From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753610AbaJCF3l (ORCPT ); Fri, 3 Oct 2014 01:29:41 -0400 Received: from terminus.zytor.com ([198.137.202.10]:60911 "EHLO terminus.zytor.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752404AbaJCF3j (ORCPT ); Fri, 3 Oct 2014 01:29:39 -0400 Date: Thu, 2 Oct 2014 22:28:49 -0700 From: tip-bot for Wei Huang Message-ID: Cc: linux-kernel@vger.kernel.org, hpa@zytor.com, mingo@kernel.org, peterz@infradead.org, acme@kernel.org, wei@redhat.com, tglx@linutronix.de Reply-To: mingo@kernel.org, hpa@zytor.com, linux-kernel@vger.kernel.org, peterz@infradead.org, tglx@linutronix.de, wei@redhat.com, acme@kernel.org In-Reply-To: <1411617314-24659-1-git-send-email-wei@redhat.com> References: <1411617314-24659-1-git-send-email-wei@redhat.com> To: linux-tip-commits@vger.kernel.org Subject: [tip:perf/core] perf/x86: Tone down kernel messages when the PMU check fails in a virtual environment Git-Commit-ID: cc6cd47e7395bc05c5077009808b820633eb3f18 X-Mailer: tip-git-log-daemon Robot-ID: Robot-Unsubscribe: Contact to get blacklisted from these emails MIME-Version: 1.0 Content-Transfer-Encoding: 8bit Content-Type: text/plain; charset=UTF-8 Content-Disposition: inline Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Commit-ID: cc6cd47e7395bc05c5077009808b820633eb3f18 Gitweb: http://git.kernel.org/tip/cc6cd47e7395bc05c5077009808b820633eb3f18 Author: Wei Huang AuthorDate: Wed, 24 Sep 2014 22:55:14 -0500 Committer: Ingo Molnar CommitDate: Fri, 3 Oct 2014 06:04:41 +0200 perf/x86: Tone down kernel messages when the PMU check fails in a virtual environment PMU checking can fail due to various reasons. On native machine, this is mostly caused by faulty hardware and it is reasonable to use KERN_ERR in reporting. However, when kernel is running on virtualized environment, this checking can fail if virtual PMU is not supported (e.g. KVM on AMD host). It is annoying to see an error message on splash screen, even though we know such failure is benign on virtualized environment. This patch checks if the kernel is running in a virtualized environment. If so, it will use KERN_INFO in reporting, which reduces the syslog priority of them. This patch was tested successfully on KVM. Signed-off-by: Wei Huang Signed-off-by: Peter Zijlstra (Intel) Cc: Arnaldo Carvalho de Melo Link: http://lkml.kernel.org/r/1411617314-24659-1-git-send-email-wei@redhat.com Signed-off-by: Ingo Molnar --- arch/x86/kernel/cpu/perf_event.c | 3 ++- 1 file changed, 2 insertions(+), 1 deletion(-) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index 918d75f..16c7302 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -243,7 +243,8 @@ static bool check_hw_exists(void) msr_fail: printk(KERN_CONT "Broken PMU hardware detected, using software events only.\n"); - printk(KERN_ERR "Failed to access perfctr msr (MSR %x is %Lx)\n", reg, val_new); + printk(boot_cpu_has(X86_FEATURE_HYPERVISOR) ? KERN_INFO : KERN_ERR + "Failed to access perfctr msr (MSR %x is %Lx)\n", reg, val_new); return false; }