From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: Load calculation refresh in credit2 (was in Re: Questions about the use of idle_vcpu[]) Date: Tue, 19 Jan 2016 10:23:35 +0100 Message-ID: <1453195415.11427.119.camel@citrix.com> References: <569845B7.2060207@seas.upenn.edu> <1453114800.11427.78.camel@citrix.com> <1453121249.11427.83.camel@citrix.com> <569CF2B8.9020406@citrix.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============3838088102202725708==" Return-path: In-Reply-To: <569CF2B8.9020406@citrix.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: George Dunlap , George Dunlap Cc: Tianyang Chen , Meng Xu , "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org --===============3838088102202725708== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-iAz8QGJ7TLXMtHyZkUJ4" --=-iAz8QGJ7TLXMtHyZkUJ4 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2016-01-18 at 14:12 +0000, George Dunlap wrote: > [Changing the title to align with the current topic] >=C2=A0 > Load balancing only happens on a reset event; and the frequency of > reset > events will be CREDIT_INIT / (% utilization); so for a system at 1% > utilization that would be once every second.=C2=A0=C2=A0Is that the kind = of > number > you were seeing?=C2=A0=C2=A0Or were you actually seeing idle runqueues no= t > having > anything pushed to them *during* a balance for some reason? >=20 As I said, I need to recheck... but yes, this could be the cause of my "issue". In fact, since I was reading the load from the toolstack (that was one of the purposes of the whole thing), it's quite likely that I was seeing non-updated values because the load balance hadn't run since a while. I'll keep this in mind when revisiting that work, and try to cook a patch that avoid setting the timer when the idle vcpu is returned, and see how it goes. Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-iAz8QGJ7TLXMtHyZkUJ4 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 iEYEABECAAYFAlaeAJcACgkQk4XaBE3IOsQTXACeO8XaQMJaVZVlK0M/fN4pGCAg Oc8An2cTvx83hhdP3LTeSuUKRd2dFGJI =20AE -----END PGP SIGNATURE----- --=-iAz8QGJ7TLXMtHyZkUJ4-- --===============3838088102202725708== 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 --===============3838088102202725708==--