From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:43718) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1b8GmO-0003Gt-VC for qemu-devel@nongnu.org; Wed, 01 Jun 2016 20:46:33 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1b8GmK-0002NT-Oe for qemu-devel@nongnu.org; Wed, 01 Jun 2016 20:46:31 -0400 Date: Thu, 2 Jun 2016 10:42:23 +1000 From: David Gibson Message-ID: <20160602004222.GE15455@voom.fritz.box> References: <201606010952.u519n6ri025307@mx0a-001b2d01.pphosted.com> <574EB66E.1040805@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha1; protocol="application/pgp-signature"; boundary="vv4Sf/kQfcwinyKX" Content-Disposition: inline In-Reply-To: <574EB66E.1040805@redhat.com> Subject: Re: [Qemu-devel] [RFC PATCH v0 0/2] Increase max memslots to 512 for PowerPC List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Thomas Huth Cc: Bharata B Rao , qemu-devel@nongnu.org, qemu-ppc@nongnu.org, imammedo@redhat.com, pbonzini@redhat.com --vv4Sf/kQfcwinyKX Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Wed, Jun 01, 2016 at 12:18:22PM +0200, Thomas Huth wrote: > On 01.06.2016 11:51, Bharata B Rao wrote: > > Recently the number of memory slots supported by KVM for PowerPC was ch= anged > > from 32 to 512. QEMU was restricting the user specifiable hot-pluggable= memory > > slots to 32. This patchset changes that to 512. > >=20 > > This allows more number of slots to be available for memory hotplugging. >=20 > It's certainly a good idea to increase the number of slots for > hot-pluggable memory. But should we really increase it to the full > maximum of 512 slots? The in-kernel slots are shared with other memory > regions, too, e.g. the memory slots for PCI cards. So if you allow the > users to plug all slots with DIMMs, they certainly will run into > problems there again later. >=20 > I think x86 is also using 256 DIMM slots only on purpose (see > https://lkml.org/lkml/2014/11/14/328 for example), so we should maybe > also limit the max. number of DIMM slots on spapr to > kvm_get_max_memslots() divided by two ? I tend to agree. I've held off on merging 2/2 pending outcome of this discussion. --=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 --vv4Sf/kQfcwinyKX Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v1 iQIcBAEBAgAGBQJXT4DuAAoJEGw4ysog2bOSRqEP/iZItPKneQuDBi+Y0PwFHy0k fL2uZZ2oZUDwYIsYO0kKS5trcc+jGQVtgYSbAj5Bg/KvXKulwjml5tZDWBTX7895 HyoglH11sEo0e6yJmUjvu3Tr89MWEqK3QSVGD9/P6Ix6w8Kett/Pwiz8DUIUt3eU ZY98MO4beODcEdi877Q8hBdJEECIhnpowFGvG4MCX0+Krs8m+BOF7hZbwucFnViR 3OvtfI3JrkhoJme86ygtrF76PJyqf6LdaxY5neVPkQh/5qBXpTpmbIeHafc7WAGa lcYbrZ3/zt2/0Zu14YO9b7FjH10orB1v/tAAAHqbWd2TRvadD/TcPcLzXy4R3qC+ No18vPXsuju8QocZ0FMAs15qqXG7PQMBgDSUSD5fpC2WulO1SCGPpei7jDiC4xcI rmvhgSSjD+nlO1lOi5eQ+JI0YaLEvcImdPYRtrH+DCAs0Gz1TLlWXma4ZMloXBn8 L79bBbK0gVvEpveidl67IIkR8fE7yjGkrcBc3RFiL5ejvqKqjQjFJznIUT206bNh ZyI3b1qWE69M6Ec0XEGKwqAW2Olxv03JqMtr1DZ9JmZbyJTL2kiJ3Dmo7Sd54ZuY Ot29hQ570GfscyRsgf9UX0zuvPOv6LQFyhcGBNT8MV6d9vQEGKqLi94pG4zxkldX weQTNlWsY4xB8EpMkSro =VcLr -----END PGP SIGNATURE----- --vv4Sf/kQfcwinyKX--