From patchwork Thu Mar 19 19:21:15 2015 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Eduardo Habkost X-Patchwork-Id: 452184 Return-Path: X-Original-To: incoming@patchwork.ozlabs.org Delivered-To: patchwork-incoming@bilbo.ozlabs.org Received: from lists.gnu.org (lists.gnu.org [IPv6:2001:4830:134:3::11]) (using TLSv1 with cipher AES256-SHA (256/256 bits)) (No client certificate requested) by ozlabs.org (Postfix) with ESMTPS id 8A8151400EA for ; Fri, 20 Mar 2015 06:21:58 +1100 (AEDT) Received: from localhost ([::1]:40875 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYg0y-0003zY-52 for incoming@patchwork.ozlabs.org; Thu, 19 Mar 2015 15:21:56 -0400 Received: from eggs.gnu.org ([2001:4830:134:3::10]:51651) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYg0a-0003I6-19 for qemu-devel@nongnu.org; Thu, 19 Mar 2015 15:21:32 -0400 Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1YYg0T-0003tg-Oi for qemu-devel@nongnu.org; Thu, 19 Mar 2015 15:21:31 -0400 Received: from mx1.redhat.com ([209.132.183.28]:38120) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1YYg0T-0003tR-FL for qemu-devel@nongnu.org; Thu, 19 Mar 2015 15:21:25 -0400 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id t2JJLNW2002629 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Thu, 19 Mar 2015 15:21:23 -0400 Received: from localhost ([10.3.113.19]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t2JJLL4u026986; Thu, 19 Mar 2015 15:21:22 -0400 From: Eduardo Habkost To: qemu-devel@nongnu.org Date: Thu, 19 Mar 2015 16:21:15 -0300 Message-Id: <1426792875-11598-2-git-send-email-ehabkost@redhat.com> In-Reply-To: <1426792875-11598-1-git-send-email-ehabkost@redhat.com> References: <1426792875-11598-1-git-send-email-ehabkost@redhat.com> X-Scanned-By: MIMEDefang 2.68 on 10.5.11.24 X-detected-operating-system: by eggs.gnu.org: GNU/Linux 3.x X-Received-From: 209.132.183.28 Cc: Paolo Bonzini , Igor Mammedov , Hu Tao , "Michael S. Tsirkin" Subject: [Qemu-devel] [PATCH v5 1/1] numa: Print warning if no node is assigned to a CPU X-BeenThere: qemu-devel@nongnu.org X-Mailman-Version: 2.1.14 Precedence: list List-Id: List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org Sender: qemu-devel-bounces+incoming=patchwork.ozlabs.org@nongnu.org We need all possible CPUs (including hotplug ones) to be present in the SRAT when QEMU starts. QEMU already does that correctly today, the only problem is that when a CPU is omitted from the NUMA configuration, it is silently assigned to node 0. Check if all CPUs up to max_cpus are present in the NUMA configuration and warn about missing CPUs. Make it just a warning, to allow management software to be updated if necessary. In the future we may make it a fatal error instead. Command-line examples: * Correct, no warning: $ qemu-system-x86_64 -smp 2,maxcpus=4 $ qemu-system-x86_64 -smp 2,maxcpus=4 -numa node,cpus=0-3 * Incomplete, with warnings: $ qemu-system-x86_64 -smp 2,maxcpus=4 -numa node,cpus=0 qemu-system-x86_64: warning: CPU(s) not present in any NUMA nodes: 1 2 3 qemu-system-x86_64: warning: All CPU(s) up to maxcpus should be described in NUMA config $ qemu-system-x86_64 -smp 2,maxcpus=4 -numa node,cpus=0-2 qemu-system-x86_64: warning: CPU(s) not present in any NUMA nodes: 3 qemu-system-x86_64: warning: All CPU(s) up to maxcpus should be described in NUMA config Signed-off-by: Eduardo Habkost --- v1 -> v2: (no changes) v2 -> v3: * Use enumerate_cpus() and error_report() for error message * Simplify logic using bitmap_full() v3 -> v4: * Clarify error message, mention that all CPUs up to maxcpus need to be described in NUMA config v4 -> v5: * Commit log update, to make problem description clearer --- numa.c | 10 ++++++++++ 1 file changed, 10 insertions(+) diff --git a/numa.c b/numa.c index fe74e1e..c975fb2 100644 --- a/numa.c +++ b/numa.c @@ -200,6 +200,16 @@ static void validate_numa_cpus(void) bitmap_or(seen_cpus, seen_cpus, numa_info[i].node_cpu, MAX_CPUMASK_BITS); } + + if (!bitmap_full(seen_cpus, max_cpus)) { + char *msg; + bitmap_complement(seen_cpus, seen_cpus, max_cpus); + msg = enumerate_cpus(seen_cpus, max_cpus); + error_report("warning: CPU(s) not present in any NUMA nodes: %s", msg); + error_report("warning: All CPU(s) up to maxcpus should be described " + "in NUMA config"); + g_free(msg); + } } void parse_numa_opts(MachineClass *mc)