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| author |   Song Liu <songliubraving@fb.com> | 2021-09-10 11:33:51 -0700 |
|---|---|---|
| committer |   Alexei Starovoitov <ast@kernel.org> | 2021-09-13 10:53:50 -0700 |
| commit | 856c02dbce4f8d6a5644083db22c11750aa11481 (patch) | |
| tree | 3c3230ddfc3a5e7a03b30614b3da5aa2cc6cfe86 /tools/testing/selftests/bpf/test_progs.c | |
| parent | perf: Enable branch record for software events (diff) | |
| download | linux-dev-856c02dbce4f8d6a5644083db22c11750aa11481.tar.xz linux-dev-856c02dbce4f8d6a5644083db22c11750aa11481.zip | |
bpf: Introduce helper bpf_get_branch_snapshot
Introduce bpf_get_branch_snapshot(), which allows tracing pogram to get
branch trace from hardware (e.g. Intel LBR). To use the feature, the
user need to create perf_event with proper branch_record filtering
on each cpu, and then calls bpf_get_branch_snapshot in the bpf function.
On Intel CPUs, VLBR event (raw event 0x1b00) can be use for this.
Signed-off-by: Song Liu <songliubraving@fb.com>
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Acked-by: John Fastabend <john.fastabend@gmail.com>
Acked-by: Andrii Nakryiko <andrii@kernel.org>
Link: https://lore.kernel.org/bpf/20210910183352.3151445-3-songliubraving@fb.com
Diffstat (limited to 'tools/testing/selftests/bpf/test_progs.c')
0 files changed, 0 insertions, 0 deletions