From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:33136) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gPIVS-0001Bj-NY for qemu-devel@nongnu.org; Tue, 20 Nov 2018 21:44:47 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1gPIVP-000285-JD for qemu-devel@nongnu.org; Tue, 20 Nov 2018 21:44:46 -0500 Date: Wed, 21 Nov 2018 13:44:22 +1100 From: David Gibson Message-ID: <20181121024422.GA21985@umbus> References: <1542644585-87579-1-git-send-email-spopovyc@redhat.com> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="wRRV7LY7NUeQGEoC" Content-Disposition: inline In-Reply-To: <1542644585-87579-1-git-send-email-spopovyc@redhat.com> Subject: Re: [Qemu-devel] [PATCH for 3.1 v2] spapr: Fix ibm, max-associativity-domains property number of nodes List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Serhii Popovych Cc: qemu-ppc@nongnu.org, lvivier@redhat.com, qemu-devel@nongnu.org --wRRV7LY7NUeQGEoC Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Mon, Nov 19, 2018 at 11:23:05AM -0500, Serhii Popovych wrote: > Laurent Vivier reported off by one with maximum number of NUMA nodes > provided by qemu-kvm being less by one than required according to > description of "ibm,max-associativity-domains" property in LoPAPR. >=20 > It appears that I incorrectly treated LoPAPR description of this > property assuming it provides last valid domain (NUMA node here) > instead of maximum number of domains. >=20 > ### Before hot-add >=20 > (qemu) info numa > 3 nodes > node 0 cpus: 0 > node 0 size: 0 MB > node 0 plugged: 0 MB > node 1 cpus: > node 1 size: 1024 MB > node 1 plugged: 0 MB > node 2 cpus: > node 2 size: 0 MB > node 2 plugged: 0 MB >=20 > $ numactl -H > available: 2 nodes (0-1) > node 0 cpus: 0 > node 0 size: 0 MB > node 0 free: 0 MB > node 1 cpus: > node 1 size: 999 MB > node 1 free: 658 MB > node distances: > node 0 1 > 0: 10 40 > 1: 40 10 >=20 > ### Hot-add >=20 > (qemu) object_add memory-backend-ram,id=3Dmem0,size=3D1G > (qemu) device_add pc-dimm,id=3Ddimm1,memdev=3Dmem0,node=3D2 > (qemu) [ 87.704898] pseries-hotplug-mem: Attempting to hot-add 4 ... > > [ 87.705128] lpar: Attempting to resize HPT to shift 21 > ... >=20 > ### After hot-add >=20 > (qemu) info numa > 3 nodes > node 0 cpus: 0 > node 0 size: 0 MB > node 0 plugged: 0 MB > node 1 cpus: > node 1 size: 1024 MB > node 1 plugged: 0 MB > node 2 cpus: > node 2 size: 1024 MB > node 2 plugged: 1024 MB >=20 > $ numactl -H > available: 2 nodes (0-1) > ^^^^^^^^^^^^^^^^^^^^^^^^ > Still only two nodes (and memory hot-added to node 0 below) > node 0 cpus: 0 > node 0 size: 1024 MB > node 0 free: 1021 MB > node 1 cpus: > node 1 size: 999 MB > node 1 free: 658 MB > node distances: > node 0 1 > 0: 10 40 > 1: 40 10 >=20 > After fix applied numactl(8) reports 3 nodes available and memory > plugged into node 2 as expected. >=20 > Fixes: da9f80fbad21 ("spapr: Add ibm,max-associativity-domains property") > Reported-by: Laurent Vivier > Signed-off-by: Serhii Popovych > --- > v2 > Remove now unneeded ?: statement previously used to catch -1 as numa no= de > causing Linux guests hanging on boot. >=20 > hw/ppc/spapr.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) >=20 > diff --git a/hw/ppc/spapr.c b/hw/ppc/spapr.c > index 7afd1a1..a7171fb 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -1033,7 +1033,7 @@ static void spapr_dt_rtas(sPAPRMachineState *spapr,= void *fdt) > cpu_to_be32(0), > cpu_to_be32(0), > cpu_to_be32(0), > - cpu_to_be32(nb_numa_nodes ? nb_numa_nodes - 1 : 0), > + cpu_to_be32(nb_numa_nodes), Sorry, I know this got discussed in the thread on the earlier version, but I'd prefer we leave the conditional expression in here. qemu makes a distinction between "non NUMA" (nb_numa_nodes =3D=3D 0) and "NUMA with one node" (nb_numa_nodes =3D=3D 1). But from a PAPR guests's point of view these are equivalent. I don't want to present two different cases to the guest when we don't need to, so even though the guest can handle it, I'd prefer we put a '1' here for both the nb_numa_nodes =3D=3D 0 and nb_numa_nodes =3D=3D 1 case. > }; > =20 > _FDT(rtas =3D fdt_add_subnode(fdt, 0, "rtas")); --=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 --wRRV7LY7NUeQGEoC Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEdfRlhq5hpmzETofcbDjKyiDZs5IFAlv0xoQACgkQbDjKyiDZ s5IutQ//QmSL1HhpGMDPPe1D7Cpm0tgamNA5SY/uDCSOmWaomEsQJupaxeYKK25q cyoIvD6+IYi2WULIx9cYlwzjpEmj5TlnYzXTjgLyuLH8bXdaZj95jKtll/SHvrNW aHyGTysI2da8e8GiJZCNpTQkJ55ELuozSYhMdoguyw2oz4W4APzgJOPCvzvDZQQS b8UgmX1KFhBGfShOcDzmrBUTy8ejJDpgCYWsEIEGaS7I0Nh+VKqD5QJhdI04lDPd W82iBPTourcgCA4+kifyqEUzvTdFXSsPwrT5gBRwoAkae1lHaZhJbgusxdCQ8WT6 Aj/v+xuJ0Tu3CHPt6TzJhFy/YtIPVjpKXu4Wg32+WBm7ruIwvcBEupCGoyZpc9Nj hQvnwK2oZlu6QD76hZhBz+0TFII41RI2Zjhs58B8+WeEtNPhOvF5UB3iWgOh366C jCeq5wfNd6k1tgH8Ecs8j7WH5LQfjuCbiBgFyVBIy//tz4odgTCQ4wsuDuAyMLQI 3Q7LR5wKI1kHcDVf/YQ43xbUuAY4977F10ko0LSnLia9j4rZJBgRkB9bUhetaXoJ 5Yx3sRkH5Rg5VwvV1WGw2LGh/Jzv1MHsociysbcM/0GdmO6PDfQvpQTlF44ld4Ux hEva6CvImPUnlZPPfq00ypnl6Y+xsN5mOHhrByDzO1pYIm6j1Jo= =HKWu -----END PGP SIGNATURE----- --wRRV7LY7NUeQGEoC--