Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1754150Ab2B0SAL (ORCPT ); Mon, 27 Feb 2012 13:00:11 -0500 Received: from mail-pw0-f46.google.com ([209.85.160.46]:54542 "EHLO mail-pw0-f46.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1753354Ab2B0SAJ (ORCPT ); Mon, 27 Feb 2012 13:00:09 -0500 Authentication-Results: mr.google.com; spf=pass (google.com: domain of dsahern@gmail.com designates 10.68.73.225 as permitted sender) smtp.mail=dsahern@gmail.com; dkim=pass header.i=dsahern@gmail.com Message-ID: <4F4BC4A4.10006@gmail.com> Date: Mon, 27 Feb 2012 11:00:04 -0700 From: David Ahern User-Agent: Mozilla/5.0 (Macintosh; Intel Mac OS X 10.7; rv:10.0.2) Gecko/20120216 Thunderbird/10.0.2 MIME-Version: 1.0 To: Stephane Eranian 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 Subject: Re: [PATCH] perf tools: fix guest mode monitoring on AMD References: <20120227173351.GA6945@quad> <4F4BC1AD.9030600@gmail.com> In-Reply-To: Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1882 Lines: 57 On 2/27/12 10:52 AM, Stephane Eranian wrote: > 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... agreed. Did you try reverting exclude_guest by default? -- 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/