tools/perf/util/record.c

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