From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1757170Ab2BCRBh (ORCPT ); Fri, 3 Feb 2012 12:01:37 -0500 Received: from e28smtp06.in.ibm.com ([122.248.162.6]:37119 "EHLO e28smtp06.in.ibm.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1757114Ab2BCRBg (ORCPT ); Fri, 3 Feb 2012 12:01:36 -0500 Subject: [RFC PATCH] Perf: Fix an issue where perf report fails to show the proper percentage To: acme@redhat.com, mingo@elte.hu, linux-kernel@vger.kernel.org From: "Naveen N. Rao" Cc: robert.richter@amd.com, ananth@in.ibm.com, srikar@linux.vnet.ibm.com Date: Fri, 03 Feb 2012 22:31:13 +0530 Message-ID: <20120203170113.5190.25558.stgit@localhost6.localdomain6> User-Agent: StGit/0.15 MIME-Version: 1.0 Content-Type: text/plain; charset="utf-8" Content-Transfer-Encoding: 7bit x-cbid: 12020317-9574-0000-0000-0000013A79F3 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org This patch fixes an issue where perf report shows nan% for certain perf.data files. The below is from a report for a do_fork probe: -nan% sshd [kernel.kallsyms] [k] do_fork -nan% packagekitd [kernel.kallsyms] [k] do_fork -nan% dbus-daemon [kernel.kallsyms] [k] do_fork -nan% bash [kernel.kallsyms] [k] do_fork A git bisect shows commit f3bda2c as the cause. However, looking back through the git history, I saw commit 640c03c which seems to have removed the required initialization for perf_sample->period. The problem only started showing after commit f3bda2c. The below patch re-introduces the initialization and it fixes the problem for me. With the below patch, for the same perf.data: 73.08% bash [kernel.kallsyms] [k] do_fork 8.97% 11-dhclient [kernel.kallsyms] [k] do_fork 6.41% sshd [kernel.kallsyms] [k] do_fork 3.85% 20-chrony [kernel.kallsyms] [k] do_fork 2.56% sendmail [kernel.kallsyms] [k] do_fork This patch applies over current linux-tip commit 9949284. Signed-off-by: Naveen N. Rao --- tools/perf/util/evsel.c | 1 + 1 files changed, 1 insertions(+), 0 deletions(-) diff --git a/tools/perf/util/evsel.c b/tools/perf/util/evsel.c index dcfefab..9a11f9e 100644 --- a/tools/perf/util/evsel.c +++ b/tools/perf/util/evsel.c @@ -463,6 +463,7 @@ int perf_event__parse_sample(const union perf_event *event, u64 type, memset(data, 0, sizeof(*data)); data->cpu = data->pid = data->tid = -1; data->stream_id = data->id = data->time = -1ULL; + data->period = 1; if (event->header.type != PERF_RECORD_SAMPLE) { if (!sample_id_all)