From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752746Ab3JUGIA (ORCPT ); Mon, 21 Oct 2013 02:08:00 -0400 Received: from mga03.intel.com ([143.182.124.21]:47555 "EHLO mga03.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752280Ab3JUGH7 (ORCPT ); Mon, 21 Oct 2013 02:07:59 -0400 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="4.93,535,1378882800"; d="scan'208";a="377534206" Message-ID: <5264C494.9070003@intel.com> Date: Mon, 21 Oct 2013 09:07:16 +0300 From: Adrian Hunter Organization: Intel Finland Oy, Registered Address: PL 281, 00181 Helsinki, Business Identity Code: 0357606 - 4, Domiciled in Helsinki User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:17.0) Gecko/20130625 Thunderbird/17.0.7 MIME-Version: 1.0 To: Jiri Olsa CC: Arnaldo Carvalho de Melo , Peter Zijlstra , Ingo Molnar , linux-kernel@vger.kernel.org, David Ahern , Frederic Weisbecker , Mike Galbraith , Namhyung Kim , Paul Mackerras , Stephane Eranian Subject: Re: [PATCH 03/19] perf record: Improve write_output error message References: <1382099356-4918-1-git-send-email-adrian.hunter@intel.com> <1382099356-4918-4-git-send-email-adrian.hunter@intel.com> <20131020204316.GB12044@krava> In-Reply-To: <20131020204316.GB12044@krava> Content-Type: text/plain; charset=ISO-8859-1 Content-Transfer-Encoding: 7bit Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org On 20/10/13 23:43, Jiri Olsa wrote: > On Fri, Oct 18, 2013 at 03:29:00PM +0300, Adrian Hunter wrote: >> Improve the error message from write_output() to say >> what failed to write and give the error number. >> >> Signed-off-by: Adrian Hunter >> --- >> tools/perf/builtin-record.c | 2 +- >> 1 file changed, 1 insertion(+), 1 deletion(-) >> >> diff --git a/tools/perf/builtin-record.c b/tools/perf/builtin-record.c >> index 92ca541..d269dfa 100644 >> --- a/tools/perf/builtin-record.c >> +++ b/tools/perf/builtin-record.c >> @@ -88,7 +88,7 @@ static int write_output(struct perf_record *rec, void *buf, size_t size) >> int ret = write(rec->output, buf, size); >> >> if (ret < 0) { >> - pr_err("failed to write\n"); >> + pr_err("failed to write perf data, error: %m\n"); > > is this some kind of format magic? ;-) you wanted It is a glibc extension. > to print out 'ret' value, right? No, errno