From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:34574) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1c3z4U-0000Gn-Rb for qemu-devel@nongnu.org; Tue, 08 Nov 2016 00:35:48 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1c3z4T-0002Eh-Pe for qemu-devel@nongnu.org; Tue, 08 Nov 2016 00:35:46 -0500 Date: Tue, 8 Nov 2016 14:44:41 +1100 From: David Gibson Message-ID: <20161108034441.GN28688@umbus.fritz.box> References: <1477825928-10803-1-git-send-email-david@gibson.dropbear.id.au> <1477825928-10803-5-git-send-email-david@gibson.dropbear.id.au> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="o+ZCuNqY+dEAKBWl" Content-Disposition: inline In-Reply-To: Subject: Re: [Qemu-devel] [RFC 04/17] pseries: Make cpu_update during CAS unconditional List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth Cc: nikunj@linux.vnet.ibm.com, aik@ozlabs.ru, mdroth@linux.vnet.ibm.com, lvivier@redhat.com, qemu-ppc@nongnu.org, qemu-devel@nongnu.org --o+ZCuNqY+dEAKBWl Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Nov 04, 2016 at 11:45:43AM +0100, Thomas Huth wrote: > On 30.10.2016 12:11, David Gibson wrote: > > spapr_h_cas_compose_response() includes a cpu_update parameter which > > controls whether it includes updated information on the CPUs in the dev= ice > > tree fragment returned from the ibm,client-architecture-support (CAS) c= all. > >=20 > > Providing the updated information is essential when CAS has negotiated > > compatibility options which require different cpu information to be > > presented to the guest. However, it should be safe to provide in other > > cases (it will just override the existing data in the device tree with > > identical data). This simplifies the code by removing the parameter and > > always providing the cpu update information. >=20 > But updating the CPU device tree again and again will also increase the > QEMU start-up time... Considering that guest start up time is sometimes > also an issue, do you think that this code simplification really worth > the effort here? Given how much it made my brain hurt to try to work the subsequent changes around that parameter; yes. If we really have problems with startup time we can revisit this - and we can probably do better in the context of cleaned up dt building. --=20 David Gibson | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you. NOT _the_ _other_ | _way_ _around_! http://www.ozlabs.org/~dgibson --o+ZCuNqY+dEAKBWl Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJYIUopAAoJEGw4ysog2bOSzGYQAL1jySMmImFqnCGBtnc3kSiW AbbW/nzdh7dHH7r+3aEOTAUtsbE6zsOQzBojaOURo2HhlfQkevhztJz7lK8BUZjJ 5MB4fykKbUDkRGwu1AjOCS5AkP5reho1dwaZhspks7FvD5ig3QRqMe1T5TNMW6nF 5VfqgfmKkOKe+ZsP18cFlWHmloHMRcWGxML8L45eqWHW4ACoGCJgqSXMIKlLgVJX B33LfUpeBUw2VsWEcjZe9znopAhCwMdDw1iPlcuTGu/2EumimMBvFmtJP9tcsbkL E7mfoqAvZGBa/x86mbAEvbkxYO5NG5ZowQSyUmj/TNyOClocSdGl+lItUriXW2jI JZhuu+uFOrXgKWAMvzGOCAYXZlJ9gGBWBHP9SQqfz7+zMaKEe8HEwUIzlmOgN2Bu F9phDqE2+iAp03WvWaJJ1llVXF4j09Tnz3A6Fwl3Vrf/KzAErAW8NB/2vaB3xOds FkvZqVqeTr/VUu5EwBL2O37T9mgNrk93ICK5uEHEOTA7n39Do24juYlanp0NUbFq Cmpc8FQBk0FedeIBtxwyPpC6w+Ay1ILwWxZc66EvIff5ZCK6zwEC25e1Y/sI7FFu qMs2HGxo6osEBuvavjzYs0R4zOsfWuSgZpNqt9RoQJp+Y/XQtnuGawL7Qehyqbym I2YXjX2G2eetaYO9l1Yh =+KV/ -----END PGP SIGNATURE----- --o+ZCuNqY+dEAKBWl--