From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [DOC RFC] Heterogeneous Multi Processing Support in Xen Date: Thu, 8 Dec 2016 11:27:05 +0100 Message-ID: <1481192825.3445.157.camel@citrix.com> References: <1481135379.3445.142.camel@citrix.com> <3f9a7da1-7c05-e082-99d2-302dbeee61b9@suse.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============4070623808743404924==" Return-path: In-Reply-To: <3f9a7da1-7c05-e082-99d2-302dbeee61b9@suse.com> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Juergen Gross , Xen Devel Cc: Peng Fan , Stefano Stabellini , George Dunlap , Andrew Cooper , anastassios.nanos@onapp.com, Jan Beulich , Peng Fan List-Id: xen-devel@lists.xenproject.org --===============4070623808743404924== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="=-TCoHM0wle/jGJyt24YlI" --=-TCoHM0wle/jGJyt24YlI Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2016-12-08 at 07:12 +0100, Juergen Gross wrote: > On 07/12/16 19:29, Dario Faggioli wrote: > >=20 > > Setting and getting the CPU class of a vCPU will happen via two new > > hypercalls: > >=20 > > * `XEN_DOMCTL_setvcpuclass` > > * `XEN_DOMCTL_setvcpuclass` >=20 > XEN_DOMCTL_getvcpuclass >=20 Oops, thanks. > > ### Phase 2 > >=20 > > Inside Xen, the various schedulers will be modified to deal > > internally with > > the fact that vCPUs can only run on pCPUs from the class(es) they > > are > > associated with. This allows for more efficient implementation, and > > paves > > the way for enabling more intelligent logic (e.g., for minimizing > > power > > consumption) in *phase 3*. > >=20 > Any idea how to avoid problems in the schedulers related to vcpus > with > different weights?=20 > Sure: use Credit2! :-P And I'm not joking (not entirely, at least), as the alternative is to re-engineer significantly the algorithm inside Credit, which I'm not sure is doable or worthwhile, especially considering we have alternatives. > Remember, weights and pinning don't go well together, > that was the main reason for inventing cpupools. You should at least > name that problem.=20 > Yes, that's true. I will add a paragraph about it. Thanks and Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-TCoHM0wle/jGJyt24YlI 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 iQIcBAABCAAGBQJYSTV6AAoJEBZCeImluHPuTCUQALQyqzElTyKHwZrtfLoFRulj p/AU5CBJ9Zgml4ygxahrZeyHq5Ta4d3NG0ll5Xz+4LeMSPbJ/6KjavQOKovELyD1 DfspATdvBvGfEdUXAL2zFjOv5TZ2j6xeV5+Ef6NRVDXkscFISwbGNf0Mans6ml58 Z2ltFEeZGviyzNs8TFzicwm83k1cnkkDeEv+9OoryjHfDy+9o80rY/hoHNMU3nhD HOGabuQEeNA3n2BkCuv98vbZA+7FQ7hbLMsIGIz/6aLQF2+1qAnI5sLC8iAO/O7/ kG+fE0C0TVmddadqjKcnGiFspXD6McBAoSDb+YtjSsC58q6aeRF7XyFcvphUbWxw yl6T3OJfAilrrkU/+MqlMoNqsoJ8YZqRtXLhP5kYp25Eg5NPl+S+KhegU515glHD Cvj7nViXrDjGZZO2Fei7+i8cwKTpf6l/sXiVOtlSB6zjrP96cqEZWU/G0106/g2m jXblWGlrCK4ksw1zTTiyZuoj9RYHZEAF1L0ArMfTdxyeWd+o1MK9b7ZR4LUiHKmB trjn0SH1AZafowmAVZOoS1tZ+4Bi9c9gEQdTZI5g5XOFlJl5Crnj4lrmSg+bHTwU okGAYCzH7lrohM/GrUZYG+7HAVQLuqfeiYi8h+BKdYUQbJkBbI5XXm9yECJE8s92 /THGLreS9OSAqZ4TD4sL =Jg6B -----END PGP SIGNATURE----- --=-TCoHM0wle/jGJyt24YlI-- --===============4070623808743404924== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVuLm9yZwpodHRwczovL2xpc3RzLnhlbi5v cmcveGVuLWRldmVsCg== --===============4070623808743404924==--