From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from eggs.gnu.org ([2001:4830:134:3::10]:40134) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1chBHw-0000ov-8V for qemu-devel@nongnu.org; Fri, 24 Feb 2017 03:31:41 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1chBHt-0000PQ-4s for qemu-devel@nongnu.org; Fri, 24 Feb 2017 03:31:40 -0500 Date: Fri, 24 Feb 2017 17:16:12 +1100 From: David Gibson Message-ID: <20170224061612.GE17615@umbus.fritz.box> References: <20170224045531.7026-1-aik@ozlabs.ru> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="UOi+gfmBpEZPw9cU" Content-Disposition: inline In-Reply-To: <20170224045531.7026-1-aik@ozlabs.ru> Subject: Re: [Qemu-devel] [PATCH qemu] sysemu: support up to 1024 vCPUs List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , To: Alexey Kardashevskiy Cc: qemu-devel@nongnu.org, qemu-ppc@nongnu.org, Greg Kurz , Greg Kurz --UOi+gfmBpEZPw9cU Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Fri, Feb 24, 2017 at 03:55:31PM +1100, Alexey Kardashevskiy wrote: > From: Greg Kurz >=20 > Some systems can already provide more than 255 hardware threads. >=20 > Bumping the QEMU limit to 1024 seems reasonable: > - it has no visible overhead in top; > - the limit itself has no effect on hot paths. >=20 > Cc: Greg Kurz > Signed-off-by: Alexey Kardashevskiy > --- >=20 > With ulimit -u/-n bumped (nproc and nofile), I was able to boot a guest > with 1024 CPUs, both with threads=3D1 and threads=3D8. >=20 > It takes time though - 3:15 to get to the guest shell but it is probably > expected on 160-threads machine. Applied, thanks. >=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 e465d7ac98..46b81a625d 100644 > --- a/hw/ppc/spapr.c > +++ b/hw/ppc/spapr.c > @@ -2712,7 +2712,7 @@ static void spapr_machine_class_init(ObjectClass *o= c, void *data) > mc->init =3D ppc_spapr_init; > mc->reset =3D ppc_spapr_reset; > mc->block_default_type =3D IF_SCSI; > - mc->max_cpus =3D 255; > + mc->max_cpus =3D 1024; > mc->no_parallel =3D 1; > mc->default_boot_order =3D ""; > mc->default_ram_size =3D 512 * M_BYTE; --=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 --UOi+gfmBpEZPw9cU Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- Version: GnuPG v2 iQIcBAEBCAAGBQJYr8+qAAoJEGw4ysog2bOSQEYQAK0FaCVzIFrpL/YGL/EgvN3p uN2/RKu+8rele52LZoJj34JtdZRifKWz6qYA9HeX0QWYEgr79q5hNojWNByxZtNr ZhOR+yrpjs11cRbl3AgQXDmDY9sbTUjWMzZ4LFhXRXVTtRe8iJdO5CEZXLjS0zxF 0STB4A5EMWa5s4qZ19y8axoJHnZ0lYBI5TsyrvL1jn1uNMUN7bYACaqxNnMIbTMA QERlnQkSQzNa/5qP/Nu4vD33CP1rFk+KOI5t53QkU8Aeh8HQMhOKV6TuACmSKKZ9 IgWGEAmaqFqJPSJuilprWimUYJg3AeBS+X4Lato4wMpzkOHqU79er4LF4hfyC1s3 VrFqLsNXBuPYD9X1QlTFajje/kdyKgX4OBmMrJXWzcYo0uZW4O1qKtBGTK2r8wb+ ks3jv2zb66csqyADHXt4Ymj4Df4iw6Mj/XR8/+2ROGMrcCZ7tbP/RFtBZJQDlDLs J0skKRnrnSTWCtqD6qDWVC0dm68CyvFpJhfFGCI0sCpaLR3UbYGY2Ud93Q1OPAxV YcSmkHRRGTNlIgKRprARdpJd1tdsojLHa+kS9CMp1TtArwtalMzyitBbf6+lXRiN NddO7UKgX5M4X5NE8p1OUl0+dweHAfKxEHdtrfc6bo5bwZO95o7+az1g6EwF93mz Z0qZ6HlRcDirRXmyG0P7 =hbwY -----END PGP SIGNATURE----- --UOi+gfmBpEZPw9cU--