From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH 08 of 10 v3] libxl: enable automatic placement of guests on NUMA nodes Date: Fri, 06 Jul 2012 15:52:53 +0200 Message-ID: <1341582773.15708.42.camel@Abyss> References: <7087d3622ee2051654c9.1341418687@Solace> <1341572142.32747.20.camel@zakaz.uk.xensource.com> <1341579810.15708.20.camel@Abyss> <1341580905.32747.41.camel@zakaz.uk.xensource.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============1569541301864229741==" Return-path: In-Reply-To: <1341580905.32747.41.camel@zakaz.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: Ian Campbell Cc: Andre Przywara , Stefano Stabellini , George Dunlap , Juergen Gross , Ian Jackson , "xen-devel@lists.xen.org" , Roger Pau Monne List-Id: xen-devel@lists.xenproject.org --===============1569541301864229741== Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-GouTf34h0RhzHIrTfmC0" --=-GouTf34h0RhzHIrTfmC0 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2012-07-06 at 14:21 +0100, Ian Campbell wrote:=20 > > Ok, I see. What about something like the below: > >=20 > > "However, if the amount of free memory of two candidates is very > > similar, we look at how many domains are assigned to each candidate, an= d > > take the one that has fewer of them." >=20 > Looks good, thanks. >=20 Ok. > Is it still "very similar" now that it is a total order or is it > actually a strict equality now? (or an equality down to the precision of > a float...) >=20 It is, at least according to me. In fact, if the normalized difference between the amount of free memory of two candidates is 0.1 (i.e., candidates are "very similar") and the difference in number of domains is -0.5 (one has half the domains the other does) we get 3*0.1-0.5=3D-0.2 =3D=3D> the number of domains is important. OTOH, a normalized difference of 0.2 in the amount of free memory (i.e., candidates are no longer "very similar") is enough to prevent the same difference in number of domains from subverting the sign of the comparison. It of course depends on how much details we want to go in in this kind of documentation. Given there's no way neither an application developer nor an user could change/affect the parameters controlling the heuristics, I think what we have there is just fine. Did I persuade you? :-P Thanks and Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://retis.sssup.it/people/faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-GouTf34h0RhzHIrTfmC0 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 v1.4.12 (GNU/Linux) iEYEABECAAYFAk/27bUACgkQk4XaBE3IOsRyDgCfRU+jByE5xa6spr36VaqigejG /c8An30ITewDzd2doWJbIKiu8Ui6cduv =kNYu -----END PGP SIGNATURE----- --=-GouTf34h0RhzHIrTfmC0-- --===============1569541301864229741== 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 --===============1569541301864229741==--