From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [BUG] XEN-4.8-rc2 sched-rtds does not accept settings Date: Tue, 18 Oct 2016 23:49:23 +0200 Message-ID: <1476827363.6533.20.camel@citrix.com> References: <335048278.50.1476741321851.JavaMail.zimbra@homie.homelinux.net> <20161018105114.GC23651@citrix.com> <1739067370.34.1476816748999.JavaMail.zimbra@homie.homelinux.net> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============5919446485619480549==" Return-path: In-Reply-To: <1739067370.34.1476816748999.JavaMail.zimbra@homie.homelinux.net> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Juergen Schinker , Meng Xu Cc: Wei Liu , xen-devel List-Id: xen-devel@lists.xenproject.org --===============5919446485619480549== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="=-n7Y4HhNEuDrkavi+ohLO" --=-n7Y4HhNEuDrkavi+ohLO Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2016-10-18 at 19:52 +0100, Juergen Schinker wrote: > > On Tue, Oct 18, 2016 at 6:51 AM, Wei Liu > > wrote: > > >=C2=A0 > > Another thing is that the current RTDS scheduler will only allocate > > the amount of resource to the VCPU you set.=C2=A0=C2=A0Since you set p= eriod > > and > > budget to be 20000 and 8000, you only get 40% CPU resource. (We > > won't > > get more resource than you set under the current RTDS.) > >=20 > what is the min max? >=20 Not sure what you mean, but I think the answer is that it's a max. I.e., a vcpu will never get more than 8ms every 20ms, which means it will never get more than 40% CPU time. But if it asks less than that, it will (of course!) get less). It can also be seen as a min, but that depends on the system configuration. So far, there is nothing that prevents you to assign 40% of CPU time to 10 vCPUs. This means you've allocated 400% CPUs. If you have, say, only 2 CPUs, you're overbooking, and there's no way everyone will get all of what they ask for. How graceful the performance degradation is, I'll leave it to Meng (I recall EDF does that in a very nice manner, but I can't remember whether that is the case in the actual algorithm RTDS is based on). But again, I'm not sure whether this is what you were asking. =C2=A0 > well I just wanted to test it and see how it performs and don't have > a special need for this scheduler >=20 Ah, ok. When doing such experiments, consider using cpupools. They come in very handy, as you can dynamically assign a scheduler to a set of CPUs, move domains there, and test and check whatever you want, without having to reboot with different parameters, etc. > except shutting up loudmouthes who say you can not assure > min=C2=A0=C2=A0resources to a domain :-) >=20 Right, this is a very good purpose... Let us know if you need help on it! :-P Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-n7Y4HhNEuDrkavi+ohLO 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 iQIcBAABCAAGBQJYBpjjAAoJEBZCeImluHPuCroQAIfRjFBKAEjGbBdRRkStH/LR TMomfEQhb7/o06TkYoO4tKk3tWLXHSQTuN+1FHwCiq0ARXnfLitj54XfyEoZaTDW bpt/HHgB3ylSpDtPq7Mqq2bpSM8ot+lL0hxvmvZFe8aQ0Mxi60t/EssXE2ssNRDl yWElSqz4SgGAl3BjO6n0FSr5gUgDNwwW7CK/3wxlIv/ghN3qW+NUEApb5bGqTDMF kxlkE5otzSvFau3aUoeYKl/n2AQMzysZm7JHu99awmGPVi7rl2VSx60ccAffV8Oh J4T2GVVGIWmtPCPrRRUTmwpQE+8BsOvDWcjJZISYAtynaaplkeaBevOl9NyWadO5 SNjoA5GGSpCLMwlvC81Jg5owVzT3oCd8BW8eTqjC0EAFrJuKXwf4luhlc18/7bEJ wrjp2DDZRXY2Xi/ZnAwQKqtBHoU1aS+piT+YN2TwLfW6wpMX6zM6bEjMOZ5iXAAn MgVrCZT9r7sPvzotOBUBC2tHwAjALeUN5NZelFiMJo8T50DFg2Rc+g+b2Z/x1Eqi upMJKH6SC9DRYSodzWTnmo2icc8Z5K0vYofY8vejN6P0BJ0EOKAu8GZnNa9GzfeS rNw7ec5l2giVChizHpPk97m0ZnynmwX9KBljWNnHrYxOkayzFXDx/p3ePlSSfE9Y S200IISlyPQ6qJopVl/F =e0gr -----END PGP SIGNATURE----- --=-n7Y4HhNEuDrkavi+ohLO-- --===============5919446485619480549== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVuLm9yZwpodHRwczovL2xpc3RzLnhlbi5v cmcveGVuLWRldmVsCg== --===============5919446485619480549==--