From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH v3 1/4] xen: add real time scheduler rtds Date: Mon, 22 Sep 2014 19:26:28 +0200 Message-ID: <1411406788.4116.26.camel@Solace.lan> References: <1410730649-2417-1-git-send-email-mengxu@cis.upenn.edu> <1410730649-2417-2-git-send-email-mengxu@cis.upenn.edu> <541B038D.4030307@eu.citrix.com> <20140919164422.GA9619@laptop.dumpdata.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============0012353498532836517==" Return-path: In-Reply-To: <20140919164422.GA9619@laptop.dumpdata.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: Konrad Rzeszutek Wilk Cc: ian.campbell@citrix.com, xisisu@gmail.com, stefano.stabellini@eu.citrix.com, George Dunlap , lu@cse.wustl.edu, ian.jackson@eu.citrix.com, xen-devel@lists.xen.org, ptxlinh@gmail.com, xumengpanda@gmail.com, Meng Xu , JBeulich@suse.com, chaowang@wustl.edu, lichong659@gmail.com, dgolomb@seas.upenn.edu List-Id: xen-devel@lists.xenproject.org --===============0012353498532836517== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-ion67WEMu3G7AAiifatp" --=-ion67WEMu3G7AAiifatp Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On ven, 2014-09-19 at 12:44 -0400, Konrad Rzeszutek Wilk wrote: > On Thu, Sep 18, 2014 at 05:08:45PM +0100, George Dunlap wrote: > > deadline, and then address the things I'm bringing up here? Or would i= t be > > better to wait until all the issues are sorted and then check it in (ev= en if > > it's after the deadline)? >=20 > We can check it in after the deadline - and have those issues resolved. >=20 FWIW, I think the series looks good now, and in fact I sent in my Reviewed-by for all of it. > I am basing this on the assumption that: > - The risks of regressions to the rest of schedulers is nill (as this is= all > new codepaths (as this is all > - The risks of regressions to the rest of the code-base is nill (as this= is all > new). > - The resolution of the 'couple of things' are not going to lead to more > 'couple of things' and lead to re-design. > This is all true, IMO. > The common code that is touched does not look scary to me. And both of th= e > scheduler maintainers - you and Dariof are OK with the design and the pa= tchset > (minus the 'couple of things'). >=20 Exactly. > Are we aim to have this be experimental for Xen 4.5 or do we want this > to be on the 'stable' ? > Not sure. What I'm sure about is that 1) the interface needs to change a bit, to include support for the per-vcpu parameters setting (although, that can happen in a backward compatible way, i.e., not touching or altering neither the look nor the semantic or the interface we'll be checking in if we take v4) 2) there is _a_lot_ to gain, from a performance point of view, and Meng already agreed on continuing working toward that, after 4.5 Having it in is, IMO, important, especially for the new embedded/mobile/automotive uses of Xen we're seeing in these days (in fact, I think GlobalLogic is using RT-Xen already, so the upstreaming of this scheduler would be quite useful at least to them [correct me if I'm wrong]). However, given 2 above, if we mark it as stable, we risk that people (mostly people not yet involved into Xen development and not on this mailing list) would try it, run into non-optimal performance, and get upset/angry. For that reason, I think I'd go for 'experimental for 4.5'. Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-ion67WEMu3G7AAiifatp 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 iEYEABECAAYFAlQgW8QACgkQk4XaBE3IOsSPFACgqNDcwyEL45c9Cy4cBs91mUJQ 5EAAnjaqE/OiTvtnu2n+wqzkFk5F2xjq =NT1S -----END PGP SIGNATURE----- --=-ion67WEMu3G7AAiifatp-- --===============0012353498532836517== 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 --===============0012353498532836517==--