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 __u32 i, cpu; 50 __u32 nr_cpus = evlist->core.all_cpus->nr; 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 for (i = 0; i < nr_cpus; i++) { 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, evlist->core.all_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 for (cpu = 0; cpu < nr_cpus; cpu++) { 126 int fd = FD(evsel, cpu); 127 __u32 idx = evsel->core.idx * total_cpus + 128 evlist->core.all_cpus->map[cpu].cpu; 129 130 err = bpf_map_update_elem(map_fd, &idx, &fd, 131 BPF_ANY); 132 if (err < 0) { 133 pr_err("Failed to update perf_event fd\n"); 134 goto out; 135 } 136 } 137 138 evsel->cgrp = leader_cgrp; 139 } 140 evsel->supported = true; 141 142 if (evsel->cgrp == cgrp) 143 continue; 144 145 cgrp = evsel->cgrp; 146 147 if (read_cgroup_id(cgrp) < 0) { 148 pr_err("Failed to get cgroup id\n"); 149 err = -1; 150 goto out; 151 } 152 153 map_fd = bpf_map__fd(skel->maps.cgrp_idx); 154 err = bpf_map_update_elem(map_fd, &cgrp->id, &i, BPF_ANY); 155 if (err < 0) { 156 pr_err("Failed to update cgroup index map\n"); 157 goto out; 158 } 159 160 i++; 161 } 162 163 /* 164 * bperf uses BPF_PROG_TEST_RUN to get accurate reading. Check 165 * whether the kernel support it 166 */ 167 prog_fd = bpf_program__fd(skel->progs.trigger_read); 168 err = bperf_trigger_reading(prog_fd, 0); 169 if (err) { 170 pr_warning("The kernel does not support test_run for raw_tp BPF programs.\n" 171 "Therefore, --for-each-cgroup might show inaccurate readings\n"); 172 err = 0; 173 } 174 175 out: 176 return err; 177 } 178 179 static int bperf_cgrp__load(struct evsel *evsel, 180 struct target *target __maybe_unused) 181 { 182 static bool bperf_loaded = false; 183 184 evsel->bperf_leader_prog_fd = -1; 185 evsel->bperf_leader_link_fd = -1; 186 187 if (!bperf_loaded && bperf_load_program(evsel->evlist)) 188 return -1; 189 190 bperf_loaded = true; 191 /* just to bypass bpf_counter_skip() */ 192 evsel->follower_skel = (struct bperf_follower_bpf *)skel; 193 194 return 0; 195 } 196 197 static int bperf_cgrp__install_pe(struct evsel *evsel __maybe_unused, 198 int cpu __maybe_unused, int fd __maybe_unused) 199 { 200 /* nothing to do */ 201 return 0; 202 } 203 204 /* 205 * trigger the leader prog on each cpu, so the cgrp_reading map could get 206 * the latest results. 207 */ 208 static int bperf_cgrp__sync_counters(struct evlist *evlist) 209 { 210 int i, cpu; 211 int nr_cpus = evlist->core.all_cpus->nr; 212 int prog_fd = bpf_program__fd(skel->progs.trigger_read); 213 214 for (i = 0; i < nr_cpus; i++) { 215 cpu = evlist->core.all_cpus->map[i].cpu; 216 bperf_trigger_reading(prog_fd, cpu); 217 } 218 219 return 0; 220 } 221 222 static int bperf_cgrp__enable(struct evsel *evsel) 223 { 224 if (evsel->core.idx) 225 return 0; 226 227 bperf_cgrp__sync_counters(evsel->evlist); 228 229 skel->bss->enabled = 1; 230 return 0; 231 } 232 233 static int bperf_cgrp__disable(struct evsel *evsel) 234 { 235 if (evsel->core.idx) 236 return 0; 237 238 bperf_cgrp__sync_counters(evsel->evlist); 239 240 skel->bss->enabled = 0; 241 return 0; 242 } 243 244 static int bperf_cgrp__read(struct evsel *evsel) 245 { 246 struct evlist *evlist = evsel->evlist; 247 int i, cpu, nr_cpus = evlist->core.all_cpus->nr; 248 int total_cpus = cpu__max_cpu().cpu; 249 struct perf_counts_values *counts; 250 struct bpf_perf_event_value *values; 251 int reading_map_fd, err = 0; 252 __u32 idx; 253 254 if (evsel->core.idx) 255 return 0; 256 257 bperf_cgrp__sync_counters(evsel->evlist); 258 259 values = calloc(total_cpus, sizeof(*values)); 260 if (values == NULL) 261 return -ENOMEM; 262 263 reading_map_fd = bpf_map__fd(skel->maps.cgrp_readings); 264 265 evlist__for_each_entry(evlist, evsel) { 266 idx = evsel->core.idx; 267 err = bpf_map_lookup_elem(reading_map_fd, &idx, values); 268 if (err) { 269 pr_err("bpf map lookup falied: idx=%u, event=%s, cgrp=%s\n", 270 idx, evsel__name(evsel), evsel->cgrp->name); 271 goto out; 272 } 273 274 for (i = 0; i < nr_cpus; i++) { 275 cpu = evlist->core.all_cpus->map[i].cpu; 276 277 counts = perf_counts(evsel->counts, i, 0); 278 counts->val = values[cpu].counter; 279 counts->ena = values[cpu].enabled; 280 counts->run = values[cpu].running; 281 } 282 } 283 284 out: 285 free(values); 286 return err; 287 } 288 289 static int bperf_cgrp__destroy(struct evsel *evsel) 290 { 291 if (evsel->core.idx) 292 return 0; 293 294 bperf_cgroup_bpf__destroy(skel); 295 evsel__delete(cgrp_switch); // it'll destroy on_switch progs too 296 297 return 0; 298 } 299 300 struct bpf_counter_ops bperf_cgrp_ops = { 301 .load = bperf_cgrp__load, 302 .enable = bperf_cgrp__enable, 303 .disable = bperf_cgrp__disable, 304 .read = bperf_cgrp__read, 305 .install_pe = bperf_cgrp__install_pe, 306 .destroy = bperf_cgrp__destroy, 307 }; 308