Gracefully skip the test_perf_branches_hw subtest on platforms that do not support LBR or require specialized perf event attributes to enable branch sampling. For example, AMD's Milan (Zen 3) supports BRS rather than traditional LBR. This requires specific configurations (attr.type = PERF_TYPE_RAW, attr.config = RETIRED_TAKEN_BRANCH_INSTRUCTIONS) that differ from the generic setup used within this test. Notably, it also probably doesn't hold much value to special case perf event configurations for selected micro architectures. Fixes: 67306f84ca78c ("selftests/bpf: Add bpf_read_branch_records() selftest") Signed-off-by: Matt Bobrowski --- tools/testing/selftests/bpf/prog_tests/perf_branches.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) diff --git a/tools/testing/selftests/bpf/prog_tests/perf_branches.c b/tools/testing/selftests/bpf/prog_tests/perf_branches.c index 1d51ec5f171a..0a7ef770c487 100644 --- a/tools/testing/selftests/bpf/prog_tests/perf_branches.c +++ b/tools/testing/selftests/bpf/prog_tests/perf_branches.c @@ -128,11 +128,11 @@ static void test_perf_branches_hw(void) pfd = syscall(__NR_perf_event_open, &attr, -1, 0, -1, PERF_FLAG_FD_CLOEXEC); /* - * Some setups don't support branch records (virtual machines, !x86), - * so skip test in this case. + * Some setups don't support LBR (virtual machines, !x86, AMD Milan Zen + * 3 which only supports BRS), so skip test in this case. */ if (pfd < 0) { - if (errno == ENOENT || errno == EOPNOTSUPP) { + if (errno == ENOENT || errno == EOPNOTSUPP || errno == EINVAL) { printf("%s:SKIP:no PERF_SAMPLE_BRANCH_STACK\n", __func__); test__skip(); -- 2.52.0.rc1.455.g30608eb744-goog