diff options
| -rw-r--r-- | tools/lib/bpf/libbpf.c | 56 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.h | 4 | ||||
| -rw-r--r-- | tools/lib/bpf/libbpf.map | 8 | ||||
| -rw-r--r-- | tools/testing/selftests/bpf/prog_tests/perf_buffer.c | 65 |
4 files changed, 121 insertions, 12 deletions
diff --git a/tools/lib/bpf/libbpf.c b/tools/lib/bpf/libbpf.c index 0bc1fd813408..210429c5b772 100644 --- a/tools/lib/bpf/libbpf.c +++ b/tools/lib/bpf/libbpf.c @@ -9373,6 +9373,11 @@ static int perf_buffer__process_records(struct perf_buffer *pb, return 0; } +int perf_buffer__epoll_fd(const struct perf_buffer *pb) +{ + return pb->epoll_fd; +} + int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms) { int i, cnt, err; @@ -9390,6 +9395,55 @@ int perf_buffer__poll(struct perf_buffer *pb, int timeout_ms) return cnt < 0 ? -errno : cnt; } +/* Return number of PERF_EVENT_ARRAY map slots set up by this perf_buffer + * manager. + */ +size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb) +{ + return pb->cpu_cnt; +} + +/* + * Return perf_event FD of a ring buffer in *buf_idx* slot of + * PERF_EVENT_ARRAY BPF map. This FD can be polled for new data using + * select()/poll()/epoll() Linux syscalls. + */ +int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx) +{ + struct perf_cpu_buf *cpu_buf; + + if (buf_idx >= pb->cpu_cnt) + return -EINVAL; + + cpu_buf = pb->cpu_bufs[buf_idx]; + if (!cpu_buf) + return -ENOENT; + + return cpu_buf->fd; +} + +/* + * Consume data from perf ring buffer corresponding to slot *buf_idx* in + * PERF_EVENT_ARRAY BPF map without waiting/polling. If there is no data to + * consume, do nothing and return success. + * Returns: + * - 0 on success; + * - <0 on failure. + */ +int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx) +{ + struct perf_cpu_buf *cpu_buf; + + if (buf_idx >= pb->cpu_cnt) + return -EINVAL; + + cpu_buf = pb->cpu_bufs[buf_idx]; + if (!cpu_buf) + return -ENOENT; + + return perf_buffer__process_records(pb, cpu_buf); +} + int perf_buffer__consume(struct perf_buffer *pb) { int i, err; @@ -9402,7 +9456,7 @@ int perf_buffer__consume(struct perf_buffer *pb) err = perf_buffer__process_records(pb, cpu_buf); if (err) { - pr_warn("error while processing records: %d\n", err); + pr_warn("perf_buffer: failed to process records in buffer #%d: %d\n", i, err); return err; } } diff --git a/tools/lib/bpf/libbpf.h b/tools/lib/bpf/libbpf.h index 5ecb4069a9f0..308e0ded8f14 100644 --- a/tools/lib/bpf/libbpf.h +++ b/tools/lib/bpf/libbpf.h @@ -588,8 +588,12 @@ perf_buffer__new_raw(int map_fd, size_t page_cnt, const struct perf_buffer_raw_opts *opts); LIBBPF_API void perf_buffer__free(struct perf_buffer *pb); +LIBBPF_API int perf_buffer__epoll_fd(const 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); +LIBBPF_API int perf_buffer__consume_buffer(struct perf_buffer *pb, size_t buf_idx); +LIBBPF_API size_t perf_buffer__buffer_cnt(const struct perf_buffer *pb); +LIBBPF_API int perf_buffer__buffer_fd(const struct perf_buffer *pb, size_t buf_idx); 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 e35bd6cdbdbf..66a6286d0716 100644 --- a/tools/lib/bpf/libbpf.map +++ b/tools/lib/bpf/libbpf.map @@ -299,3 +299,11 @@ LIBBPF_0.1.0 { btf__set_fd; btf__set_pointer_size; } LIBBPF_0.0.9; + +LIBBPF_0.2.0 { + global: + perf_buffer__buffer_cnt; + perf_buffer__buffer_fd; + perf_buffer__epoll_fd; + perf_buffer__consume_buffer; +} LIBBPF_0.1.0; diff --git a/tools/testing/selftests/bpf/prog_tests/perf_buffer.c b/tools/testing/selftests/bpf/prog_tests/perf_buffer.c index c33ec180b3f2..ca9f0895ec84 100644 --- a/tools/testing/selftests/bpf/prog_tests/perf_buffer.c +++ b/tools/testing/selftests/bpf/prog_tests/perf_buffer.c @@ -7,6 +7,8 @@ #include "test_perf_buffer.skel.h" #include "bpf/libbpf_internal.h" +static int duration; + /* AddressSanitizer sometimes crashes due to data dereference below, due to * this being mmap()'ed memory. Disable instrumentation with * no_sanitize_address attribute @@ -24,13 +26,31 @@ static void on_sample(void *ctx, int cpu, void *data, __u32 size) CPU_SET(cpu, cpu_seen); } +int trigger_on_cpu(int cpu) +{ + cpu_set_t cpu_set; + int err; + + CPU_ZERO(&cpu_set); + CPU_SET(cpu, &cpu_set); + + err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), &cpu_set); + if (err && CHECK(err, "set_affinity", "cpu #%d, err %d\n", cpu, err)) + return err; + + usleep(1); + + return 0; +} + void test_perf_buffer(void) { - int err, on_len, nr_on_cpus = 0, nr_cpus, i, duration = 0; + int err, on_len, nr_on_cpus = 0, nr_cpus, i; struct perf_buffer_opts pb_opts = {}; struct test_perf_buffer *skel; - cpu_set_t cpu_set, cpu_seen; + cpu_set_t cpu_seen; struct perf_buffer *pb; + int last_fd = -1, fd; bool *online; nr_cpus = libbpf_num_possible_cpus(); @@ -63,6 +83,9 @@ void test_perf_buffer(void) if (CHECK(IS_ERR(pb), "perf_buf__new", "err %ld\n", PTR_ERR(pb))) goto out_close; + CHECK(perf_buffer__epoll_fd(pb) < 0, "epoll_fd", + "bad fd: %d\n", perf_buffer__epoll_fd(pb)); + /* trigger kprobe on every CPU */ CPU_ZERO(&cpu_seen); for (i = 0; i < nr_cpus; i++) { @@ -71,16 +94,8 @@ void test_perf_buffer(void) continue; } - CPU_ZERO(&cpu_set); - CPU_SET(i, &cpu_set); - - err = pthread_setaffinity_np(pthread_self(), sizeof(cpu_set), - &cpu_set); - if (err && CHECK(err, "set_affinity", "cpu #%d, err %d\n", - i, err)) + if (trigger_on_cpu(i)) goto out_close; - - usleep(1); } /* read perf buffer */ @@ -92,6 +107,34 @@ void test_perf_buffer(void) "expect %d, seen %d\n", nr_on_cpus, CPU_COUNT(&cpu_seen))) goto out_free_pb; + if (CHECK(perf_buffer__buffer_cnt(pb) != nr_cpus, "buf_cnt", + "got %zu, expected %d\n", perf_buffer__buffer_cnt(pb), nr_cpus)) + goto out_close; + + for (i = 0; i < nr_cpus; i++) { + if (i >= on_len || !online[i]) + continue; + + fd = perf_buffer__buffer_fd(pb, i); + CHECK(fd < 0 || last_fd == fd, "fd_check", "last fd %d == fd %d\n", last_fd, fd); + last_fd = fd; + + err = perf_buffer__consume_buffer(pb, i); + if (CHECK(err, "drain_buf", "cpu %d, err %d\n", i, err)) + goto out_close; + + CPU_CLR(i, &cpu_seen); + if (trigger_on_cpu(i)) + goto out_close; + + err = perf_buffer__consume_buffer(pb, i); + if (CHECK(err, "consume_buf", "cpu %d, err %d\n", i, err)) + goto out_close; + + if (CHECK(!CPU_ISSET(i, &cpu_seen), "cpu_seen", "cpu %d not seen\n", i)) + goto out_close; + } + out_free_pb: perf_buffer__free(pb); out_close: |