Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757333Ab0KSXb1 (ORCPT ); Fri, 19 Nov 2010 18:31:27 -0500 Received: from mail.windriver.com ([147.11.1.11]:53071 "EHLO mail.windriver.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1756989Ab0KSXb0 (ORCPT ); Fri, 19 Nov 2010 18:31:26 -0500 Message-ID: <4CE708AA.7030405@windriver.com> Date: Fri, 19 Nov 2010 17:30:50 -0600 From: Jason Wessel User-Agent: Thunderbird 2.0.0.24 (X11/20101027) MIME-Version: 1.0 To: Peter Zijlstra CC: Don Zickus , Ingo Molnar , Robert Richter , ying.huang@intel.com, Andi Kleen , LKML , Frederic Weisbecker Subject: Re: [V2 PATCH 0/6] x86, NMI: give NMI handler a face-lift References: <4CE2E3C3.6060800@windriver.com> <20101118080516.GJ32621@elte.hu> <4CE52048.5080802@windriver.com> <1290086232.2109.1507.camel@laptop> <20101118193247.GF18100@redhat.com> <4CE583D0.8050407@windriver.com> <20101118200807.GC8131@redhat.com> <1290112234.2109.1534.camel@laptop> <20101119165952.GJ18100@redhat.com> <1290191158.2109.1614.camel@laptop> <20101119225902.GQ18100@redhat.com> <1290208179.2114.13.camel@laptop> In-Reply-To: <1290208179.2114.13.camel@laptop> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-OriginalArrivalTime: 19 Nov 2010 23:30:53.0470 (UTC) FILETIME=[CED7EBE0:01CB8841] Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1315 Lines: 39 On 11/19/2010 05:09 PM, Peter Zijlstra wrote: > On Fri, 2010-11-19 at 17:59 -0500, Don Zickus wrote: >> >> @@ -1371,6 +1385,12 @@ void __init init_hw_perf_events(void) >> >> pmu_check_apic(); >> >> + /* sanity check that the hardware exists or is emulated */ >> + if (!check_hw_exists()) { >> + pr_cont("no PMU driver, software events only.\n"); >> + return; >> + } > > Maybe report something like this: > "Broken PMU hardware detected, software events only." > > Because this is really not something that's supposed to happen. The kgdb test suite is passing with Don's perf detect logic, so we are back to good. I am in agreement with Peter about the message indicating that it is broken hardware. We don't in any way shape or form want leave the illusion this works in the VM. # dmesg |grep Per <6>Performance Events: no PMU driver, software events only. Tested on qemu and kvm, several revisions worth, because it is all automated. Tested-by: Jason Wessel Thanks, Jason. -- 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/