On Fri, Apr 07, 2023 at 12:01:30PM -0700, Song Liu wrote: > 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 <song@xxxxxxxxxx> Acked-by: Jiri Olsa <jolsa@xxxxxxxxxx> jirka > --- > tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c | 4 ++-- > 1 file changed, 2 insertions(+), 2 deletions(-) > > 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 3948da12a528..0394a1156d99 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; > -- > 2.34.1 >
