[tip:perf/urgent] perf tests mmap: Show which tracepoint is failing

[tip-bot for Arnaldo Carvalho de Melo]

Commit-ID:  518c6021e9b82696819b380cd173e76cac55a01e
Gitweb:     https://git.kernel.org/tip/518c6021e9b82696819b380cd173e76cac55a01e
Author:     Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
AuthorDate: Tue, 17 Apr 2018 14:47:36 -0300
Committer:  Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
CommitDate: Wed, 18 Apr 2018 15:35:52 -0300

perf tests mmap: Show which tracepoint is failing

In the 'perf test "mmap interface"' we try creating events for several
tracepoints, but when perf_evsel__new() fails we're not showing which
one is failing, fix that to help diagnosing problems, such as the
syscall tracepoints ones being found and fixes in this merge window.

Now the failing tests shows:

  # perf test -v "mmap interface"
 4: Read samples using the mmap interface                 :
  --- start ---
  test child forked, pid 14311
  <SNIP>
  perf_evsel__new(sys_enter_getppid)
  test child finished with -1
  ---- end ----
  Read samples using the mmap interface: FAILED!
  #

Now to check why the syscalls:sys_enter_getppid is failing...

  # ls -la /sys/kernel/debug/tracing/events/syscalls/sys_enter_getppid
  ls: cannot access '/sys/kernel/debug/tracing/events/syscalls/sys_enter_getppid': No such file or directory
  #

Cc: Adrian Hunter <adrian.hunter@xxxxxxxxx>
Cc: David Ahern <dsahern@xxxxxxxxx>
Cc: Dominik Brodowski <linux@xxxxxxxxxxxxxxxxxxxx>
Cc: Jiri Olsa <jolsa@xxxxxxxxxx>
Cc: Namhyung Kim <namhyung@xxxxxxxxxx>
Cc: Steven Rostedt <rostedt@xxxxxxxxxxx>
Cc: Wang Nan <wangnan0@xxxxxxxxxx>
Link: https://lkml.kernel.org/n/tip-44xk0ycdzrfzx1o9rklf5itl@xxxxxxxxxxxxxx
Signed-off-by: Arnaldo Carvalho de Melo <acme@xxxxxxxxxx>
---
 tools/perf/tests/mmap-basic.c | 2 +-
 1 file changed, 1 insertion(+), 1 deletion(-)

diff --git a/tools/perf/tests/mmap-basic.c b/tools/perf/tests/mmap-basic.c
index bb8e6bcb0d96..0919b0793e5b 100644
--- a/tools/perf/tests/mmap-basic.c
+++ b/tools/perf/tests/mmap-basic.c
@@ -75,7 +75,7 @@ int test__basic_mmap(struct test *test __maybe_unused, int subtest __maybe_unuse
 		snprintf(name, sizeof(name), "sys_enter_%s", syscall_names[i]);
 		evsels[i] = perf_evsel__newtp("syscalls", name);
 		if (IS_ERR(evsels[i])) {
-			pr_debug("perf_evsel__new\n");
+			pr_debug("perf_evsel__new(%s)\n", name);
 			goto out_delete_evlist;
 		}