From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH RESEND v7 1/9] xen: vnuma topology and subop hypercalls Date: Fri, 22 Aug 2014 15:54:17 +0200 Message-ID: <1408715657.3725.182.camel@Solace.lan> References: <1408597732-21031-1-git-send-email-ufimtseva@gmail.com> <1408597732-21031-2-git-send-email-ufimtseva@gmail.com> <53F75EF7020000780002CB7E@mail.emea.novell.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7384571607934271476==" Return-path: In-Reply-To: <53F75EF7020000780002CB7E@mail.emea.novell.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: Jan Beulich Cc: keir@xen.org, Ian.Campbell@citrix.com, lccycc123@gmail.com, george.dunlap@eu.citrix.com, msw@linux.com, stefano.stabellini@eu.citrix.com, ian.jackson@eu.citrix.com, xen-devel@lists.xen.org, Elena Ufimtseva List-Id: xen-devel@lists.xenproject.org --===============7384571607934271476== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-LyxG1Fj5jCjeyHYdhTA8" --=-LyxG1Fj5jCjeyHYdhTA8 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On ven, 2014-08-22 at 14:17 +0100, Jan Beulich wrote: > > + if ( ret ) > > + return ret; > > + > > + ret =3D -EFAULT; > > + > > + if ( copy_from_guest(v->vdistance, u_vnuma->vdistance, > > + nr_vnodes * nr_vnodes) ) > > + goto vnuma_fail; > > + > > + if ( copy_from_guest(v->vmemrange, u_vnuma->vmemrange, nr_vnodes) = ) > > + goto vnuma_fail; >=20 > Isn't a single memory range per vnode rather limiting? Physical > machines frequently have at least one node with two ranges to > accommodate the hole below 4Gb. And since the interface is for > all guest kinds I'm afraid this will harm setting up guests rather > sooner than later. (I'm sorry for thinking of this only now.) >=20 This actually was one concern of mine too, during the early stage of Elena's work. I clearly remember wondering, and even asking, considering that Linux uses more ranges per node, why using only one was ok for us. Unfortunately, I OTOH forgot how that discussion ended and how we got to this point, without me or anyone else (continuing to) complaining... So, sorry from me too. :-( Let's see what Elena and others think and, after that, how big of a piece of work is to introduce support for more than one ranges (or re-introduce, as I also think I remember this to be some kind of list, during early versions of the series). Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-LyxG1Fj5jCjeyHYdhTA8 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 iEYEABECAAYFAlP3S4kACgkQk4XaBE3IOsRUzwCeMbWOFZNMep1+RRDVah9YlgRe VJsAoJHmU/yehl1d21zeV60Gnt3y67Ge =Krxm -----END PGP SIGNATURE----- --=-LyxG1Fj5jCjeyHYdhTA8-- --===============7384571607934271476== 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 --===============7384571607934271476==--