diff options
| author | Eelco Chaudron <echaudro@redhat.com> | 2020-05-26 11:21:42 +0200 |
|---|---|---|
| committer | Alexei Starovoitov <ast@kernel.org> | 2020-06-01 14:38:19 -0700 |
| commit | 272d51af32890632134845ddf35318c11da20c7b (patch) | |
| tree | 2a0a27eb06b4c0b624d4bf7aa45deb9ffdf57798 /tools/lib | |
| parent | 2b983b407a3a1f47f7d8595245066854ff352c65 (diff) | |
libbpf: Add API to consume the perf ring buffer content
This new API, perf_buffer__consume, can be used as follows:
- When you have a perf ring where wakeup_events is higher than 1,
and you have remaining data in the rings you would like to pull
out on exit (or maybe based on a timeout).
- For low latency cases where you burn a CPU that constantly polls
the queues.
Signed-off-by: Eelco Chaudron <echaudro@redhat.com>
Signed-off-by: Daniel Borkmann <daniel@iogearbox.net>
Acked-by: Andrii Nakryiko <andriin@fb.com>
Link: https://lore.kernel.org/bpf/159048487929.89441.7465713173442594608.stgit@ebuild
Signed-off-by: Alexei Starovoitov <ast@kernel.org>
Diffstat (limited to 'tools/lib')
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 19 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.h | 1 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.map | 1 |
3 files changed, 21 insertions, 0 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index fa04cbe547ed..5d60de6fd818 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -8456,6 +8456,25 @@ int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms) return cnt < 0 ? -errno : cnt; } +int perf_buffer__consume(struct perf_buffer *pb) +{ + int i, err; + + for (i = 0; i < pb->cpu_cnt; i++) { + struct perf_cpu_buf *cpu_buf = pb->cpu_bufs[i]; + + if (!cpu_buf) + continue; + + err = perf_buffer__process_records(pb, cpu_buf); + if (err) { + pr_warn("error while processing records: %d\n", err); + return err; + } + } + return 0; +} + struct bpf_prog_info_array_desc { int array_offset; /* e.g. offset of jited_prog_insns */ int count_offset; /* e.g. offset of jited_prog_len */ diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 8ea69558f0a8..1e2e399a5f2c 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -533,6 +533,7 @@ perf_buffer__new_raw(int map_fd, size_t page_cnt, LIBBPF_API void perf_buffer__free(struct perf_buffer *pb); LIBBPF_API int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms); +LIBBPF_API int perf_buffer__consume(struct perf_buffer *pb); typedef enum bpf_perf_event_ret (*bpf_perf_event_print_t)(struct perf_event_header *hdr, diff --git a/tools/lib/bpf/libbpf.map b/tools/lib/bpf/libbpf.map index 0133d469d30b..381a7342ecfc 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -262,4 +262,5 @@ LIBBPF_0.0.9 { bpf_link_get_fd_by_id; bpf_link_get_next_id; bpf_program__attach_iter; + perf_buffer__consume; } LIBBPF_0.0.8; |