From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dario Faggioli Subject: Re: [PATCH] xen: postpone updating domains' node affinity when removing a CPU from a cpupool Date: Wed, 11 Mar 2015 10:32:46 +0000 Message-ID: <1426069963.21405.2.camel@citrix.com> References: <20150309164901.11859.95044.stgit@Solace.station> Mime-Version: 1.0 Content-Type: multipart/mixed; boundary="===============7887340620119958693==" Return-path: In-Reply-To: <20150309164901.11859.95044.stgit@Solace.station> Content-Language: en-US List-Unsubscribe: , List-Post: List-Help: List-Subscribe: , Sender: xen-devel-bounces@lists.xen.org Errors-To: xen-devel-bounces@lists.xen.org To: "xen-devel@lists.xen.org" Cc: Ian Jackson , "JBeulich@suse.com" List-Id: xen-devel@lists.xenproject.org --===============7887340620119958693== Content-Language: en-US Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="=-NUpUk4ksIO4XEJpzSR0Y" --=-NUpUk4ksIO4XEJpzSR0Y Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2015-03-09 at 17:49 +0100, Dario Faggioli wrote: > 93be8285 ("update domU's node-affinity on the cpupool_unassign_cpu() > path") does the right thing, but does it too early. In fact, it > is necessary to call domain_update_node_affinity() when a pCPU is > removed from a cpupool, but that must happen after the pCPU is > really gone from there. >=20 > More specifically, it is important that the update happens not > before cpu_disable_scheduler() is called on that pCPU, to give > that function the chance to fixup the vCPU affinity of the > domains residing in the cpupool, if that is necessary. >=20 > Calling it earlier, as it happens before this change, causes > (although only in rather awkward circumstances), the following: >=20 > (XEN) **************************************** > (XEN) Panic on CPU 0: > (XEN) Assertion '!cpumask_empty(dom_cpumask)' failed at domain.c:460 > (XEN) **************************************** >=20 Oh, and this affects 4.5, so, when we'll get there, a backport is in order, IMO (and I'll file the request as appropriate as soon as this will be in). Regards, Dario --=-NUpUk4ksIO4XEJpzSR0Y 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 iEYEABECAAYFAlUAGcsACgkQk4XaBE3IOsTx7gCgpG1J3UEpNYqaONtGzbDfn4p6 GiEAoI0ZwtPnSAGr7jd3DFYZT/qkjF0P =iIxj -----END PGP SIGNATURE----- --=-NUpUk4ksIO4XEJpzSR0Y-- --===============7887340620119958693== 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 --===============7887340620119958693==--