From nobody Tue May 7 09:10:34 2024 Delivered-To: importer@patchew.org Received-SPF: pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) client-ip=208.118.235.17; envelope-from=qemu-devel-bounces+importer=patchew.org@nongnu.org; helo=lists.gnu.org; Authentication-Results: mx.zoho.com; spf=pass (zoho.com: domain of gnu.org designates 208.118.235.17 as permitted sender) smtp.mailfrom=qemu-devel-bounces+importer=patchew.org@nongnu.org; Return-Path: Received: from lists.gnu.org (lists.gnu.org [208.118.235.17]) by mx.zohomail.com with SMTPS id 1487912259358269.8398847996068; Thu, 23 Feb 2017 20:57:39 -0800 (PST) Received: from localhost ([::1]:34622 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ch7wm-0007Oi-3D for importer@patchew.org; Thu, 23 Feb 2017 23:57:36 -0500 Received: from eggs.gnu.org ([2001:4830:134:3::10]:54126) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ch7vP-0006aP-P6 for qemu-devel@nongnu.org; Thu, 23 Feb 2017 23:56:12 -0500 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ch7vM-0007wE-ON for qemu-devel@nongnu.org; Thu, 23 Feb 2017 23:56:11 -0500 Received: from ozlabs.ru ([107.173.13.209]:47872) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ch7vM-0007vQ-He; Thu, 23 Feb 2017 23:56:08 -0500 Received: from vpl2.ozlabs.ibm.com (localhost [IPv6:::1]) by ozlabs.ru (Postfix) with ESMTP id DF1D73A60395; Thu, 23 Feb 2017 23:55:24 -0500 (EST) From: Alexey Kardashevskiy To: qemu-devel@nongnu.org Date: Fri, 24 Feb 2017 15:55:31 +1100 Message-Id: <20170224045531.7026-1-aik@ozlabs.ru> X-Mailer: git-send-email 2.11.0 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x [fuzzy] X-Received-From: 107.173.13.209 Subject: [Qemu-devel] [PATCH qemu] sysemu: support up to 1024 vCPUs X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Cc: Alexey Kardashevskiy , Greg Kurz , qemu-ppc@nongnu.org, Greg Kurz , David Gibson Errors-To: qemu-devel-bounces+importer=patchew.org@nongnu.org Sender: "Qemu-devel" X-ZohoMail: RSF_0 Z_629925259 SPT_0 Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" From: Greg Kurz Some systems can already provide more than 255 hardware threads. Bumping the QEMU limit to 1024 seems reasonable: - it has no visible overhead in top; - the limit itself has no effect on hot paths. Cc: Greg Kurz Signed-off-by: Alexey Kardashevskiy --- 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. It takes time though - 3:15 to get to the guest shell but it is probably expected on 160-threads machine. --- hw/ppc/spapr.c | 2 +- 1 file changed, 1 insertion(+), 1 deletion(-) 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 *oc,= 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 2.11.0