From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH for 4.5 v4 1/4] xen: add real time scheduler rtds Date: Mon, 22 Sep 2014 19:13:17 +0200 Message-ID: <1411405997.4116.13.camel@Solace.lan> References: <1411251228-2093-1-git-send-email-mengxu@cis.upenn.edu> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============6284118185115674219==" Return-path: In-Reply-To: <1411251228-2093-1-git-send-email-mengxu@cis.upenn.edu> List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: Meng Xu Cc: ian.campbell@citrix.com, xisisu@gmail.com, stefano.stabellini@eu.citrix.com, george.dunlap@eu.citrix.com, lu@cse.wustl.edu, ian.jackson@eu.citrix.com, xen-devel@lists.xen.org, ptxlinh@gmail.com, xumengpanda@gmail.com, JBeulich@suse.com, chaowang@wustl.edu, lichong659@gmail.com, dgolomb@seas.upenn.edu List-Id: xen-devel@lists.xenproject.org --===============6284118185115674219== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-u7Gr6ulMVrYEwietMCZo" --=-u7Gr6ulMVrYEwietMCZo Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On sab, 2014-09-20 at 18:13 -0400, Meng Xu wrote: > This scheduler follows the Preemptive Global Earliest Deadline First > (EDF) theory in real-time field. > At any scheduling point, the VCPU with earlier deadline has higher > priority. The scheduler always picks the highest priority VCPU to run on = a > feasible PCPU. > A PCPU is feasible if the VCPU can run on this PCPU and (the PCPU is > idle or has a lower-priority VCPU running on it.) >=20 > Each VCPU has a dedicated period and budget. > The deadline of a VCPU is at the end of each period; > A VCPU has its budget replenished at the beginning of each period; > While scheduled, a VCPU burns its budget. > The VCPU needs to finish its budget before its deadline in each period; > The VCPU discards its unused budget at the end of each period. > If a VCPU runs out of budget in a period, it has to wait until next perio= d. >=20 > Each VCPU is implemented as a deferable server. > When a VCPU has a task running on it, its budget is continuously burned; > When a VCPU has no task but with budget left, its budget is preserved. >=20 > Queue scheme: > A global runqueue and a global depletedq for each CPU pool. > The runqueue holds all runnable VCPUs with budget and sorted by deadline; > The depletedq holds all VCPUs without budget and unsorted. >=20 > Note: cpumask and cpupool is supported. >=20 > This is an experimental scheduler. >=20 > Signed-off-by: Meng Xu > Signed-off-by: Sisu Xi > Acked-by: Jan Beulich > Reviewed-and-Tested-by: Dario Faggioli 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) --=-u7Gr6ulMVrYEwietMCZo 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 iEYEABECAAYFAlQgWK0ACgkQk4XaBE3IOsTgMwCfbfVIkb5rgjoITQm7ru/gnjvb nXIAnjOua6DDntnK0Iqo5Rm74rlvpiZi =wbP2 -----END PGP SIGNATURE----- --=-u7Gr6ulMVrYEwietMCZo-- --===============6284118185115674219== 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 --===============6284118185115674219==--