path: root/tools/testing
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authorYonghong Song <yhs@fb.com>2020-01-16 09:40:04 -0800
committerAlexei Starovoitov <ast@kernel.org>2020-01-16 13:28:57 -0800
commit35697c12d7ffd31a56d3c9604066a166b75d0169 (patch)
tree959a081af0c6533335d84f7615b1911fd1911f09 /tools/testing
parentlibbpf: Fix unneeded extra initialization in bpf_map_batch_common (diff)
selftests/bpf: Fix test_progs send_signal flakiness with nmi mode
Alexei observed that test_progs send_signal may fail if run with command line "./test_progs" and the tests will pass if just run "./test_progs -n 40". I observed similar issue with nmi subtest failure and added a delay 100 us in Commit ab8b7f0cb358 ("tools/bpf: Add self tests for bpf_send_signal_thread()") and the problem is gone for me. But the issue still exists in Alexei's testing environment. The current code uses sample_freq = 50 (50 events/second), which may not be enough. But if the sample_freq value is larger than sysctl kernel/perf_event_max_sample_rate, the perf_event_open syscall will fail. This patch changed nmi perf testing to use sample_period = 1, which means trying to sampling every event. This seems fixing the issue. Fixes: ab8b7f0cb358 ("tools/bpf: Add self tests for bpf_send_signal_thread()") Signed-off-by: Yonghong Song <yhs@fb.com> Signed-off-by: Alexei Starovoitov <ast@kernel.org> Acked-by: Andrii Nakryiko <andriin@fb.com> Link: https://lore.kernel.org/bpf/20200116174004.1522812-1-yhs@fb.com
Diffstat (limited to 'tools/testing')
1 files changed, 1 insertions, 5 deletions
diff --git a/tools/testing/selftests/bpf/prog_tests/send_signal.c b/tools/testing/selftests/bpf/prog_tests/send_signal.c
index d4cedd86c424..504abb7bfb95 100644
--- a/tools/testing/selftests/bpf/prog_tests/send_signal.c
+++ b/tools/testing/selftests/bpf/prog_tests/send_signal.c
@@ -76,9 +76,6 @@ static void test_send_signal_common(struct perf_event_attr *attr,
if (CHECK(!skel, "skel_open_and_load", "skeleton open_and_load failed\n"))
goto skel_open_load_failure;
- /* add a delay for child thread to ramp up */
- usleep(100);
if (!attr) {
err = test_send_signal_kern__attach(skel);
if (CHECK(err, "skel_attach", "skeleton attach failed\n")) {
@@ -155,8 +152,7 @@ static void test_send_signal_perf(bool signal_thread)
static void test_send_signal_nmi(bool signal_thread)
struct perf_event_attr attr = {
- .sample_freq = 50,
- .freq = 1,
+ .sample_period = 1,