Commit-ID: e7bd9ba20a9ec7024a0566a93c22b9571a48939a Gitweb: http://git.kernel.org/tip/e7bd9ba20a9ec7024a0566a93c22b9571a48939a Author: Namhyung Kim <namhy...@kernel.org> AuthorDate: Sun, 18 Jun 2017 23:22:59 +0900 Committer: Arnaldo Carvalho de Melo <a...@redhat.com> CommitDate: Mon, 19 Jun 2017 22:05:51 -0300
perf ftrace: Show error message when fails to set ftrace files 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 <namhy...@kernel.org> Cc: Frederic Weisbecker <fweis...@gmail.com> Cc: Jiri Olsa <jo...@kernel.org> Cc: Masami Hiramatsu <mhira...@kernel.org> Cc: Peter Zijlstra <pet...@infradead.org> Cc: Steven Rostedt <rost...@goodmis.org> Cc: kernel-t...@lge.com Link: http://lkml.kernel.org/r/20170618142302.25390-1-namhy...@kernel.org Signed-off-by: Arnaldo Carvalho de Melo <a...@redhat.com> --- 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 9e0b35c..966a94f 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:
