| Message ID | 20230407190130.2093736-1-song@kernel.org (mailing list archive) |
|---|---|
| State | Accepted |
| Commit | 3ebf5212bf042954666b19fe4ff5a98911b08128 |
| Delegated to: | BPF |
| Headers | show |
| Series | [bpf-next] selftests/bpf: Use PERF_COUNT_HW_CPU_CYCLES event for get_branch_snapshot | expand |
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@kernel.org> Acked-by: Jiri Olsa <jolsa@kernel.org> 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 >
Hello: This patch was applied to bpf/bpf-next.git (master) by Andrii Nakryiko <andrii@kernel.org>: On Fri, 7 Apr 2023 12:01:30 -0700 you 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@kernel.org> > > [...] Here is the summary with links: - [bpf-next] selftests/bpf: Use PERF_COUNT_HW_CPU_CYCLES event for get_branch_snapshot https://git.kernel.org/bpf/bpf-next/c/3ebf5212bf04 You are awesome, thank you!
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;
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@kernel.org> --- tools/testing/selftests/bpf/prog_tests/get_branch_snapshot.c | 4 ++-- 1 file changed, 2 insertions(+), 2 deletions(-)