From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753284AbaBOAoP (ORCPT ); Fri, 14 Feb 2014 19:44:15 -0500 Received: from mga01.intel.com ([192.55.52.88]:12299 "EHLO mga01.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753212AbaBOAoO (ORCPT ); Fri, 14 Feb 2014 19:44:14 -0500 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.95,848,1384329600"; d="scan'208";a="475564174" From: Andi Kleen To: peterz@infradead.org Cc: mingo@kernel.org, eranian@google.com, linux-kernel@vger.kernel.org, Markus Metzger , Andi Kleen Subject: [PATCH] perf, nmi: fix unknown NMI warning Date: Fri, 14 Feb 2014 16:44:08 -0800 Message-Id: <1392425048-5309-1-git-send-email-andi@firstfloor.org> X-Mailer: git-send-email 1.8.5.3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Markus Metzger [From Markus, just sending for him because he had problems with his mail] When using BTS on Core i7-4*, I get the below kernel warning. $ perf record -c 1 -e branches:u ls Message from syslogd@labpc1501 at Nov 11 15:49:25 ... kernel:[ 438.317893] Uhhuh. NMI received for unknown reason 31 on CPU 2. Message from syslogd@labpc1501 at Nov 11 15:49:25 ... kernel:[ 438.317920] Do you have a strange power saving mode enabled? Message from syslogd@labpc1501 at Nov 11 15:49:25 ... kernel:[ 438.317945] Dazed and confused, but trying to continue Make intel_pmu_handle_irq() take the full exit path when returning early. Signed-off-by: Markus Metzger Signed-off-by: Andi Kleen --- arch/x86/kernel/cpu/perf_event_intel.c | 6 ++---- 1 file changed, 2 insertions(+), 4 deletions(-) diff --git a/arch/x86/kernel/cpu/perf_event_intel.c b/arch/x86/kernel/cpu/perf_event_intel.c index 0fa4f24..698ae77 100644 --- a/arch/x86/kernel/cpu/perf_event_intel.c +++ b/arch/x86/kernel/cpu/perf_event_intel.c @@ -1361,10 +1361,8 @@ 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: -- 1.8.5.3