From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753172AbdFROXj (ORCPT ); Sun, 18 Jun 2017 10:23:39 -0400 Received: from mail-pf0-f195.google.com ([209.85.192.195]:36558 "EHLO mail-pf0-f195.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752102AbdFROXh (ORCPT ); Sun, 18 Jun 2017 10:23:37 -0400 From: Namhyung Kim To: Arnaldo Carvalho de Melo Cc: Ingo Molnar , Peter Zijlstra , Jiri Olsa , LKML , kernel-team@lge.com, Masami Hiramatsu , Steven Rostedt , Frederic Weisbecker Subject: [PATCH 1/4] perf ftrace: Show error message when fails to set ftrace files Date: Sun, 18 Jun 2017 23:22:59 +0900 Message-Id: <20170618142302.25390-1-namhyung@kernel.org> X-Mailer: git-send-email 2.13.0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org It'd be better for debugging to show an error message when it fails to setup ftrace for some reason. Cc: Steven Rostedt Cc: Frederic Weisbecker Signed-off-by: Namhyung Kim --- 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: -- 2.13.0