On 2024/4/1 23:29, Yonghong Song wrote:
On 4/1/24 5:33 AM, Pu Lehui wrote:
From: Pu Lehui <pulehui@xxxxxxxxxx>
For the bpf selftest, the semantics of perf_event_open returning ENOENT
and EOPNOTSUPP imply that continuing the test is meaningless. Let’s skip
test when perf_event_open returns EOPNOTSUPP, which has already been
skipped in other test cases.
Could you explain when EOPNOTSUPP is returned for these two tests?
Is this riscv specific? If the EOPNOTSUPP is returned due to missing
config in tools/testing/selftests/bpf/config, we should add that to
ensure the test can execute properly.
Hello Yonghong, I tested on riscv but it is not unique to riscv. When
the perf driver does not support sampling events, perf_event_open will
return EOPNOTSUPP, that is, PERF_PMU_CAP_NO_INTERRUPT is set to the pmu
capabilities. This is no problem with riscv with sscofpmf extension and
sbi pmu driver. I found that PERF_PMU_CAP_NO_INTERRUPT is set not only
in the riscv-related perf driver. At the same time, it is possible to
return EOPNOTSUPP about PERF_PMU_CAP_AUX_OUTPUT on the path of
perf_event_open. I think it resonable to skip such use cases for
functions not supported by non-bpf modules, what do you think?
Signed-off-by: Pu Lehui <pulehui@xxxxxxxxxx>
---
tools/testing/selftests/bpf/prog_tests/send_signal.c | 2 +-
.../testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c | 2 +-
2 files changed, 2 insertions(+), 2 deletions(-)
diff --git a/tools/testing/selftests/bpf/prog_tests/send_signal.c
b/tools/testing/selftests/bpf/prog_tests/send_signal.c
index b15b343ebb6b..920aee41bd58 100644
--- a/tools/testing/selftests/bpf/prog_tests/send_signal.c
+++ b/tools/testing/selftests/bpf/prog_tests/send_signal.c
@@ -179,7 +179,7 @@ static void test_send_signal_nmi(bool signal_thread)
pmu_fd = syscall(__NR_perf_event_open, &attr, 0 /* pid */,
-1 /* cpu */, -1 /* group_fd */, 0 /* flags */);
if (pmu_fd == -1) {
- if (errno == ENOENT) {
+ if (errno == ENOENT || errno == EOPNOTSUPP) {
printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n",
__func__);
test__skip();
diff --git
a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
index 5db9eec24b5b..0832fd787457 100644
--- a/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
+++ b/tools/testing/selftests/bpf/prog_tests/stacktrace_build_id_nmi.c
@@ -35,7 +35,7 @@ void test_stacktrace_build_id_nmi(void)
pmu_fd = syscall(__NR_perf_event_open, &attr, -1 /* pid */,
0 /* cpu 0 */, -1 /* group id */,
0 /* flags */);
- if (pmu_fd < 0 && errno == ENOENT) {
+ if (pmu_fd < 0 && (errno == ENOENT || errno == EOPNOTSUPP)) {
printf("%s:SKIP:no PERF_COUNT_HW_CPU_CYCLES\n", __func__);
test__skip();
goto cleanup;
