tools/perf/util/record.c

   1 // SPDX-License-Identifier: GPL-2.0
   2 #include "evlist.h"
   3 #include "evsel.h"
   4 #include "cpumap.h"
   5 #include "parse-events.h"
   6 #include <errno.h>
   7 #include <api/fs/fs.h>
   8 #include "util.h"
   9 #include "cloexec.h"
  10
  11 typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
  12
  13 static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
  14 {
  15         struct perf_evlist *evlist;
  16         struct perf_evsel *evsel;
  17         unsigned long flags = perf_event_open_cloexec_flag();
  18         int err = -EAGAIN, fd;
  19         static pid_t pid = -1;
  20
  21         evlist = perf_evlist__new();
  22         if (!evlist)
  23                 return -ENOMEM;
  24
  25         if (parse_events(evlist, str, NULL))
  26                 goto out_delete;
  27
  28         evsel = perf_evlist__first(evlist);
  29
  30         while (1) {
  31                 fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1, flags);
  32                 if (fd < 0) {
  33                         if (pid == -1 && errno == EACCES) {
  34                                 pid = 0;
  35                                 continue;
  36                         }
  37                         goto out_delete;
  38                 }
  39                 break;
  40         }
  41         close(fd);
  42
  43         fn(evsel);
  44
  45         fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1, flags);
  46         if (fd < 0) {
  47                 if (errno == EINVAL)
  48                         err = -EINVAL;
  49                 goto out_delete;
  50         }
  51         close(fd);
  52         err = 0;
  53
  54 out_delete:
  55         perf_evlist__delete(evlist);
  56         return err;
  57 }
  58
  59 static bool perf_probe_api(setup_probe_fn_t fn)
  60 {
  61         const char *try[] = {"cycles:u", "instructions:u", "cpu-clock:u", NULL};
  62         struct cpu_map *cpus;
  63         int cpu, ret, i = 0;
  64
  65         cpus = cpu_map__new(NULL);
  66         if (!cpus)
  67                 return false;
  68         cpu = cpus->map[0];
  69         cpu_map__put(cpus);
  70
  71         do {
  72                 ret = perf_do_probe_api(fn, cpu, try[i++]);
  73                 if (!ret)
  74                         return true;
  75         } while (ret == -EAGAIN && try[i]);
  76
  77         return false;
  78 }
  79
  80 static void perf_probe_sample_identifier(struct perf_evsel *evsel)
  81 {
  82         evsel->attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
  83 }
  84
  85 static void perf_probe_comm_exec(struct perf_evsel *evsel)
  86 {
  87         evsel->attr.comm_exec = 1;
  88 }
  89
  90 static void perf_probe_context_switch(struct perf_evsel *evsel)
  91 {
  92         evsel->attr.context_switch = 1;
  93 }
  94
  95 bool perf_can_sample_identifier(void)
  96 {
  97         return perf_probe_api(perf_probe_sample_identifier);
  98 }
  99
 100 static bool perf_can_comm_exec(void)
 101 {
 102         return perf_probe_api(perf_probe_comm_exec);
 103 }
 104
 105 bool perf_can_record_switch_events(void)
 106 {
 107         return perf_probe_api(perf_probe_context_switch);
 108 }
 109
 110 bool perf_can_record_cpu_wide(void)
 111 {
 112         struct perf_event_attr attr = {
 113                 .type = PERF_TYPE_SOFTWARE,
 114                 .config = PERF_COUNT_SW_CPU_CLOCK,
 115                 .exclude_kernel = 1,
 116         };
 117         struct cpu_map *cpus;
 118         int cpu, fd;
 119
 120         cpus = cpu_map__new(NULL);
 121         if (!cpus)
 122                 return false;
 123         cpu = cpus->map[0];
 124         cpu_map__put(cpus);
 125
 126         fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
 127         if (fd < 0)
 128                 return false;
 129         close(fd);
 130
 131         return true;
 132 }
 133
 134 void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts,
 135                          struct callchain_param *callchain)
 136 {
 137         struct perf_evsel *evsel;
 138         bool use_sample_identifier = false;
 139         bool use_comm_exec;
 140
 141         /*
 142          * Set the evsel leader links before we configure attributes,
 143          * since some might depend on this info.
 144          */
 145         if (opts->group)
 146                 perf_evlist__set_leader(evlist);
 147
 148         if (evlist->cpus->map[0] < 0)
 149                 opts->no_inherit = true;
 150
 151         use_comm_exec = perf_can_comm_exec();
 152
 153         evlist__for_each_entry(evlist, evsel) {
 154                 perf_evsel__config(evsel, opts, callchain);
 155                 if (evsel->tracking && use_comm_exec)
 156                         evsel->attr.comm_exec = 1;
 157         }
 158
 159         if (opts->full_auxtrace) {
 160                 /*
 161                  * Need to be able to synthesize and parse selected events with
 162                  * arbitrary sample types, which requires always being able to
 163                  * match the id.
 164                  */
 165                 use_sample_identifier = perf_can_sample_identifier();
 166                 evlist__for_each_entry(evlist, evsel)
 167                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
 168         } else if (evlist->nr_entries > 1) {
 169                 struct perf_evsel *first = perf_evlist__first(evlist);
 170
 171                 evlist__for_each_entry(evlist, evsel) {
 172                         if (evsel->attr.sample_type == first->attr.sample_type)
 173                                 continue;
 174                         use_sample_identifier = perf_can_sample_identifier();
 175                         break;
 176                 }
 177                 evlist__for_each_entry(evlist, evsel)
 178                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
 179         }
 180
 181         perf_evlist__set_id_pos(evlist);
 182 }
 183
 184 static int get_max_rate(unsigned int *rate)
 185 {
 186         return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate);
 187 }
 188
 189 static int record_opts__config_freq(struct record_opts *opts)
 190 {
 191         bool user_freq = opts->user_freq != UINT_MAX;
 192         unsigned int max_rate;
 193
 194         if (opts->user_interval != ULLONG_MAX)
 195                 opts->default_interval = opts->user_interval;
 196         if (user_freq)
 197                 opts->freq = opts->user_freq;
 198
 199         /*
 200          * User specified count overrides default frequency.
 201          */
 202         if (opts->default_interval)
 203                 opts->freq = 0;
 204         else if (opts->freq) {
 205                 opts->default_interval = opts->freq;
 206         } else {
 207                 pr_err("frequency and count are zero, aborting\n");
 208                 return -1;
 209         }
 210
 211         if (get_max_rate(&max_rate))
 212                 return 0;
 213
 214         /*
 215          * User specified frequency is over current maximum.
 216          */
 217         if (user_freq && (max_rate < opts->freq)) {
 218                 pr_err("Maximum frequency rate (%u) reached.\n"
 219                    "Please use -F freq option with lower value or consider\n"
 220                    "tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
 221                    max_rate);
 222                 return -1;
 223         }
 224
 225         /*
 226          * Default frequency is over current maximum.
 227          */
 228         if (max_rate < opts->freq) {
 229                 pr_warning("Lowering default frequency rate to %u.\n"
 230                            "Please consider tweaking "
 231                            "/proc/sys/kernel/perf_event_max_sample_rate.\n",
 232                            max_rate);
 233                 opts->freq = max_rate;
 234         }
 235
 236         return 0;
 237 }
 238
 239 int record_opts__config(struct record_opts *opts)
 240 {
 241         return record_opts__config_freq(opts);
 242 }
 243
 244 bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
 245 {
 246         struct perf_evlist *temp_evlist;
 247         struct perf_evsel *evsel;
 248         int err, fd, cpu;
 249         bool ret = false;
 250         pid_t pid = -1;
 251
 252         temp_evlist = perf_evlist__new();
 253         if (!temp_evlist)
 254                 return false;
 255
 256         err = parse_events(temp_evlist, str, NULL);
 257         if (err)
 258                 goto out_delete;
 259
 260         evsel = perf_evlist__last(temp_evlist);
 261
 262         if (!evlist || cpu_map__empty(evlist->cpus)) {
 263                 struct cpu_map *cpus = cpu_map__new(NULL);
 264
 265                 cpu =  cpus ? cpus->map[0] : 0;
 266                 cpu_map__put(cpus);
 267         } else {
 268                 cpu = evlist->cpus->map[0];
 269         }
 270
 271         while (1) {
 272                 fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1,
 273                                          perf_event_open_cloexec_flag());
 274                 if (fd < 0) {
 275                         if (pid == -1 && errno == EACCES) {
 276                                 pid = 0;
 277                                 continue;
 278                         }
 279                         goto out_delete;
 280                 }
 281                 break;
 282         }
 283         close(fd);
 284         ret = true;
 285
 286 out_delete:
 287         perf_evlist__delete(temp_evlist);
 288         return ret;
 289 }