1 // SPDX-License-Identifier: GPL-2.0 2 #include "debug.h" 3 #include "evlist.h" 4 #include "evsel.h" 5 #include "evsel_config.h" 6 #include "parse-events.h" 7 #include <errno.h> 8 #include <limits.h> 9 #include <stdlib.h> 10 #include <api/fs/fs.h> 11 #include <subcmd/parse-options.h> 12 #include <perf/cpumap.h> 13 #include "cloexec.h" 14 #include "util/perf_api_probe.h" 15 #include "record.h" 16 #include "../perf-sys.h" 17 #include "topdown.h" 18 #include "map_symbol.h" 19 #include "mem-events.h" 20 21 /* 22 * evsel__config_leader_sampling() uses special rules for leader sampling. 23 * However, if the leader is an AUX area event, then assume the event to sample 24 * is the next event. 25 */ 26 static struct evsel *evsel__read_sampler(struct evsel *evsel, struct evlist *evlist) 27 { 28 struct evsel *leader = evsel__leader(evsel); 29 30 if (evsel__is_aux_event(leader) || arch_topdown_sample_read(leader) || 31 is_mem_loads_aux_event(leader)) { 32 evlist__for_each_entry(evlist, evsel) { 33 if (evsel__leader(evsel) == leader && evsel != evsel__leader(evsel)) 34 return evsel; 35 } 36 } 37 38 return leader; 39 } 40 41 static u64 evsel__config_term_mask(struct evsel *evsel) 42 { 43 struct evsel_config_term *term; 44 struct list_head *config_terms = &evsel->config_terms; 45 u64 term_types = 0; 46 47 list_for_each_entry(term, config_terms, list) { 48 term_types |= 1 << term->type; 49 } 50 return term_types; 51 } 52 53 static void evsel__config_leader_sampling(struct evsel *evsel, struct evlist *evlist) 54 { 55 struct perf_event_attr *attr = &evsel->core.attr; 56 struct evsel *leader = evsel__leader(evsel); 57 struct evsel *read_sampler; 58 u64 term_types, freq_mask; 59 60 if (!leader->sample_read) 61 return; 62 63 read_sampler = evsel__read_sampler(evsel, evlist); 64 65 if (evsel == read_sampler) 66 return; 67 68 term_types = evsel__config_term_mask(evsel); 69 /* 70 * Disable sampling for all group members except those with explicit 71 * config terms or the leader. In the case of an AUX area event, the 2nd 72 * event in the group is the one that 'leads' the sampling. 73 */ 74 freq_mask = (1 << EVSEL__CONFIG_TERM_FREQ) | (1 << EVSEL__CONFIG_TERM_PERIOD); 75 if ((term_types & freq_mask) == 0) { 76 attr->freq = 0; 77 attr->sample_freq = 0; 78 attr->sample_period = 0; 79 } 80 if ((term_types & (1 << EVSEL__CONFIG_TERM_OVERWRITE)) == 0) 81 attr->write_backward = 0; 82 83 /* 84 * We don't get a sample for slave events, we make them when delivering 85 * the group leader sample. Set the slave event to follow the master 86 * sample_type to ease up reporting. 87 * An AUX area event also has sample_type requirements, so also include 88 * the sample type bits from the leader's sample_type to cover that 89 * case. 90 */ 91 attr->sample_type = read_sampler->core.attr.sample_type | 92 leader->core.attr.sample_type; 93 } 94 95 void evlist__config(struct evlist *evlist, struct record_opts *opts, struct callchain_param *callchain) 96 { 97 struct evsel *evsel; 98 bool use_sample_identifier = false; 99 bool use_comm_exec; 100 bool sample_id = opts->sample_id; 101 102 /* 103 * Set the evsel leader links before we configure attributes, 104 * since some might depend on this info. 105 */ 106 if (opts->group) 107 evlist__set_leader(evlist); 108 109 if (perf_cpu_map__cpu(evlist->core.user_requested_cpus, 0).cpu < 0) 110 opts->no_inherit = true; 111 112 use_comm_exec = perf_can_comm_exec(); 113 114 evlist__for_each_entry(evlist, evsel) { 115 evsel__config(evsel, opts, callchain); 116 if (evsel->tracking && use_comm_exec) 117 evsel->core.attr.comm_exec = 1; 118 } 119 120 /* Configure leader sampling here now that the sample type is known */ 121 evlist__for_each_entry(evlist, evsel) 122 evsel__config_leader_sampling(evsel, evlist); 123 124 if (opts->full_auxtrace) { 125 /* 126 * Need to be able to synthesize and parse selected events with 127 * arbitrary sample types, which requires always being able to 128 * match the id. 129 */ 130 use_sample_identifier = perf_can_sample_identifier(); 131 sample_id = true; 132 } else if (evlist->core.nr_entries > 1) { 133 struct evsel *first = evlist__first(evlist); 134 135 evlist__for_each_entry(evlist, evsel) { 136 if (evsel->core.attr.sample_type == first->core.attr.sample_type) 137 continue; 138 use_sample_identifier = perf_can_sample_identifier(); 139 break; 140 } 141 sample_id = true; 142 } 143 144 if (sample_id) { 145 evlist__for_each_entry(evlist, evsel) 146 evsel__set_sample_id(evsel, use_sample_identifier); 147 } 148 149 evlist__set_id_pos(evlist); 150 } 151 152 static int get_max_rate(unsigned int *rate) 153 { 154 return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate); 155 } 156 157 static int record_opts__config_freq(struct record_opts *opts) 158 { 159 bool user_freq = opts->user_freq != UINT_MAX; 160 bool user_interval = opts->user_interval != ULLONG_MAX; 161 unsigned int max_rate; 162 163 if (user_interval && user_freq) { 164 pr_err("cannot set frequency and period at the same time\n"); 165 return -1; 166 } 167 168 if (user_interval) 169 opts->default_interval = opts->user_interval; 170 if (user_freq) 171 opts->freq = opts->user_freq; 172 173 /* 174 * User specified count overrides default frequency. 175 */ 176 if (opts->default_interval) 177 opts->freq = 0; 178 else if (opts->freq) { 179 opts->default_interval = opts->freq; 180 } else { 181 pr_err("frequency and count are zero, aborting\n"); 182 return -1; 183 } 184 185 if (get_max_rate(&max_rate)) 186 return 0; 187 188 /* 189 * User specified frequency is over current maximum. 190 */ 191 if (user_freq && (max_rate < opts->freq)) { 192 if (opts->strict_freq) { 193 pr_err("error: Maximum frequency rate (%'u Hz) exceeded.\n" 194 " Please use -F freq option with a lower value or consider\n" 195 " tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n", 196 max_rate); 197 return -1; 198 } else { 199 pr_warning("warning: Maximum frequency rate (%'u Hz) exceeded, throttling from %'u Hz to %'u Hz.\n" 200 " The limit can be raised via /proc/sys/kernel/perf_event_max_sample_rate.\n" 201 " The kernel will lower it when perf's interrupts take too long.\n" 202 " Use --strict-freq to disable this throttling, refusing to record.\n", 203 max_rate, opts->freq, max_rate); 204 205 opts->freq = max_rate; 206 } 207 } 208 209 /* 210 * Default frequency is over current maximum. 211 */ 212 if (max_rate < opts->freq) { 213 pr_warning("Lowering default frequency rate from %u to %u.\n" 214 "Please consider tweaking " 215 "/proc/sys/kernel/perf_event_max_sample_rate.\n", 216 opts->freq, max_rate); 217 opts->freq = max_rate; 218 } 219 220 return 0; 221 } 222 223 int record_opts__config(struct record_opts *opts) 224 { 225 return record_opts__config_freq(opts); 226 } 227 228 bool evlist__can_select_event(struct evlist *evlist, const char *str) 229 { 230 struct evlist *temp_evlist; 231 struct evsel *evsel; 232 int err, fd; 233 struct perf_cpu cpu = { .cpu = 0 }; 234 bool ret = false; 235 pid_t pid = -1; 236 237 temp_evlist = evlist__new(); 238 if (!temp_evlist) 239 return false; 240 241 err = parse_events(temp_evlist, str, NULL); 242 if (err) 243 goto out_delete; 244 245 evsel = evlist__last(temp_evlist); 246 247 if (!evlist || perf_cpu_map__empty(evlist->core.user_requested_cpus)) { 248 struct perf_cpu_map *cpus = perf_cpu_map__new(NULL); 249 250 if (cpus) 251 cpu = perf_cpu_map__cpu(cpus, 0); 252 253 perf_cpu_map__put(cpus); 254 } else { 255 cpu = perf_cpu_map__cpu(evlist->core.user_requested_cpus, 0); 256 } 257 258 while (1) { 259 fd = sys_perf_event_open(&evsel->core.attr, pid, cpu.cpu, -1, 260 perf_event_open_cloexec_flag()); 261 if (fd < 0) { 262 if (pid == -1 && errno == EACCES) { 263 pid = 0; 264 continue; 265 } 266 goto out_delete; 267 } 268 break; 269 } 270 close(fd); 271 ret = true; 272 273 out_delete: 274 evlist__delete(temp_evlist); 275 return ret; 276 } 277 278 int record__parse_freq(const struct option *opt, const char *str, int unset __maybe_unused) 279 { 280 unsigned int freq; 281 struct record_opts *opts = opt->value; 282 283 if (!str) 284 return -EINVAL; 285 286 if (strcasecmp(str, "max") == 0) { 287 if (get_max_rate(&freq)) { 288 pr_err("couldn't read /proc/sys/kernel/perf_event_max_sample_rate\n"); 289 return -1; 290 } 291 pr_info("info: Using a maximum frequency rate of %'d Hz\n", freq); 292 } else { 293 freq = atoi(str); 294 } 295 296 opts->user_freq = freq; 297 return 0; 298 } 299