[PATCH 1/2] perf test: Silence tracepoint event failures

From: Namhyung Kim
Date: Mon Oct 19 2015 - 11:24:03 EST


Currently, when perf test is run by a normal user, it'll fail to access
tracepoint events. However the output is somewhat messy since it tries
to be nice with long error messages and hints. IMHO it's not needed
for 'perf test' by default and AFAIK the perf test uses pr_debug()
rather than pr_err() for such messages so that one can use -v option to
see further details on failed testcases if needed.

Before:
$ perf test
1: vmlinux symtab matches kallsyms : FAILED!
2: detect openat syscall event :Error:
No permissions to read
/sys/kernel/debug/tracing/events/syscalls/sys_enter_openat
Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'
FAILED!
3: detect openat syscall event on all cpus :Error:
No permissions to read
/sys/kernel/debug/tracing/events/syscalls/sys_enter_openat
Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'
FAILED!
...

After:
$ perf test
1: vmlinux symtab matches kallsyms : FAILED!
2: detect openat syscall event : FAILED!
3: detect openat syscall event on all cpus : FAILED!
...

$ perf test -v 2
2: detect openat syscall event :
--- start ---
test child forked, pid 30575
Error: No permissions to read
/sys/kernel/debug/tracing/events/syscalls/sys_enter_openat
Hint: Try 'sudo mount -o remount,mode=755 /sys/kernel/debug/tracing'

test child finished with -1
---- end ----
detect openat syscall event: FAILED!

Signed-off-by: Namhyung Kim <namhyung@xxxxxxxxxx>
---
tools/perf/tests/openat-syscall-all-cpus.c | 2 +-
tools/perf/tests/openat-syscall-tp-fields.c | 2 +-
tools/perf/tests/openat-syscall.c | 2 +-
3 files changed, 3 insertions(+), 3 deletions(-)

diff --git a/tools/perf/tests/openat-syscall-all-cpus.c b/tools/perf/tests/openat-syscall-all-cpus.c
index 9e104a2e973d..2006485a2859 100644
--- a/tools/perf/tests/openat-syscall-all-cpus.c
+++ b/tools/perf/tests/openat-syscall-all-cpus.c
@@ -34,7 +34,7 @@ int test__openat_syscall_event_on_all_cpus(void)
evsel = perf_evsel__newtp("syscalls", "sys_enter_openat");
if (IS_ERR(evsel)) {
tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "syscalls", "sys_enter_openat");
- pr_err("%s\n", errbuf);
+ pr_debug("%s\n", errbuf);
goto out_thread_map_delete;
}

diff --git a/tools/perf/tests/openat-syscall-tp-fields.c b/tools/perf/tests/openat-syscall-tp-fields.c
index 473d3869727e..5e811cd8f1c3 100644
--- a/tools/perf/tests/openat-syscall-tp-fields.c
+++ b/tools/perf/tests/openat-syscall-tp-fields.c
@@ -89,7 +89,7 @@ int test__syscall_openat_tp_fields(void)

err = perf_evsel__parse_sample(evsel, event, &sample);
if (err) {
- pr_err("Can't parse sample, err = %d\n", err);
+ pr_debug("Can't parse sample, err = %d\n", err);
goto out_delete_evlist;
}

diff --git a/tools/perf/tests/openat-syscall.c b/tools/perf/tests/openat-syscall.c
index 7b1db8306098..033b54797b8a 100644
--- a/tools/perf/tests/openat-syscall.c
+++ b/tools/perf/tests/openat-syscall.c
@@ -22,7 +22,7 @@ int test__openat_syscall_event(void)
evsel = perf_evsel__newtp("syscalls", "sys_enter_openat");
if (IS_ERR(evsel)) {
tracing_path__strerror_open_tp(errno, errbuf, sizeof(errbuf), "syscalls", "sys_enter_openat");
- pr_err("%s\n", errbuf);
+ pr_debug("%s\n", errbuf);
goto out_thread_map_delete;
}

--
2.6.0

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