From: Song Liu Date: Fri, 7 Apr 2023 19:01:30 +0000 (-0700) Subject: selftests/bpf: Use PERF_COUNT_HW_CPU_CYCLES event for get_branch_snapshot X-Git-Url: http://git.maquefel.me/?a=commitdiff_plain;h=3ebf5212bf042954666b19fe4ff5a98911b08128;p=linux.git selftests/bpf: Use PERF_COUNT_HW_CPU_CYCLES event for get_branch_snapshot perf_event with type=PERF_TYPE_RAW and config=0x1b00 turned out to be not reliable in ensuring LBR is active. Thus, test_progs:get_branch_snapshot is not reliable in some systems. Replace it with PERF_COUNT_HW_CPU_CYCLES event, which gives more consistent results. Signed-off-by: Song Liu Signed-off-by: Andrii Nakryiko Acked-by: Jiri Olsa Link: https://lore.kernel.org/bpf/20230407190130.2093736-1-song@kernel.org --- diff --git a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c index 3948da12a5284..0394a1156d99d 100644 --- a/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c +++ b/tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c @@ -37,8 +37,8 @@ static int create_perf_events(void) /* create perf event */ attr.size = sizeof(attr); - attr.type = PERF_TYPE_RAW; - attr.config = 0x1b00; + attr.type = PERF_TYPE_HARDWARE; + attr.config = PERF_COUNT_HW_CPU_CYCLES; attr.sample_type = PERF_SAMPLE_BRANCH_STACK; attr.branch_sample_type = PERF_SAMPLE_BRANCH_KERNEL | PERF_SAMPLE_BRANCH_USER | PERF_SAMPLE_BRANCH_ANY;