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 == 0) 120 evsel->supported = true; 121 122 map_fd = bpf_map__fd(skel->maps.events); 123 perf_cpu_map__for_each_cpu(cpu, j, evsel->core.cpus) { 124 int fd = FD(evsel, j); 125 __u32 idx = evsel->core.idx * total_cpus + cpu.cpu; 126 127 bpf_map_update_elem(map_fd, &idx, &fd, BPF_ANY); 128 } 129 130 evsel->cgrp = leader_cgrp; 131 } 132 133 if (evsel->cgrp == cgrp) 134 continue; 135 136 cgrp = evsel->cgrp; 137 138 if (read_cgroup_id(cgrp) < 0) { 139 pr_debug("Failed to get cgroup id for %s\n", cgrp->name); 140 cgrp->id = 0; 141 } 142 143 map_fd = bpf_map__fd(skel->maps.cgrp_idx); 144 err = bpf_map_update_elem(map_fd, &cgrp->id, &i, BPF_ANY); 145 if (err < 0) { 146 pr_err("Failed to update cgroup index map\n"); 147 goto out; 148 } 149 150 i++; 151 } 152 153 /* 154 * bperf uses BPF_PROG_TEST_RUN to get accurate reading. Check 155 * whether the kernel support it 156 */ 157 prog_fd = bpf_program__fd(skel->progs.trigger_read); 158 err = bperf_trigger_reading(prog_fd, 0); 159 if (err) { 160 pr_warning("The kernel does not support test_run for raw_tp BPF programs.\n" 161 "Therefore, --for-each-cgroup might show inaccurate readings\n"); 162 err = 0; 163 } 164 165 out: 166 return err; 167 } 168 169 static int bperf_cgrp__load(struct evsel *evsel, 170 struct target *target __maybe_unused) 171 { 172 static bool bperf_loaded = false; 173 174 evsel->bperf_leader_prog_fd = -1; 175 evsel->bperf_leader_link_fd = -1; 176 177 if (!bperf_loaded && bperf_load_program(evsel->evlist)) 178 return -1; 179 180 bperf_loaded = true; 181 /* just to bypass bpf_counter_skip() */ 182 evsel->follower_skel = (struct bperf_follower_bpf *)skel; 183 184 return 0; 185 } 186 187 static int bperf_cgrp__install_pe(struct evsel *evsel __maybe_unused, 188 int cpu __maybe_unused, int fd __maybe_unused) 189 { 190 /* nothing to do */ 191 return 0; 192 } 193 194 /* 195 * trigger the leader prog on each cpu, so the cgrp_reading map could get 196 * the latest results. 197 */ 198 static int bperf_cgrp__sync_counters(struct evlist *evlist) 199 { 200 struct perf_cpu cpu; 201 int idx; 202 int prog_fd = bpf_program__fd(skel->progs.trigger_read); 203 204 perf_cpu_map__for_each_cpu(cpu, idx, evlist->core.all_cpus) 205 bperf_trigger_reading(prog_fd, cpu.cpu); 206 207 return 0; 208 } 209 210 static int bperf_cgrp__enable(struct evsel *evsel) 211 { 212 if (evsel->core.idx) 213 return 0; 214 215 bperf_cgrp__sync_counters(evsel->evlist); 216 217 skel->bss->enabled = 1; 218 return 0; 219 } 220 221 static int bperf_cgrp__disable(struct evsel *evsel) 222 { 223 if (evsel->core.idx) 224 return 0; 225 226 bperf_cgrp__sync_counters(evsel->evlist); 227 228 skel->bss->enabled = 0; 229 return 0; 230 } 231 232 static int bperf_cgrp__read(struct evsel *evsel) 233 { 234 struct evlist *evlist = evsel->evlist; 235 int total_cpus = cpu__max_cpu().cpu; 236 struct perf_counts_values *counts; 237 struct bpf_perf_event_value *values; 238 int reading_map_fd, err = 0; 239 240 if (evsel->core.idx) 241 return 0; 242 243 bperf_cgrp__sync_counters(evsel->evlist); 244 245 values = calloc(total_cpus, sizeof(*values)); 246 if (values == NULL) 247 return -ENOMEM; 248 249 reading_map_fd = bpf_map__fd(skel->maps.cgrp_readings); 250 251 evlist__for_each_entry(evlist, evsel) { 252 __u32 idx = evsel->core.idx; 253 int i; 254 struct perf_cpu cpu; 255 256 err = bpf_map_lookup_elem(reading_map_fd, &idx, values); 257 if (err) { 258 pr_err("bpf map lookup failed: idx=%u, event=%s, cgrp=%s\n", 259 idx, evsel__name(evsel), evsel->cgrp->name); 260 goto out; 261 } 262 263 perf_cpu_map__for_each_cpu(cpu, i, evsel->core.cpus) { 264 counts = perf_counts(evsel->counts, i, 0); 265 counts->val = values[cpu.cpu].counter; 266 counts->ena = values[cpu.cpu].enabled; 267 counts->run = values[cpu.cpu].running; 268 } 269 } 270 271 out: 272 free(values); 273 return err; 274 } 275 276 static int bperf_cgrp__destroy(struct evsel *evsel) 277 { 278 if (evsel->core.idx) 279 return 0; 280 281 bperf_cgroup_bpf__destroy(skel); 282 evsel__delete(cgrp_switch); // it'll destroy on_switch progs too 283 284 return 0; 285 } 286 287 struct bpf_counter_ops bperf_cgrp_ops = { 288 .load = bperf_cgrp__load, 289 .enable = bperf_cgrp__enable, 290 .disable = bperf_cgrp__disable, 291 .read = bperf_cgrp__read, 292 .install_pe = bperf_cgrp__install_pe, 293 .destroy = bperf_cgrp__destroy, 294 }; 295