1 // SPDX-License-Identifier: GPL-2.0-only
2 /* Copyright (C) 2018 Netronome Systems, Inc. */
3 /* This program is free software; you can redistribute it and/or
4 * modify it under the terms of version 2 of the GNU General Public
5 * License as published by the Free Software Foundation.
18 #include <linux/bpf.h>
19 #include <linux/perf_event.h>
20 #include <sys/ioctl.h>
22 #include <sys/syscall.h>
29 #define MMAP_PAGE_CNT 16
33 struct event_ring_info {
40 struct perf_event_sample {
41 struct perf_event_header header;
47 static void int_exit(int signo)
49 fprintf(stderr, "Stopping...\n");
53 static enum bpf_perf_event_ret print_bpf_output(void *event, void *priv)
55 struct event_ring_info *ring = priv;
56 struct perf_event_sample *e = event;
58 struct perf_event_header header;
64 jsonw_start_object(json_wtr);
65 jsonw_name(json_wtr, "type");
66 jsonw_uint(json_wtr, e->header.type);
67 jsonw_name(json_wtr, "cpu");
68 jsonw_uint(json_wtr, ring->cpu);
69 jsonw_name(json_wtr, "index");
70 jsonw_uint(json_wtr, ring->key);
71 if (e->header.type == PERF_RECORD_SAMPLE) {
72 jsonw_name(json_wtr, "timestamp");
73 jsonw_uint(json_wtr, e->time);
74 jsonw_name(json_wtr, "data");
75 print_data_json(e->data, e->size);
76 } else if (e->header.type == PERF_RECORD_LOST) {
77 jsonw_name(json_wtr, "lost");
78 jsonw_start_object(json_wtr);
79 jsonw_name(json_wtr, "id");
80 jsonw_uint(json_wtr, lost->id);
81 jsonw_name(json_wtr, "count");
82 jsonw_uint(json_wtr, lost->lost);
83 jsonw_end_object(json_wtr);
85 jsonw_end_object(json_wtr);
87 if (e->header.type == PERF_RECORD_SAMPLE) {
88 printf("== @%lld.%09lld CPU: %d index: %d =====\n",
89 e->time / 1000000000ULL, e->time % 1000000000ULL,
90 ring->cpu, ring->key);
91 fprint_hex(stdout, e->data, e->size, " ");
93 } else if (e->header.type == PERF_RECORD_LOST) {
94 printf("lost %lld events\n", lost->lost);
96 printf("unknown event type=%d size=%d\n",
97 e->header.type, e->header.size);
101 return LIBBPF_PERF_EVENT_CONT;
105 perf_event_read(struct event_ring_info *ring, void **buf, size_t *buf_len)
107 enum bpf_perf_event_ret ret;
109 ret = bpf_perf_event_read_simple(ring->mem,
110 MMAP_PAGE_CNT * get_page_size(),
111 get_page_size(), buf, buf_len,
112 print_bpf_output, ring);
113 if (ret != LIBBPF_PERF_EVENT_CONT) {
114 fprintf(stderr, "perf read loop failed with %d\n", ret);
119 static int perf_mmap_size(void)
121 return get_page_size() * (MMAP_PAGE_CNT + 1);
124 static void *perf_event_mmap(int fd)
126 int mmap_size = perf_mmap_size();
129 base = mmap(NULL, mmap_size, PROT_READ | PROT_WRITE, MAP_SHARED, fd, 0);
130 if (base == MAP_FAILED) {
131 p_err("event mmap failed: %s\n", strerror(errno));
138 static void perf_event_unmap(void *mem)
140 if (munmap(mem, perf_mmap_size()))
141 fprintf(stderr, "Can't unmap ring memory!\n");
144 static int bpf_perf_event_open(int map_fd, int key, int cpu)
146 struct perf_event_attr attr = {
147 .sample_type = PERF_SAMPLE_RAW | PERF_SAMPLE_TIME,
148 .type = PERF_TYPE_SOFTWARE,
149 .config = PERF_COUNT_SW_BPF_OUTPUT,
153 pmu_fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
155 p_err("failed to open perf event %d for CPU %d", key, cpu);
159 if (bpf_map_update_elem(map_fd, &key, &pmu_fd, BPF_ANY)) {
160 p_err("failed to update map for event %d for CPU %d", key, cpu);
163 if (ioctl(pmu_fd, PERF_EVENT_IOC_ENABLE, 0)) {
164 p_err("failed to enable event %d for CPU %d", key, cpu);
175 int do_event_pipe(int argc, char **argv)
177 int i, nfds, map_fd, index = -1, cpu = -1;
178 struct bpf_map_info map_info = {};
179 struct event_ring_info *rings;
180 size_t tmp_buf_sz = 0;
181 void *tmp_buf = NULL;
186 map_info_len = sizeof(map_info);
187 map_fd = map_parse_fd_and_info(&argc, &argv, &map_info, &map_info_len);
191 if (map_info.type != BPF_MAP_TYPE_PERF_EVENT_ARRAY) {
192 p_err("map is not a perf event array");
202 if (is_prefix(*argv, "cpu")) {
206 cpu = strtoul(*argv, &endptr, 0);
208 p_err("can't parse %s as CPU ID", **argv);
213 } else if (is_prefix(*argv, "index")) {
217 index = strtoul(*argv, &endptr, 0);
219 p_err("can't parse %s as index", **argv);
233 if (index == -1 || cpu == -1) {
234 p_err("cpu and index must be specified together");
240 nfds = min(get_possible_cpus(), map_info.max_entries);
245 rings = calloc(nfds, sizeof(rings[0]));
249 pfds = calloc(nfds, sizeof(pfds[0]));
253 for (i = 0; i < nfds; i++) {
254 rings[i].cpu = cpu + i;
255 rings[i].key = index + i;
257 rings[i].fd = bpf_perf_event_open(map_fd, rings[i].key,
260 goto err_close_fds_prev;
262 rings[i].mem = perf_event_mmap(rings[i].fd);
264 goto err_close_fds_current;
266 pfds[i].fd = rings[i].fd;
267 pfds[i].events = POLLIN;
270 signal(SIGINT, int_exit);
271 signal(SIGHUP, int_exit);
272 signal(SIGTERM, int_exit);
275 jsonw_start_array(json_wtr);
278 poll(pfds, nfds, 200);
279 for (i = 0; i < nfds; i++)
280 perf_event_read(&rings[i], &tmp_buf, &tmp_buf_sz);
285 jsonw_end_array(json_wtr);
287 for (i = 0; i < nfds; i++) {
288 perf_event_unmap(rings[i].mem);
299 perf_event_unmap(rings[i].mem);
300 err_close_fds_current: