From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH v1 1/4] xen: add real time scheduler rt Date: Fri, 5 Sep 2014 11:46:26 +0200 Message-ID: <1409910386.2673.265.camel@Solace.lan> References: <1408921125-21470-1-git-send-email-mengxu@cis.upenn.edu> <1408921125-21470-2-git-send-email-mengxu@cis.upenn.edu> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============4612461500563773249==" 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: George Dunlap Cc: Ian Campbell , Sisu Xi , Stefano Stabellini , Ian Jackson , "xen-devel@lists.xen.org" , Meng Xu , Meng Xu , Jan Beulich , chaowang@wustl.edu, Chong Li , dgolomb@seas.upenn.edu List-Id: xen-devel@lists.xenproject.org --===============4612461500563773249== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-zg14hsVvoc+XmjtMUHxW" --=-zg14hsVvoc+XmjtMUHxW Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On mer, 2014-09-03 at 14:40 +0100, George Dunlap wrote: > On Sun, Aug 24, 2014 at 11:58 PM, Meng Xu wrote: > > This scheduler follows the pre-emptive Global EDF theory in real-time f= ield. > > Each VCPU can have a dedicated period and budget. > > While scheduled, a VCPU burns its budget. > > A VCPU has its budget replenished at the beginning of each of its perio= ds; > > The VCPU discards its unused budget at the end of each of its periods. > > If a VCPU runs out of budget in a period, it has to wait until next per= iod. > > The mechanism of how to burn a VCPU's budget depends on the server mech= anism > > implemented for each VCPU. > > > > Server mechanism: a VCPU is implemented as a deferable server. > > When a VCPU is scheduled to execute on a PCPU, its budget is continuous= ly > > burned. > > > > Priority scheme: Preemptive Global Earliest Deadline First (gEDF). > > At any scheduling point, the VCPU with earliest deadline has highest > > priority. > > > > Queue scheme: A global Runqueue for each CPU pool. > > The Runqueue holds all runnable VCPUs. > > VCPUs in the Runqueue are divided into two parts: with and without budg= et. > > At each part, VCPUs are sorted based on gEDF priority scheme. > > > > Scheduling quantum: 1 ms; > > > > Note: cpumask and cpupool is supported. > > > > This is still in the development phase. >=20 > You should probably take this out now that you've removed the RFC. :-) >=20 Should him? I mean, AFAIUI, we are accepting (well, at least, that's the plan :-) ) the scheduler in an 'experimental' status. When we merged ARM support for the first time, I remember there were some similar claims around the code and docs (it was API/ABI/something stability at the time, I think), and the same, IIRC, for PVH. Credit2 still warns his users like this, on boot: printk("Initializing Credit2 scheduler\n" \ " WARNING: This is experimental software in development.\n" \ " Use at your own risk.\n"); So, probably "still in the development phase" may be a bit strong, but I'd be inclined have something like that somewhere. Thoughts? Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-zg14hsVvoc+XmjtMUHxW 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 iEYEABECAAYFAlQJhnIACgkQk4XaBE3IOsTaHACcDNyBDR3e+N5MLME+7qvGGHjf w80AoI/HnlIHGORuyOclfORFe8Fxyu6M =s5mk -----END PGP SIGNATURE----- --=-zg14hsVvoc+XmjtMUHxW-- --===============4612461500563773249== 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 --===============4612461500563773249==--