From 9b190f185d2f6d65b4c16074db0c4eafa32c7ae1 Mon Sep 17 00:00:00 2001 From: Andrii Nakryiko Date: Sat, 6 Jul 2019 11:06:27 -0700 Subject: [PATCH] tools/bpftool: switch map event_pipe to libbpf's perf_buffer Switch event_pipe implementation to rely on new libbpf perf buffer API (it's raw low-level variant). Signed-off-by: Andrii Nakryiko Acked-by: Jakub Kicinski Acked-by: Yonghong Song Signed-off-by: Daniel Borkmann --- tools/bpf/bpftool/map_perf_ring.c | 201 ++++++++++-------------------- 1 file changed, 64 insertions(+), 137 deletions(-) diff --git a/tools/bpf/bpftool/map_perf_ring.c b/tools/bpf/bpftool/map_perf_ring.c index 0507dfaf7a8f..3f108ab17797 100644 --- a/tools/bpf/bpftool/map_perf_ring.c +++ b/tools/bpf/bpftool/map_perf_ring.c @@ -28,7 +28,7 @@ #define MMAP_PAGE_CNT 16 -static bool stop; +static volatile bool stop; struct event_ring_info { int fd; @@ -44,32 +44,44 @@ struct perf_event_sample { unsigned char data[]; }; +struct perf_event_lost { + struct perf_event_header header; + __u64 id; + __u64 lost; +}; + static void int_exit(int signo) { fprintf(stderr, "Stopping...\n"); stop = true; } +struct event_pipe_ctx { + bool all_cpus; + int cpu; + int idx; +}; + static enum bpf_perf_event_ret -print_bpf_output(struct perf_event_header *event, void *private_data) +print_bpf_output(void *private_data, int cpu, struct perf_event_header *event) { - struct perf_event_sample *e = container_of(event, struct perf_event_sample, + struct perf_event_sample *e = container_of(event, + struct perf_event_sample, header); - struct event_ring_info *ring = private_data; - struct { - struct perf_event_header header; - __u64 id; - __u64 lost; - } *lost = (typeof(lost))event; + struct perf_event_lost *lost = container_of(event, + struct perf_event_lost, + header); + struct event_pipe_ctx *ctx = private_data; + int idx = ctx->all_cpus ? cpu : ctx->idx; if (json_output) { jsonw_start_object(json_wtr); jsonw_name(json_wtr, "type"); jsonw_uint(json_wtr, e->header.type); jsonw_name(json_wtr, "cpu"); - jsonw_uint(json_wtr, ring->cpu); + jsonw_uint(json_wtr, cpu); jsonw_name(json_wtr, "index"); - jsonw_uint(json_wtr, ring->key); + jsonw_uint(json_wtr, idx); if (e->header.type == PERF_RECORD_SAMPLE) { jsonw_name(json_wtr, "timestamp"); jsonw_uint(json_wtr, e->time); @@ -89,7 +101,7 @@ print_bpf_output(struct perf_event_header *event, void *private_data) if (e->header.type == PERF_RECORD_SAMPLE) { printf("== @%lld.%09lld CPU: %d index: %d =====\n", e->time / 1000000000ULL, e->time % 1000000000ULL, - ring->cpu, ring->key); + cpu, idx); fprint_hex(stdout, e->data, e->size, " "); printf("\n"); } else if (e->header.type == PERF_RECORD_LOST) { @@ -103,87 +115,25 @@ print_bpf_output(struct perf_event_header *event, void *private_data) return LIBBPF_PERF_EVENT_CONT; } -static void -perf_event_read(struct event_ring_info *ring, void **buf, size_t *buf_len) -{ - enum bpf_perf_event_ret ret; - - ret = bpf_perf_event_read_simple(ring->mem, - MMAP_PAGE_CNT * get_page_size(), - get_page_size(), buf, buf_len, - print_bpf_output, ring); - if (ret != LIBBPF_PERF_EVENT_CONT) { - fprintf(stderr, "perf read loop failed with %d\n", ret); - stop = true; - } -} - -static int perf_mmap_size(void) -{ - return get_page_size() * (MMAP_PAGE_CNT + 1); -} - -static void *perf_event_mmap(int fd) -{ - int mmap_size = perf_mmap_size(); - void *base; - - base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0); - if (base == MAP_FAILED) { - p_err("event mmap failed: %s\n", strerror(errno)); - return NULL; - } - - return base; -} - -static void perf_event_unmap(void *mem) -{ - if (munmap(mem, perf_mmap_size())) - fprintf(stderr, "Can't unmap ring memory!\n"); -} - -static int bpf_perf_event_open(int map_fd, int key, int cpu) +int do_event_pipe(int argc, char **argv) { - struct perf_event_attr attr = { + struct perf_event_attr perf_attr = { .sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_TIME, .type = PERF_TYPE_SOFTWARE, .config = PERF_COUNT_SW_BPF_OUTPUT, + .sample_period = 1, + .wakeup_events = 1, }; - int pmu_fd; - - pmu_fd = sys_perf_event_open(&attr, -1, cpu, -1, 0); - if (pmu_fd < 0) { - p_err("failed to open perf event %d for CPU %d", key, cpu); - return -1; - } - - if (bpf_map_update_elem(map_fd, &key, &pmu_fd, BPF_ANY)) { - p_err("failed to update map for event %d for CPU %d", key, cpu); - goto err_close; - } - if (ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0)) { - p_err("failed to enable event %d for CPU %d", key, cpu); - goto err_close; - } - - return pmu_fd; - -err_close: - close(pmu_fd); - return -1; -} - -int do_event_pipe(int argc, char **argv) -{ - int i, nfds, map_fd, index = -1, cpu = -1; struct bpf_map_info map_info = {}; - struct event_ring_info *rings; - size_t tmp_buf_sz = 0; - void *tmp_buf = NULL; - struct pollfd *pfds; + struct perf_buffer_raw_opts opts = {}; + struct event_pipe_ctx ctx = { + .all_cpus = true, + .cpu = -1, + .idx = -1, + }; + struct perf_buffer *pb; __u32 map_info_len; - bool do_all = true; + int err, map_fd; map_info_len = sizeof(map_info); map_fd = map_parse_fd_and_info(&argc, &argv, &map_info, &map_info_len); @@ -205,7 +155,7 @@ int do_event_pipe(int argc, char **argv) char *endptr; NEXT_ARG(); - cpu = strtoul(*argv, &endptr, 0); + ctx.cpu = strtoul(*argv, &endptr, 0); if (*endptr) { p_err("can't parse %s as CPU ID", **argv); goto err_close_map; @@ -216,7 +166,7 @@ int do_event_pipe(int argc, char **argv) char *endptr; NEXT_ARG(); - index = strtoul(*argv, &endptr, 0); + ctx.idx = strtoul(*argv, &endptr, 0); if (*endptr) { p_err("can't parse %s as index", **argv); goto err_close_map; @@ -228,45 +178,32 @@ int do_event_pipe(int argc, char **argv) goto err_close_map; } - do_all = false; + ctx.all_cpus = false; } - if (!do_all) { - if (index == -1 || cpu == -1) { + if (!ctx.all_cpus) { + if (ctx.idx == -1 || ctx.cpu == -1) { p_err("cpu and index must be specified together"); goto err_close_map; } - - nfds = 1; } else { - nfds = min(get_possible_cpus(), map_info.max_entries); - cpu = 0; - index = 0; + ctx.cpu = 0; + ctx.idx = 0; } - rings = calloc(nfds, sizeof(rings[0])); - if (!rings) + opts.attr = &perf_attr; + opts.event_cb = print_bpf_output; + opts.ctx = &ctx; + opts.cpu_cnt = ctx.all_cpus ? 0 : 1; + opts.cpus = &ctx.cpu; + opts.map_keys = &ctx.idx; + + pb = perf_buffer__new_raw(map_fd, MMAP_PAGE_CNT, &opts); + err = libbpf_get_error(pb); + if (err) { + p_err("failed to create perf buffer: %s (%d)", + strerror(err), err); goto err_close_map; - - pfds = calloc(nfds, sizeof(pfds[0])); - if (!pfds) - goto err_free_rings; - - for (i = 0; i < nfds; i++) { - rings[i].cpu = cpu + i; - rings[i].key = index + i; - - rings[i].fd = bpf_perf_event_open(map_fd, rings[i].key, - rings[i].cpu); - if (rings[i].fd < 0) - goto err_close_fds_prev; - - rings[i].mem = perf_event_mmap(rings[i].fd); - if (!rings[i].mem) - goto err_close_fds_current; - - pfds[i].fd = rings[i].fd; - pfds[i].events = POLLIN; } signal(SIGINT, int_exit); @@ -277,34 +214,24 @@ int do_event_pipe(int argc, char **argv) jsonw_start_array(json_wtr); while (!stop) { - poll(pfds, nfds, 200); - for (i = 0; i < nfds; i++) - perf_event_read(&rings[i], &tmp_buf, &tmp_buf_sz); + err = perf_buffer__poll(pb, 200); + if (err < 0 && err != -EINTR) { + p_err("perf buffer polling failed: %s (%d)", + strerror(err), err); + goto err_close_pb; + } } - free(tmp_buf); if (json_output) jsonw_end_array(json_wtr); - for (i = 0; i < nfds; i++) { - perf_event_unmap(rings[i].mem); - close(rings[i].fd); - } - free(pfds); - free(rings); + perf_buffer__free(pb); close(map_fd); return 0; -err_close_fds_prev: - while (i--) { - perf_event_unmap(rings[i].mem); -err_close_fds_current: - close(rings[i].fd); - } - free(pfds); -err_free_rings: - free(rings); +err_close_pb: + perf_buffer__free(pb); err_close_map: close(map_fd); return -1; -- 2.30.2