1 // SPDX-License-Identifier: GPL-2.0 2 3 /* Copyright (c) 2021 Facebook */ 4 /* Copyright (c) 2021 Google */ 5 6 #include <assert.h> 7 #include <limits.h> 8 #include <unistd.h> 9 #include <sys/file.h> 10 #include <sys/time.h> 11 #include <sys/resource.h> 12 #include <linux/err.h> 13 #include <linux/zalloc.h> 14 #include <linux/perf_event.h> 15 #include <api/fs/fs.h> 16 #include <perf/bpf_perf.h> 17 18 #include "affinity.h" 19 #include "bpf_counter.h" 20 #include "cgroup.h" 21 #include "counts.h" 22 #include "debug.h" 23 #include "evsel.h" 24 #include "evlist.h" 25 #include "target.h" 26 #include "cpumap.h" 27 #include "thread_map.h" 28 29 #include "bpf_skel/bperf_cgroup.skel.h" 30 31 static struct perf_event_attr cgrp_switch_attr = { 32 .type = PERF_TYPE_SOFTWARE, 33 .config = PERF_COUNT_SW_CGROUP_SWITCHES, 34 .size = sizeof(cgrp_switch_attr), 35 .sample_period = 1, 36 .disabled = 1, 37 }; 38 39 static struct evsel *cgrp_switch; 40 static struct bperf_cgroup_bpf *skel; 41 42 #define FD(evt, cpu) (*(int *)xyarray__entry(evt->core.fd, cpu, 0)) 43 44 static int bperf_load_program(struct evlist *evlist) 45 { 46 struct bpf_link *link; 47 struct evsel *evsel; 48 struct cgroup *cgrp, *leader_cgrp; 49 int i, j; 50 struct perf_cpu cpu; 51 int total_cpus = cpu__max_cpu().cpu; 52 int map_size, map_fd; 53 int prog_fd, err; 54 55 skel = bperf_cgroup_bpf__open(); 56 if (!skel) { 57 pr_err("Failed to open cgroup skeleton\n"); 58 return -1; 59 } 60 61 skel->rodata->num_cpus = total_cpus; 62 skel->rodata->num_events = evlist->core.nr_entries / nr_cgroups; 63 64 BUG_ON(evlist->core.nr_entries % nr_cgroups != 0); 65 66 /* we need one copy of events per cpu for reading */ 67 map_size = total_cpus * evlist->core.nr_entries / nr_cgroups; 68 bpf_map__set_max_entries(skel->maps.events, map_size); 69 bpf_map__set_max_entries(skel->maps.cgrp_idx, nr_cgroups); 70 /* previous result is saved in a per-cpu array */ 71 map_size = evlist->core.nr_entries / nr_cgroups; 72 bpf_map__set_max_entries(skel->maps.prev_readings, map_size); 73 /* cgroup result needs all events (per-cpu) */ 74 map_size = evlist->core.nr_entries; 75 bpf_map__set_max_entries(skel->maps.cgrp_readings, map_size); 76 77 set_max_rlimit(); 78 79 err = bperf_cgroup_bpf__load(skel); 80 if (err) { 81 pr_err("Failed to load cgroup skeleton\n"); 82 goto out; 83 } 84 85 if (cgroup_is_v2("perf_event") > 0) 86 skel->bss->use_cgroup_v2 = 1; 87 88 err = -1; 89 90 cgrp_switch = evsel__new(&cgrp_switch_attr); 91 if (evsel__open_per_cpu(cgrp_switch, evlist->core.all_cpus, -1) < 0) { 92 pr_err("Failed to open cgroup switches event\n"); 93 goto out; 94 } 95 96 perf_cpu_map__for_each_cpu(cpu, i, evlist->core.all_cpus) { 97 link = bpf_program__attach_perf_event(skel->progs.on_cgrp_switch, 98 FD(cgrp_switch, i)); 99 if (IS_ERR(link)) { 100 pr_err("Failed to attach cgroup program\n"); 101 err = PTR_ERR(link); 102 goto out; 103 } 104 } 105 106 /* 107 * Update cgrp_idx map from cgroup-id to event index. 108 */ 109 cgrp = NULL; 110 i = 0; 111 112 evlist__for_each_entry(evlist, evsel) { 113 if (cgrp == NULL || evsel->cgrp == leader_cgrp) { 114 leader_cgrp = evsel->cgrp; 115 evsel->cgrp = NULL; 116 117 /* open single copy of the events w/o cgroup */ 118 err = evsel__open_per_cpu(evsel, evsel->core.cpus, -1); 119 if (err) { 120 pr_err("Failed to open first cgroup events\n"); 121 goto out; 122 } 123 124 map_fd = bpf_map__fd(skel->maps.events); 125 perf_cpu_map__for_each_cpu(cpu, j, evsel->core.cpus) { 126 int fd = FD(evsel, j); 127 __u32 idx = evsel->core.idx * total_cpus + cpu.cpu; 128 129 err = bpf_map_update_elem(map_fd, &idx, &fd, 130 BPF_ANY); 131 if (err < 0) { 132 pr_err("Failed to update perf_event fd\n"); 133 goto out; 134 } 135 } 136 137 evsel->cgrp = leader_cgrp; 138 } 139 evsel->supported = true; 140 141 if (evsel->cgrp == cgrp) 142 continue; 143 144 cgrp = evsel->cgrp; 145 146 if (read_cgroup_id(cgrp) < 0) { 147 pr_err("Failed to get cgroup id\n"); 148 err = -1; 149 goto out; 150 } 151 152 map_fd = bpf_map__fd(skel->maps.cgrp_idx); 153 err = bpf_map_update_elem(map_fd, &cgrp->id, &i, BPF_ANY); 154 if (err < 0) { 155 pr_err("Failed to update cgroup index map\n"); 156 goto out; 157 } 158 159 i++; 160 } 161 162 /* 163 * bperf uses BPF_PROG_TEST_RUN to get accurate reading. Check 164 * whether the kernel support it 165 */ 166 prog_fd = bpf_program__fd(skel->progs.trigger_read); 167 err = bperf_trigger_reading(prog_fd, 0); 168 if (err) { 169 pr_warning("The kernel does not support test_run for raw_tp BPF programs.\n" 170 "Therefore, --for-each-cgroup might show inaccurate readings\n"); 171 err = 0; 172 } 173 174 out: 175 return err; 176 } 177 178 static int bperf_cgrp__load(struct evsel *evsel, 179 struct target *target __maybe_unused) 180 { 181 static bool bperf_loaded = false; 182 183 evsel->bperf_leader_prog_fd = -1; 184 evsel->bperf_leader_link_fd = -1; 185 186 if (!bperf_loaded && bperf_load_program(evsel->evlist)) 187 return -1; 188 189 bperf_loaded = true; 190 /* just to bypass bpf_counter_skip() */ 191 evsel->follower_skel = (struct bperf_follower_bpf *)skel; 192 193 return 0; 194 } 195 196 static int bperf_cgrp__install_pe(struct evsel *evsel __maybe_unused, 197 int cpu __maybe_unused, int fd __maybe_unused) 198 { 199 /* nothing to do */ 200 return 0; 201 } 202 203 /* 204 * trigger the leader prog on each cpu, so the cgrp_reading map could get 205 * the latest results. 206 */ 207 static int bperf_cgrp__sync_counters(struct evlist *evlist) 208 { 209 struct perf_cpu cpu; 210 int idx; 211 int prog_fd = bpf_program__fd(skel->progs.trigger_read); 212 213 perf_cpu_map__for_each_cpu(cpu, idx, evlist->core.all_cpus) 214 bperf_trigger_reading(prog_fd, cpu.cpu); 215 216 return 0; 217 } 218 219 static int bperf_cgrp__enable(struct evsel *evsel) 220 { 221 if (evsel->core.idx) 222 return 0; 223 224 bperf_cgrp__sync_counters(evsel->evlist); 225 226 skel->bss->enabled = 1; 227 return 0; 228 } 229 230 static int bperf_cgrp__disable(struct evsel *evsel) 231 { 232 if (evsel->core.idx) 233 return 0; 234 235 bperf_cgrp__sync_counters(evsel->evlist); 236 237 skel->bss->enabled = 0; 238 return 0; 239 } 240 241 static int bperf_cgrp__read(struct evsel *evsel) 242 { 243 struct evlist *evlist = evsel->evlist; 244 int total_cpus = cpu__max_cpu().cpu; 245 struct perf_counts_values *counts; 246 struct bpf_perf_event_value *values; 247 int reading_map_fd, err = 0; 248 249 if (evsel->core.idx) 250 return 0; 251 252 bperf_cgrp__sync_counters(evsel->evlist); 253 254 values = calloc(total_cpus, sizeof(*values)); 255 if (values == NULL) 256 return -ENOMEM; 257 258 reading_map_fd = bpf_map__fd(skel->maps.cgrp_readings); 259 260 evlist__for_each_entry(evlist, evsel) { 261 __u32 idx = evsel->core.idx; 262 int i; 263 struct perf_cpu cpu; 264 265 err = bpf_map_lookup_elem(reading_map_fd, &idx, values); 266 if (err) { 267 pr_err("bpf map lookup failed: idx=%u, event=%s, cgrp=%s\n", 268 idx, evsel__name(evsel), evsel->cgrp->name); 269 goto out; 270 } 271 272 perf_cpu_map__for_each_cpu(cpu, i, evsel->core.cpus) { 273 counts = perf_counts(evsel->counts, i, 0); 274 counts->val = values[cpu.cpu].counter; 275 counts->ena = values[cpu.cpu].enabled; 276 counts->run = values[cpu.cpu].running; 277 } 278 } 279 280 out: 281 free(values); 282 return err; 283 } 284 285 static int bperf_cgrp__destroy(struct evsel *evsel) 286 { 287 if (evsel->core.idx) 288 return 0; 289 290 bperf_cgroup_bpf__destroy(skel); 291 evsel__delete(cgrp_switch); // it'll destroy on_switch progs too 292 293 return 0; 294 } 295 296 struct bpf_counter_ops bperf_cgrp_ops = { 297 .load = bperf_cgrp__load, 298 .enable = bperf_cgrp__enable, 299 .disable = bperf_cgrp__disable, 300 .read = bperf_cgrp__read, 301 .install_pe = bperf_cgrp__install_pe, 302 .destroy = bperf_cgrp__destroy, 303 }; 304