From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH v2 for Xen 4.6 4/4] xl: enabling XL to set per-VCPU parameters of a domain for RTDS scheduler Date: Tue, 9 Jun 2015 17:53:17 +0200 Message-ID: <1433865197.2403.163.camel@citrix.com> References: <1432599084-20956-1-git-send-email-chong.li@wustl.edu> <1433780473.2403.37.camel@citrix.com> <1433836901.2403.59.camel@citrix.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7318095317319021976==" Return-path: In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Chong Li Cc: Chong Li , Wei Liu , Sisu Xi , George Dunlap , xen-devel , Meng Xu , Dagaen Golomb List-Id: xen-devel@lists.xenproject.org --===============7318095317319021976== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-SgsmPU1OZke5XxprZTYI" --=-SgsmPU1OZke5XxprZTYI Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2015-06-09 at 10:12 -0500, Chong Li wrote: > On Tue, Jun 9, 2015 at 3:01 AM, Dario Faggioli > wrote: > How about making >=20 > # xl sched-rtds -d vm1 >=20 > output the per-dom parameters (of vm1), and meanwhile let > > # xl sched-rtds -d vm1 -v all >=20 > output the per-vcpu parameters (of vm1). >=20 > So, in this way, all the "per-vcpu" commands need to consistently specify= "-v". >=20 I see what you mean, but what I don't like is the distinction between per-dom and per-vcpu parameters and command... I don't think it make sense (see below). > > So, IIRC, in patch 3 you are just not touching > > libxl_domain_sched_params_get(), nor sched_rtds_domain_get() and > > (perhaps in another patch) xc_sched_rtds_domain_get(). What I'm asking > > is, what does it mean "users who only do per-dom settings"? What happen= s > > if I, for instance, do a bunch of: > > > > libxl_vcpu_sched_params_set(...) > > > > for various vcpus, each one with different parameters, and then call: > > > > libxl_domain_sched_params_get(...) > > > > Have you tested this case? What's the output? >=20 > I described this use case in the cover letter. >=20 Ok, yes, now I remember seeing it, and wanting to comment. Then, because of the bad threading of the series, the cover letter is somewhere lost in my xen-devel folder, and I forgot to revisit it when reviewing the single patches. It's certainly my fault, but that's one of the many reasons why the proper threading is important. > "This command should only be used when all vcpus of a domain have the > same parameters, otherwise the output > is pointless. The period and budget shown in the output are equal to > the parameters of the first > VCPU of each domain." >=20 > Or, I think we can just output a warning message in this case. >=20 Neither would be optimal, IMO. If I set the parameters of the vcpus of a VM, then my shift finishes and I leave, how does the sysadmin that does the next shift (or even me, after 1 month) whether I gave to all the vcpus the same parameters, and hence whether the output of `xl sched-rtds -o' (or whatever) can be trusted? What do you mean with "output a warning message"? Do you mean printing a warning if someone tries to retrieve domain scheduling parameters of the RTDS scheduling? Or do you mean print a warning if the vcpus have different parameters? As said, I don't like much this option either, but doing the former may be the only option we have (the latter looks just silly). Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-SgsmPU1OZke5XxprZTYI 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 iEYEABECAAYFAlV3C+0ACgkQk4XaBE3IOsSE+wCdEIQxcDhG4whgRWJLvReOHA8L iscAoKqF40OWHztPtzVnExbcXoOlvAkk =LPQm -----END PGP SIGNATURE----- --=-SgsmPU1OZke5XxprZTYI-- --===============7318095317319021976== 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 --===============7318095317319021976==--