From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755030Ab3I3LUN (ORCPT ); Mon, 30 Sep 2013 07:20:13 -0400 Received: from mail-pb0-f51.google.com ([209.85.160.51]:42677 "EHLO mail-pb0-f51.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754555Ab3I3LT5 (ORCPT ); Mon, 30 Sep 2013 07:19:57 -0400 From: Ramkumar Ramachandra To: LKML Cc: Ingo Molnar , Arnaldo Carvalho de Melo , Peter Zijlstra , Paul Mackerras Subject: [PATCH 2/2] perf tool: don't print bogus data on -e cycles Date: Mon, 30 Sep 2013 16:43:05 +0530 Message-Id: <1380539585-23859-3-git-send-email-artagnon@gmail.com> X-Mailer: git-send-email 1.8.4.477.g5d89aa9 In-Reply-To: <1380539585-23859-1-git-send-email-artagnon@gmail.com> References: <1380539585-23859-1-git-send-email-artagnon@gmail.com> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org When only the cycles event is requested: $ perf stat -e cycles dd if=/dev/zero of=/dev/null count=1000000 1000000+0 records in 1000000+0 records out 512000000 bytes (512 MB) copied, 0.26123 s, 2.0 GB/s Performance counter stats for 'dd if=/dev/zero of=/dev/null count=1000000': 911,626,453 cycles # 0.000 GHz 0.262113350 seconds time elapsed The 0.000 GHz comment in the output is totally bogus and misleading. It happens because update_shadow_stats() doesn't touch runtime_nsecs_stats; it is only written when a requested counter matches a SW_TASK_CLOCK. In our case, since we have only requested HW_CPU_CYCLES, runtime_nsecs_stats is unavailable. So, omit printing the comment altogether. Cc: Ingo Molnar Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Arnaldo Carvalho de Melo Signed-off-by: Ramkumar Ramachandra --- tools/perf/builtin-stat.c | 9 ++++----- 1 file changed, 4 insertions(+), 5 deletions(-) diff --git a/tools/perf/builtin-stat.c b/tools/perf/builtin-stat.c index f686d5f..cc167ae 100644 --- a/tools/perf/builtin-stat.c +++ b/tools/perf/builtin-stat.c @@ -918,11 +918,10 @@ static void abs_printout(int cpu, int nr, struct perf_evsel *evsel, double avg) print_stalled_cycles_backend(cpu, evsel, avg); } else if (perf_evsel__match(evsel, HARDWARE, HW_CPU_CYCLES)) { total = avg_stats(&runtime_nsecs_stats[cpu]); - - if (total) - ratio = 1.0 * avg / total; - - fprintf(output, " # %8.3f GHz ", ratio); + if (total) { + ratio = avg / total; + fprintf(output, " # %8.3f GHz ", ratio); + } } else if (runtime_nsecs_stats[cpu].n != 0) { char unit = 'M'; -- 1.8.4.477.g5d89aa9