From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [RFC PATCH v2 0/7] Repurpose SEDF Scheduler for Real-time Use Date: Fri, 11 Jul 2014 15:35:49 +0200 Message-ID: <1405085749.29306.405.camel@Solace> References: <1404939348-4926-1-git-send-email-josh.whitehead@dornerworks.com> <1405003438.26155.12.camel@kazak.uk.xensource.com> <1405054902.29306.224.camel@Solace> <1405077340.15107.5.camel@kazak.uk.xensource.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============2972469066276573664==" Return-path: In-Reply-To: <1405077340.15107.5.camel@kazak.uk.xensource.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: Ian Campbell Cc: Stefano Stabellini , George Dunlap , Ian Jackson , Robert VanVossen , Xen-devel , Nathan Studer , Josh Whitehead List-Id: xen-devel@lists.xenproject.org --===============2972469066276573664== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-cnXiA3VY4h0B9WJgMZEh" --=-cnXiA3VY4h0B9WJgMZEh Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On ven, 2014-07-11 at 12:15 +0100, Ian Campbell wrote: > On Fri, 2014-07-11 at 07:01 +0200, Dario Faggioli wrote: > > *** Short (well, sort of!) Answer *** > > Personally, I would prefer to keep SEDF alive at least for a few > > versions >=20 > As it currently is or somehow partially modified? >=20 As it is we can leave it in place for how long we want, I guess, but it's useless. My point was that, in a partially modified form, it can serve as a transition to a nnew scheduler or even live "forever". Anyway, I'm ok with deprecation, it that looks the best option. > > However, the biggest problem of SEDF is its poor support for SMP, and > > lack of capability for setting scheduling parameters on a per-VCPU > > basis, which this series (rightfully) does not address. > > Imagine if, after proper review and cleanups, the set of changes from > > this series goes in, and no other follow up series makes it by feature > > freeze, 4.5 will have: > > - SCHED_SEDF deprecated, because it was lacking SMP support and suppor= t > > for per-VCPU scheduling parameters > > - SCHED_CBS, _lacking_ SMP support and support for per-VCPU scheduling= =20 > > parameters > > Not ideal. :-/ >=20 > If people aren't happy with that situation then I suppose we wouldn't > accept the series until CBS was more complete. >=20 Exactly my point. Thanks for summarizing. :-D > And this seems to me to be completely orthogonal to whether the approach > is to rename or rewrite. >=20 Indeed it is, and that's why I provided a full review to the core part of this patch series already. That being said, I felt the need of going a bit farther than that, and provide some more info on what a series like this should include, in order to make sense in a non RFC status, or at least my take at this. That is what this mail was all about. :-) Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-cnXiA3VY4h0B9WJgMZEh 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 iEYEABECAAYFAlO/6DUACgkQk4XaBE3IOsSfHgCdGI5hT0mZzRXVj6VgLs1i2CWL TuAAn1Vsl7B/vgrku9t/eTVIfL4lUXgb =m7aD -----END PGP SIGNATURE----- --=-cnXiA3VY4h0B9WJgMZEh-- --===============2972469066276573664== 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 --===============2972469066276573664==--