From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [RFC PATCH 0/7] Intel Cache Monitoring: Current Status and Future Opportunities Date: Wed, 8 Apr 2015 08:23:11 +0000 Message-ID: <1428481389.5671.98.camel@citrix.com> References: <20150404020423.22875.23590.stgit@Solace.station> <5523B0FB.8020509@citrix.com> <1428412199.5671.94.camel@citrix.com> <20150408055916.GF3404@pengc-linux.bj.intel.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7887755361639556685==" Return-path: In-Reply-To: <20150408055916.GF3404@pengc-linux.bj.intel.com> Content-Language: en-US List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: "chao.p.peng@linux.intel.com" Cc: Wei Liu , Ian Campbell , Andrew Cooper , George Dunlap , "xen-devel@lists.xen.org" , "JBeulich@suse.com" List-Id: xen-devel@lists.xenproject.org --===============7887755361639556685== Content-Language: en-US Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-G3Ap4XYH6VeJQ6jTaLZG" --=-G3Ap4XYH6VeJQ6jTaLZG Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Wed, 2015-04-08 at 13:59 +0800, Chao Peng wrote: > > Mostly, I was curious to learn why that is not reflected in the current > > implementation, i.e., whether there are any reasons why we should not > > take advantage of per-socketness of RMIDs, as reported by SDM, as that > > can greatly help mitigating RMID shortage in the per-CPU/core/socket > > configuration (in general, actually, but it's per-cpu that I'm > > interested in). >=20 > Andrew is right, RMID is a per-socket property. One reason it's not used > in current implementation, I think, is the fact that max_rmid is > normally the same among sockets, though they can be different in theory. > So the same RMID is targeted for all the sockets. But per-socketness of > RMIDs can be used anyway.=20 >=20 Yeah, but rather than to the maximum number of available RMIDs, what I'm much interested in is whether I can use _the_ _same_ RMID for different cores, if they belong to different sockets. AFAIUI, it is possible, is that correct? > > All true. And in fact, how and how frequent data should be gathered > > remains to be decided (as said in the document). I was thinking more to > > some periodic sampling, rather than to throw handfuls of rdmsr/wrmsr > > against the code that makes scheduling decisions! :-D >=20 > Due to current hardware limitations and in the case of scheduling improve= ment, > periodic sampling sounds a feasible direction to me. >=20 Good to know, thanks. Regards, Dario --=-G3Ap4XYH6VeJQ6jTaLZG 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 iEYEABECAAYFAlUk5W0ACgkQk4XaBE3IOsRbAQCdExTVb3SkDENTKp3F8HatzGjn SQUAoIZf2e0d5bfQCxSCztTCl6sXxyvB =vIXu -----END PGP SIGNATURE----- --=-G3Ap4XYH6VeJQ6jTaLZG-- --===============7887755361639556685== 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 --===============7887755361639556685==--