Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1758177AbaJCWVV (ORCPT ); Fri, 3 Oct 2014 18:21:21 -0400 Received: from mail.linuxfoundation.org ([140.211.169.12]:47126 "EHLO mail.linuxfoundation.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1758056AbaJCWQU (ORCPT ); Fri, 3 Oct 2014 18:16:20 -0400 From: Greg Kroah-Hartman To: linux-kernel@vger.kernel.org Cc: Greg Kroah-Hartman , stable@vger.kernel.org, Venkatesh Srinivas , Peter Zijlstra , zheng.z.yan@intel.com, eranian@google.com, ak@linux.intel.com, Ingo Molnar , Thomas D Subject: [PATCH 3.14 233/238] perf/x86/intel: Use rdmsrl_safe() when initializing RAPL PMU Date: Fri, 3 Oct 2014 14:32:28 -0700 Message-Id: <20141003212921.121289341@linuxfoundation.org> X-Mailer: git-send-email 2.1.2 In-Reply-To: <20141003212913.680985295@linuxfoundation.org> References: <20141003212913.680985295@linuxfoundation.org> User-Agent: quilt/0.63-1 MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org 3.14-stable review patch. If anyone has any objections, please let me know. ------------------ From: Venkatesh Srinivas commit 24223657806a0ebd0ae5c9caaf7b021091889cf2 upstream. CPUs which should support the RAPL counters according to Family/Model/Stepping may still issue #GP when attempting to access the RAPL MSRs. This may happen when Linux is running under KVM and we are passing-through host F/M/S data, for example. Use rdmsrl_safe to first access the RAPL_POWER_UNIT MSR; if this fails, do not attempt to use this PMU. Signed-off-by: Venkatesh Srinivas Signed-off-by: Peter Zijlstra Link: http://lkml.kernel.org/r/1394739386-22260-1-git-send-email-venkateshs@google.com Cc: zheng.z.yan@intel.com Cc: eranian@google.com Cc: ak@linux.intel.com Cc: linux-kernel@vger.kernel.org [ The patch also silently fixes another bug: rapl_pmu_init() didn't handle the memory alloc failure case previously. ] Signed-off-by: Ingo Molnar [backport by whissi] Cc: Thomas D Signed-off-by: Greg Kroah-Hartman --- arch/x86/kernel/cpu/perf_event_intel_rapl.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) --- a/arch/x86/kernel/cpu/perf_event_intel_rapl.c +++ b/arch/x86/kernel/cpu/perf_event_intel_rapl.c @@ -511,6 +511,7 @@ static int rapl_cpu_prepare(int cpu) struct rapl_pmu *pmu = per_cpu(rapl_pmu, cpu); int phys_id = topology_physical_package_id(cpu); u64 ms; + u64 msr_rapl_power_unit_bits; if (pmu) return 0; @@ -518,6 +519,9 @@ static int rapl_cpu_prepare(int cpu) if (phys_id < 0) return -1; + if (!rdmsrl_safe(MSR_RAPL_POWER_UNIT, &msr_rapl_power_unit_bits)) + return -1; + pmu = kzalloc_node(sizeof(*pmu), GFP_KERNEL, cpu_to_node(cpu)); if (!pmu) return -1; @@ -531,8 +535,7 @@ static int rapl_cpu_prepare(int cpu) * * we cache in local PMU instance */ - rdmsrl(MSR_RAPL_POWER_UNIT, pmu->hw_unit); - pmu->hw_unit = (pmu->hw_unit >> 8) & 0x1FULL; + pmu->hw_unit = (msr_rapl_power_unit_bits >> 8) & 0x1FULL; pmu->pmu = &rapl_pmu_class; /* @@ -649,7 +652,9 @@ static int __init rapl_pmu_init(void) get_online_cpus(); for_each_online_cpu(cpu) { - rapl_cpu_prepare(cpu); + ret = rapl_cpu_prepare(cpu); + if (ret) + goto out; rapl_cpu_init(cpu); } @@ -672,6 +677,7 @@ static int __init rapl_pmu_init(void) hweight32(rapl_cntr_mask), ktime_to_ms(pmu->timer_interval)); +out: put_online_cpus(); return 0; -- To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/