From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [BUG] mistakenly wake in Xen's credit scheduler Date: Tue, 27 Oct 2015 10:53:39 +0100 Message-ID: <1445939619.2937.55.camel@citrix.com> References: Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============3401619821637218451==" 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 , suokun Cc: "xen-devel@lists.xen.org" List-Id: xen-devel@lists.xenproject.org --===============3401619821637218451== Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-bZBPYx1ulrUD9QnD/Jo7" --=-bZBPYx1ulrUD9QnD/Jo7 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Tue, 2015-10-27 at 09:44 +0000, George Dunlap wrote: > On Tue, Oct 27, 2015 at 5:59 AM, suokun wrote: > > Hi all, > >=20 > > The BOOST mechanism in Xen credit scheduler is designed to > > prioritize > > VM which has I/O-intensive application to handle the I/O request in > > time. However, this does not always work as expected. >=20 > Thanks for the exploration, and the analysis. >=20 Yep, indeed. :-) > The BOOST mechanism is part of the reason I began to write the > credit2 > scheduler, which we are hoping (any day now) to make the default > scheduler. It was designed specifically with the workload you > mention > in mind. =20 > The whole BOOST thing is an hack, and I don't have much problems believing it interacts poorly with the tickling mechanism, which, in Credit1, is not very precise and reliable (e.g., in Credit2, there is a 'tickled' mask). That being said, I'm looking at the analysis itself, and I'm not sure I understand what exactly you are suggesting it's going on... I will reply shortly with a few questions. > Would you care to try your test again and see how it fares? >=20 Well, that would be a lot useful, for sure! :-D Regards, Dario --=20 <> (Raistlin Majere) ----------------------------------------------------------------- Dario Faggioli, Ph.D, http://about.me/dario.faggioli Senior Software Engineer, Citrix Systems R&D Ltd., Cambridge (UK) --=-bZBPYx1ulrUD9QnD/Jo7 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 v1 iEYEABECAAYFAlYvSaMACgkQk4XaBE3IOsSgnwCfffMit6O9lD+Ogs/BRuD0XAJc BxsAoKXOPmo5DkUZBWZYP8FqFB/8dvE2 =fft3 -----END PGP SIGNATURE----- --=-bZBPYx1ulrUD9QnD/Jo7-- --===============3401619821637218451== 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 --===============3401619821637218451==--