From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S933025Ab2JaAja (ORCPT ); Tue, 30 Oct 2012 20:39:30 -0400 Received: from mga02.intel.com ([134.134.136.20]:21748 "EHLO mga02.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1759123Ab2JaAef (ORCPT ); Tue, 30 Oct 2012 20:34:35 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.80,683,1344236400"; d="scan'208";a="213257358" From: Andi Kleen To: linux-kernel@vger.kernel.org Cc: acme@redhat.com, peterz@infradead.org, jolsa@redhat.com, eranian@google.com, mingo@kernel.org, namhyung@kernel.org, Andi Kleen Subject: [PATCH 18/32] perf, x86: Support for printing PMU state on spurious PMIs v3 Date: Tue, 30 Oct 2012 17:34:09 -0700 Message-Id: <1351643663-23828-19-git-send-email-andi@firstfloor.org> X-Mailer: git-send-email 1.7.7.6 In-Reply-To: <1351643663-23828-1-git-send-email-andi@firstfloor.org> References: <1351643663-23828-1-git-send-email-andi@firstfloor.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Andi Kleen I had some problems with spurious PMIs, so print the PMU state on a spurious one. This will not interact well with other NMI users. Disabled by default, has to be explicitely enabled through sysfs. Optional, but useful for debugging. v2: Move to /sys/devices/cpu v3: Print in more cases Signed-off-by: Andi Kleen --- arch/x86/kernel/cpu/perf_event.c | 3 +++ arch/x86/kernel/cpu/perf_event.h | 2 ++ arch/x86/kernel/cpu/perf_event_intel.c | 11 ++++++----- 3 files changed, 11 insertions(+), 5 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event.c b/arch/x86/kernel/cpu/perf_event.c index ec3c549..57bb4ce 100644 --- a/arch/x86/kernel/cpu/perf_event.c +++ b/arch/x86/kernel/cpu/perf_event.c @@ -38,6 +38,7 @@ #include "perf_event.h" struct x86_pmu x86_pmu __read_mostly; +int print_spurious_pmi __read_mostly; DEFINE_PER_CPU(struct cpu_hw_events, cpu_hw_events) = { .enabled = 1, @@ -1758,9 +1759,11 @@ static ssize_t set_attr_rdpmc(struct device *cdev, } static DEVICE_ATTR(rdpmc, S_IRUSR | S_IWUSR, get_attr_rdpmc, set_attr_rdpmc); +static DEVICE_INT_ATTR(print_spurious_pmi, 0644, print_spurious_pmi); static struct attribute *x86_pmu_attrs[] = { &dev_attr_rdpmc.attr, + &dev_attr_print_spurious_pmi.attr.attr, NULL, }; diff --git a/arch/x86/kernel/cpu/perf_event.h b/arch/x86/kernel/cpu/perf_event.h index d55e502..2ef5b20 100644 --- a/arch/x86/kernel/cpu/perf_event.h +++ b/arch/x86/kernel/cpu/perf_event.h @@ -664,3 +664,5 @@ static inline struct intel_shared_regs *allocate_shared_regs(int cpu) } #endif /* CONFIG_CPU_SUP_INTEL */ + +extern int print_spurious_pmi; diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 20caf0a..dc2f2a1 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -1146,11 +1146,8 @@ static int intel_pmu_handle_irq(struct pt_regs *regs) intel_pmu_disable_all(); handled = intel_pmu_drain_bts_buffer(); status = intel_pmu_get_status(); - if (!status) { - intel_pmu_enable_all(0); - return handled; - } - + if (!status) + goto done; loops = 0; again: intel_pmu_ack_status(status); @@ -1210,6 +1207,10 @@ again: goto again; done: + if (!handled && print_spurious_pmi) { + pr_debug("Spurious PMI\n"); + perf_event_print_debug(); + } intel_pmu_enable_all(0); return handled; } -- 1.7.7.6