th3vZBsvGKWRxOmGNX2-- --===============5974966226070142037== Content-Type: text/plain; charset="us-ascii" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Content-Disposition: inline _______________________________________________ Xen-devel mailing list Xen-devel@lists.xen.org http://lists.xen.org/xen-devel --===============5974966226070142037==--