From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1755113AbaHBSPv (ORCPT ); Sat, 2 Aug 2014 14:15:51 -0400 Received: from smtp2-g21.free.fr ([212.27.42.2]:52904 "EHLO smtp2-g21.free.fr" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1754723AbaHBSPu (ORCPT ); Sat, 2 Aug 2014 14:15:50 -0400 From: Yann Droneaud To: Jiri Olsa Cc: Yann Droneaud , linux-kernel@vger.kernel.org, Andi Kleen , Arnaldo Carvalho de Melo , Ingo Molnar , Peter Zijlstra , Paul Mackerras , Adrian Hunter , David Ahern , Frederic Weisbecker , Namhyung Kim , Stephane Eranian , William Cohen Subject: [PATCH] perf tools: report PERF_FLAG_FD_CLOEXEC probing error once Date: Sat, 2 Aug 2014 20:13:22 +0200 Message-Id: <1407003202-13672-1-git-send-email-ydroneaud@opteya.com> X-Mailer: git-send-email 1.9.3 In-Reply-To: <1406908014-8312-1-git-send-email-jolsa@kernel.org> References: <1406908014-8312-1-git-send-email-jolsa@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org In case of failure, unrelated to PERF_FLAG_FD_CLOEXEC, perf_flag_probe() reports the error twice. For example: $ perf record ls Error: perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error 16 (Device or resource busy) perf_event_open(..., 0) failed unexpectedly with error 16 (Device or resource busy) The PMU counters are busy/taken by another profiler. We found oprofile daemon running, please stop it and try again. This patch changes the function to only report a second error message when the two calls to perf_even_open(2) fail with different error codes. Cc: Andi Kleen Cc: Arnaldo Carvalho de Melo Cc: Ingo Molnar Cc: Jiri Olsa Cc: Peter Zijlstra Cc: Paul Mackerras Cc: Adrian Hunter Cc: David Ahern Cc: Frederic Weisbecker Cc: Namhyung Kim Cc: Stephane Eranian Cc: William Cohen Link: http://lkml.kernel.org/r/1406908014-8312-1-git-send-email-jolsa@kernel.org Reported-by: Jiri Olsa Signed-off-by: Yann Droneaud --- tools/perf/util/cloexec.c | 24 +++++++++++++----------- 1 file changed, 13 insertions(+), 11 deletions(-) diff --git a/tools/perf/util/cloexec.c b/tools/perf/util/cloexec.c index c5d05ec17220..dc360ebde745 100644 --- a/tools/perf/util/cloexec.c +++ b/tools/perf/util/cloexec.c @@ -13,34 +13,36 @@ static int perf_flag_probe(void) .config = PERF_COUNT_SW_CPU_CLOCK, }; int fd; - int err; + int err0, err1; /* check cloexec flag */ fd = sys_perf_event_open(&attr, 0, -1, -1, PERF_FLAG_FD_CLOEXEC); - err = errno; + err0 = errno; if (fd >= 0) { close(fd); return 1; } - WARN_ONCE(err != EINVAL, + WARN_ONCE(err0 != EINVAL, "perf_event_open(..., PERF_FLAG_FD_CLOEXEC) failed with unexpected error %d (%s)\n", - err, strerror(err)); + err0, strerror(err0)); /* not supported, confirm error related to PERF_FLAG_FD_CLOEXEC */ fd = sys_perf_event_open(&attr, 0, -1, -1, 0); - err = errno; + err1 = errno; - if (WARN_ONCE(fd < 0, - "perf_event_open(..., 0) failed unexpectedly with error %d (%s)\n", - err, strerror(err))) - return -1; + if (fd >= 0) { + close(fd); + return 0; + } - close(fd); + WARN_ONCE(err0 != err1, + "perf_event_open(..., 0) failed unexpectedly with error %d (%s)\n", + err1, strerror(err1)); - return 0; + return -1; } unsigned long perf_event_open_cloexec_flag(void) -- 1.9.3