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 if (perf_cpu_map__cpu(evlist->core.user_requested_cpus, 0).cpu < 0) 103 opts->no_inherit = true; 104 105 use_comm_exec = perf_can_comm_exec(); 106 107 evlist__for_each_entry(evlist, evsel) { 108 evsel__config(evsel, opts, callchain); 109 if (evsel->tracking && use_comm_exec) 110 evsel->core.attr.comm_exec = 1; 111 } 112 113 /* Configure leader sampling here now that the sample type is known */ 114 evlist__for_each_entry(evlist, evsel) 115 evsel__config_leader_sampling(evsel, evlist); 116 117 if (opts->full_auxtrace || opts->sample_identifier) { 118 /* 119 * Need to be able to synthesize and parse selected events with 120 * arbitrary sample types, which requires always being able to 121 * match the id. 122 */ 123 use_sample_identifier = perf_can_sample_identifier(); 124 sample_id = true; 125 } else if (evlist->core.nr_entries > 1) { 126 struct evsel *first = evlist__first(evlist); 127 128 evlist__for_each_entry(evlist, evsel) { 129 if (evsel->core.attr.sample_type == first->core.attr.sample_type) 130 continue; 131 use_sample_identifier = perf_can_sample_identifier(); 132 break; 133 } 134 sample_id = true; 135 } 136 137 if (sample_id) { 138 evlist__for_each_entry(evlist, evsel) 139 evsel__set_sample_id(evsel, use_sample_identifier); 140 } 141 142 evlist__set_id_pos(evlist); 143 } 144 145 static int get_max_rate(unsigned int *rate) 146 { 147 return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate); 148 } 149 150 static int record_opts__config_freq(struct record_opts *opts) 151 { 152 bool user_freq = opts->user_freq != UINT_MAX; 153 bool user_interval = opts->user_interval != ULLONG_MAX; 154 unsigned int max_rate; 155 156 if (user_interval && user_freq) { 157 pr_err("cannot set frequency and period at the same time\n"); 158 return -1; 159 } 160 161 if (user_interval) 162 opts->default_interval = opts->user_interval; 163 if (user_freq) 164 opts->freq = opts->user_freq; 165 166 /* 167 * User specified count overrides default frequency. 168 */ 169 if (opts->default_interval) 170 opts->freq = 0; 171 else if (opts->freq) { 172 opts->default_interval = opts->freq; 173 } else { 174 pr_err("frequency and count are zero, aborting\n"); 175 return -1; 176 } 177 178 if (get_max_rate(&max_rate)) 179 return 0; 180 181 /* 182 * User specified frequency is over current maximum. 183 */ 184 if (user_freq && (max_rate < opts->freq)) { 185 if (opts->strict_freq) { 186 pr_err("error: Maximum frequency rate (%'u Hz) exceeded.\n" 187 " Please use -F freq option with a lower value or consider\n" 188 " tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n", 189 max_rate); 190 return -1; 191 } else { 192 pr_warning("warning: Maximum frequency rate (%'u Hz) exceeded, throttling from %'u Hz to %'u Hz.\n" 193 " The limit can be raised via /proc/sys/kernel/perf_event_max_sample_rate.\n" 194 " The kernel will lower it when perf's interrupts take too long.\n" 195 " Use --strict-freq to disable this throttling, refusing to record.\n", 196 max_rate, opts->freq, max_rate); 197 198 opts->freq = max_rate; 199 } 200 } 201 202 /* 203 * Default frequency is over current maximum. 204 */ 205 if (max_rate < opts->freq) { 206 pr_warning("Lowering default frequency rate from %u to %u.\n" 207 "Please consider tweaking " 208 "/proc/sys/kernel/perf_event_max_sample_rate.\n", 209 opts->freq, max_rate); 210 opts->freq = max_rate; 211 } 212 213 return 0; 214 } 215 216 int record_opts__config(struct record_opts *opts) 217 { 218 return record_opts__config_freq(opts); 219 } 220 221 bool evlist__can_select_event(struct evlist *evlist, const char *str) 222 { 223 struct evlist *temp_evlist; 224 struct evsel *evsel; 225 int err, fd; 226 struct perf_cpu cpu = { .cpu = 0 }; 227 bool ret = false; 228 pid_t pid = -1; 229 230 temp_evlist = evlist__new(); 231 if (!temp_evlist) 232 return false; 233 234 err = parse_event(temp_evlist, str); 235 if (err) 236 goto out_delete; 237 238 evsel = evlist__last(temp_evlist); 239 240 if (!evlist || perf_cpu_map__is_any_cpu_or_is_empty(evlist->core.user_requested_cpus)) { 241 struct perf_cpu_map *cpus = perf_cpu_map__new_online_cpus(); 242 243 if (cpus) 244 cpu = perf_cpu_map__cpu(cpus, 0); 245 246 perf_cpu_map__put(cpus); 247 } else { 248 cpu = perf_cpu_map__cpu(evlist->core.user_requested_cpus, 0); 249 } 250 251 while (1) { 252 fd = sys_perf_event_open(&evsel->core.attr, pid, cpu.cpu, -1, 253 perf_event_open_cloexec_flag()); 254 if (fd < 0) { 255 if (pid == -1 && errno == EACCES) { 256 pid = 0; 257 continue; 258 } 259 goto out_delete; 260 } 261 break; 262 } 263 close(fd); 264 ret = true; 265 266 out_delete: 267 evlist__delete(temp_evlist); 268 return ret; 269 } 270 271 int record__parse_freq(const struct option *opt, const char *str, int unset __maybe_unused) 272 { 273 unsigned int freq; 274 struct record_opts *opts = opt->value; 275 276 if (!str) 277 return -EINVAL; 278 279 if (strcasecmp(str, "max") == 0) { 280 if (get_max_rate(&freq)) { 281 pr_err("couldn't read /proc/sys/kernel/perf_event_max_sample_rate\n"); 282 return -1; 283 } 284 pr_info("info: Using a maximum frequency rate of %'d Hz\n", freq); 285 } else { 286 freq = atoi(str); 287 } 288 289 opts->user_freq = freq; 290 return 0; 291 } 292