From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH RFC v2] Add SUPPORT.md Date: Tue, 26 Sep 2017 09:12:49 +0200 Message-ID: <1506409969.27663.26.camel@citrix.com> References: <20170911170159.3083-1-george.dunlap@citrix.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============4479119558310502624==" Return-path: Received: from mail6.bemta5.messagelabs.com ([195.245.231.135]) by lists.xenproject.org with esmtp (Exim 4.84_2) (envelope-from ) id 1dwk3D-0001Nj-Ij for xen-devel@lists.xenproject.org; Tue, 26 Sep 2017 07:13:03 +0000 In-Reply-To: List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Errors-To: xen-devel-bounces@lists.xen.org Sender: "Xen-devel" To: Stefano Stabellini , George Dunlap Cc: Wei Liu , Andrew Cooper , Tim Deegan , Robert VanVossen , Julien Grall , JoshWhitehead , Meng Xu , Jan Beulich , Ian Jackson , xen-devel@lists.xenproject.org List-Id: xen-devel@lists.xenproject.org --===============4479119558310502624== Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="=-eZUorqcCAJSv5Ra7/o+F" --=-eZUorqcCAJSv5Ra7/o+F Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable [Cc-list modified by removing someone and adding someone else] On Mon, 2017-09-25 at 16:10 -0700, Stefano Stabellini wrote: > On Mon, 11 Sep 2017, George Dunlap wrote: > > +### RTDS based Scheduler > > + > > +=C2=A0=C2=A0=C2=A0=C2=A0Status: Experimental > > + > > +A soft real-time CPU scheduler built to provide guaranteed CPU > > capacity to guest VMs on SMP hosts > > + > > +### ARINC653 Scheduler > > + > > +=C2=A0=C2=A0=C2=A0=C2=A0Status: Supported, Not security supported > > + > > +A periodically repeating fixed timeslice scheduler. Multicore > > support is not yet implemented. > > + > > +### Null Scheduler > > + > > +=C2=A0=C2=A0=C2=A0=C2=A0Status: Experimental > > + > > +A very simple, very static scheduling policy=C2=A0 > > +that always schedules the same vCPU(s) on the same pCPU(s).=C2=A0 > > +It is designed for maximum determinism and minimum overhead > > +on embedded platforms. >=20 > Hi all, >=20 Hey! > I have just noticed that none of the non-credit schedulers are > security > supported. Would it make sense to try to support at least one of > them? >=20 Yes, that indeed would be great. > For example, RTDS is not new and Dario is co-maintaining it. It is > currently marked as Supported in the MAINTAINERS file. Is it really > fair > to mark it as "Experimental" in SUPPORT.md? >=20 True, but there still one small missing piece in RTDS, before I'd feel comfortable about telling people "here, it's ready, use it at will", which is the work conserving mode. There are patches out for this, and they were posted before last posting date, so, in theory, they still can go in 4.10. > The Null scheduler was new when we started this discussion, but now > that > Xen 4.10 is entering code freeze, Null scheduler is not so new > anymore. > We didn't get any bug reports during the 4.10 development window. By > the > time this document is accepted and Xen 4.10 is out, Null could be a > candidate for "Supported" too. >=20 Yes, especially considering how simple it is, there should be no big issues preventing that to happen. There's one thing, though: it's not tested in OSSTest. I can actually try to have a quick look about creating a job that does that (I mean like today). The trickiest part is the need to limit the number of Dom0 vCPUs, to a number that would allow the creation and the local migration of guests (considering that the number of pCPUs of the testbox in the MA colo varies, and that we have some ARM boards with like 1 or 2 CPUs). Actually, the best candidate for gaining security support, is IMO ARINC. Code is also rather simple and "stable" (hasn't changed in the last... years!) and it's used by DornerWorks' people for some of their projects (I think?). It's also not tested in OSSTest, though, and considering how special purpose it is, I think we're not totally comfortable marking it as Sec-Supported, without feedback from the maintainers. George, Josh, Robert? Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-eZUorqcCAJSv5Ra7/o+F 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 iQIcBAABCAAGBQJZyf3xAAoJEBZCeImluHPuCwYQAINU8T2pu9iF83OZ5+C6vmWF Y1L2AAi3i1sozLcmEsnuPdzUw/GIyMcILztF56UmoqAxUMkK3ksye9Per3DoqIH6 C+ZAejUTTl1Z8OEYbREuqNQMAsZ3zqeVAfFEPo/daidoId6vsVtIuMtEXg+oFUIh xRUU54H1O4xz7w3o5lb3Cj5zxZyXQyHEf4SCkzCqzyHA+FKhSo+6TgkhWBnt9DCQ hEqVI3bedkGgbAL4zITRGwmUmSoXz+6zRn/ej/1KbgX2Gy1lEeGSu304pdqDgdMZ GmvMa/uK5/I1XZIx5NNr3NiPwWadh7NcvuIK6mfScbZ6EKW+T6EEpOYQh6fFPqdU oKSPiSpd1ntW/WNx87EM9mi9uyaFQmgdvJRIayL3mHU5EZALUomF4Ar6BxWZf9ra EWzjSny6OnUs0p1M5ww9qPAEFUFBAmZ9aE7rhVCLhKLWClvdNGweGadFcS6HbCR2 Z02PKLc3KsjS3XM2CfSOcK55VdybvBTigUXCYC5FSz+tkgDDOPAj6qOv/1LYdHOa F6GspPCAhJzZ2wtUiIEr5rd8zRJuqP2yv2hG/WjyluIrJP+4m5zYyWbFBIiaot7G 5wwH5oQdYZaCG3HgkjwJm31c0ZrHvTpsDlv2kHEqOsQGYillmLUP4wC81f5YmXUH eyxnRom+n/v5ANukSdUe =nk22 -----END PGP SIGNATURE----- --=-eZUorqcCAJSv5Ra7/o+F-- --===============4479119558310502624== Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: base64 Content-Disposition: inline X19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX19fX18KWGVuLWRldmVs IG1haWxpbmcgbGlzdApYZW4tZGV2ZWxAbGlzdHMueGVuLm9yZwpodHRwczovL2xpc3RzLnhlbi5v cmcveGVuLWRldmVsCg== --===============4479119558310502624==--