Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753965Ab2B0Rw2 (ORCPT ); Mon, 27 Feb 2012 12:52:28 -0500 Received: from mail-lpp01m010-f46.google.com ([209.85.215.46]:39316 "EHLO mail-lpp01m010-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752615Ab2B0Rw1 convert rfc822-to-8bit (ORCPT ); Mon, 27 Feb 2012 12:52:27 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of eranian@google.com designates 10.152.145.135 as permitted sender) smtp.mail=eranian@google.com; dkim=pass header.i=eranian@google.com MIME-Version: 1.0 In-Reply-To: <4F4BC1AD.9030600@gmail.com> References: <20120227173351.GA6945@quad> <4F4BC1AD.9030600@gmail.com> Date: Mon, 27 Feb 2012 18:52:25 +0100 Message-ID: Subject: Re: [PATCH] perf tools: fix guest mode monitoring on AMD From: Stephane Eranian To: David Ahern Cc: linux-kernel@vger.kernel.org, acme@redhat.com, robert.richter@amd.com, peterz@infradead.org, mingo@elte.hu, joro@8bytes.org, gleb@redhat.com, joerg.roedel@amd.com Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8BIT X-System-Of-Record: true Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 2095 Lines: 68 On Mon, Feb 27, 2012 at 6:47 PM, David Ahern wrote: > On 2/27/12 10:33 AM, Stephane Eranian wrote: >> >> Commit: >> >> 1aed267 perf kvm: Do guest-only counting by default >> >> introduced a bug on AMD systems whereby simple commands: >> >> $ perf stat ls >> Performance counter stats for 'ls': >>                  0 cycles                    #    0.000 GHz >>        0.003704596 seconds time elapsed >> >> would not count anything anymore. Same results for perf record. >> >> I tracked it down to guest mode exclusion being enabled >> by default leading to attr->exclude_guest = 1. When >> not operating under any sort of virtualization, this >> causes the PMU not to count anything. >> >> The fix disables guest exclusion by default. >> >> Signed-off-by: Stephane Eranian >> --- >> >> diff --git a/tools/perf/util/util.c b/tools/perf/util/util.c >> index 8109a90..c1017b3 100644 >> --- a/tools/perf/util/util.c >> +++ b/tools/perf/util/util.c >> @@ -6,7 +6,7 @@ >>   * XXX We need to find a better place for these things... >>   */ >>  bool perf_host  = true; >> -bool perf_guest = false; >> +bool perf_guest = true; > > > This was recently reverted to false by > c4a7dca92bbb9881a5d678720f1d0c2153499749 > > See: https://lkml.org/lkml/2012/2/8/234 > Yeah, but that causes simple commands such as "perf stat -e cycles ls" to return 0 count. So either you get a segfault or you get zero count. There is something else going on here... > David > >> >>  void event_attr_init(struct perf_event_attr *attr) >>  { >> -- >> 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/ > > -- 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/