From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: Fwd: [v3 14/15] Update Posted-Interrupts Descriptor during vCPU scheduling Date: Fri, 10 Jul 2015 15:59:47 +0200 Message-ID: <1436536787.22672.418.camel@citrix.com> References: <55918214.4030102@citrix.com> <1435633087.25170.274.camel@citrix.com> <1435825253.25170.406.camel@citrix.com> <1436445732.22672.321.camel@citrix.com> <1436532017.22672.411.camel@citrix.com> <20150710134713.GJ23038@l.oracle.com> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============8912599663502389804==" Return-path: In-Reply-To: <20150710134713.GJ23038@l.oracle.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: "Tian, Kevin" , "keir@xen.org" , George Dunlap , "andrew.cooper3@citrix.com" , xen-devel , "jbeulich@suse.com" , "Zhang, Yang Z" , "Wu, Feng" List-Id: xen-devel@lists.xenproject.org --===============8912599663502389804== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-03an/pUfbogSmeKxQR0x" --=-03an/pUfbogSmeKxQR0x Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Fri, 2015-07-10 at 09:47 -0400, Konrad Rzeszutek Wilk wrote: > On Fri, Jul 10, 2015 at 02:40:17PM +0200, Dario Faggioli wrote: > > However, there is no one single feature (e.g., for hardware enablement, > > like yours) that I can find, within Xen, that builds on top of runstate= s > > (the only exception is credit1 scheduler, and only it, using > > runstate.state_entry_time once... and I think that's quite bad of it, > > FWIW). >=20 > Linux kernel uses them. It ends up reporting the values for 'steal time' > as the RUNSTATE_runnable. Aka if you run 'top' and see 'st' - that is it. > It sure does, and it is in its own full right of doing it! I think I said that they're there for accounting and information reporting to upper layer, and Linux is what populates one of the (various) upper layers, as far as Xen is concerned, isn't it? What I'm arguing about is not them being there at all, nor about them being used for their own purpose, it's much rather about them being (ab)used for hardware enablement _in_Xen_ itself. :-) > > Theoretically speaking, runstates could well disappear, or change > > meaning, or be replaced by something else, and only the accounting and > > reporting code (as far as the hypervisor is concerned, of course) would > > suffer/need changing. >=20 > Please don't remove them! They helped me in tracking down a situation > where guests had 20% of them time-slice taken out by a global spinlock! > Hey, I said 'theoretically speaking'! :-) I don't have, and am not aware of any other plan to get rid of them.. So, fear nothing, they're not going anywhere... are are they? Mhwuawhuahwua :-D :-D Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-03an/pUfbogSmeKxQR0x 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 iEYEABECAAYFAlWfz90ACgkQk4XaBE3IOsRN8ACfU8HAPU433eHrxfOLYz10Odr7 GEQAoIZ0myPcpQBl4rnfUcewNXnrxtsx =ZGWC -----END PGP SIGNATURE----- --=-03an/pUfbogSmeKxQR0x-- --===============8912599663502389804== 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 --===============8912599663502389804==--