From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1752528AbdFTB6Y (ORCPT ); Mon, 19 Jun 2017 21:58:24 -0400 Received: from mail.kernel.org ([198.145.29.99]:60646 "EHLO mail.kernel.org" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752464AbdFTB6M (ORCPT ); Mon, 19 Jun 2017 21:58:12 -0400 DMARC-Filter: OpenDMARC Filter v1.3.2 mail.kernel.org 88CB1239F0 Authentication-Results: mail.kernel.org; dmarc=none (p=none dis=none) header.from=kernel.org Authentication-Results: mail.kernel.org; spf=none smtp.mailfrom=acme@kernel.org From: Arnaldo Carvalho de Melo To: Ingo Molnar Cc: linux-kernel@vger.kernel.org, Namhyung Kim , Frederic Weisbecker , Jiri Olsa , Masami Hiramatsu , Peter Zijlstra , Steven Rostedt , kernel-team@lge.com, Arnaldo Carvalho de Melo Subject: [PATCH 18/23] perf ftrace: Show error message when fails to set ftrace files Date: Mon, 19 Jun 2017 22:54:54 -0300 Message-Id: <20170620015459.29381-19-acme@kernel.org> X-Mailer: git-send-email 2.9.4 In-Reply-To: <20170620015459.29381-1-acme@kernel.org> References: <20170620015459.29381-1-acme@kernel.org> Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org From: Namhyung Kim It'd be better for debugging to show an error message when it fails to setup ftrace for some reason. Signed-off-by: Namhyung Kim Cc: Frederic Weisbecker Cc: Jiri Olsa Cc: Masami Hiramatsu Cc: Peter Zijlstra Cc: Steven Rostedt Cc: kernel-team@lge.com Link: http://lkml.kernel.org/r/20170618142302.25390-1-namhyung@kernel.org Signed-off-by: Arnaldo Carvalho de Melo --- tools/perf/builtin-ftrace.c | 7 +++++-- 1 file changed, 5 insertions(+), 2 deletions(-) diff --git a/tools/perf/builtin-ftrace.c b/tools/perf/builtin-ftrace.c index 9e0b35cd0eea..966a94fa8200 100644 --- a/tools/perf/builtin-ftrace.c +++ b/tools/perf/builtin-ftrace.c @@ -61,6 +61,7 @@ static int __write_tracing_file(const char *name, const char *val, bool append) int fd, ret = -1; ssize_t size = strlen(val); int flags = O_WRONLY; + char errbuf[512]; file = get_tracing_file(name); if (!file) { @@ -75,14 +76,16 @@ static int __write_tracing_file(const char *name, const char *val, bool append) fd = open(file, flags); if (fd < 0) { - pr_debug("cannot open tracing file: %s\n", name); + pr_debug("cannot open tracing file: %s: %s\n", + name, str_error_r(errno, errbuf, sizeof(errbuf))); goto out; } if (write(fd, val, size) == size) ret = 0; else - pr_debug("write '%s' to tracing/%s failed\n", val, name); + pr_debug("write '%s' to tracing/%s failed: %s\n", + val, name, str_error_r(errno, errbuf, sizeof(errbuf))); close(fd); out: -- 2.9.4