kernel/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 {
 134         struct perf_evsel *evsel;
 135         bool use_sample_identifier = false;
 136         bool use_comm_exec;
 137
 138         /*
 139          * Set the evsel leader links before we configure attributes,
 140          * since some might depend on this info.
 141          */
 142         if (opts->group)
 143                 perf_evlist__set_leader(evlist);
 144
 145         if (evlist->cpus->map[0] < 0)
 146                 opts->no_inherit = true;
 147
 148         use_comm_exec = perf_can_comm_exec();
 149
 150         evlist__for_each(evlist, evsel) {
 151                 perf_evsel__config(evsel, opts);
 152                 if (evsel->tracking && use_comm_exec)
 153                         evsel->attr.comm_exec = 1;
 154         }
 155
 156         if (opts->full_auxtrace) {
 157                 /*
 158                  * Need to be able to synthesize and parse selected events with
 159                  * arbitrary sample types, which requires always being able to
 160                  * match the id.
 161                  */
 162                 use_sample_identifier = perf_can_sample_identifier();
 163                 evlist__for_each(evlist, evsel)
 164                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
 165         } else if (evlist->nr_entries > 1) {
 166                 struct perf_evsel *first = perf_evlist__first(evlist);
 167
 168                 evlist__for_each(evlist, evsel) {
 169                         if (evsel->attr.sample_type == first->attr.sample_type)
 170                                 continue;
 171                         use_sample_identifier = perf_can_sample_identifier();
 172                         break;
 173                 }
 174                 evlist__for_each(evlist, evsel)
 175                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
 176         }
 177
 178         perf_evlist__set_id_pos(evlist);
 179 }
 180
 181 static int get_max_rate(unsigned int *rate)
 182 {
 183         return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate);
 184 }
 185
 186 static int record_opts__config_freq(struct record_opts *opts)
 187 {
 188         bool user_freq = opts->user_freq != UINT_MAX;
 189         unsigned int max_rate;
 190
 191         if (opts->user_interval != ULLONG_MAX)
 192                 opts->default_interval = opts->user_interval;
 193         if (user_freq)
 194                 opts->freq = opts->user_freq;
 195
 196         /*
 197          * User specified count overrides default frequency.
 198          */
 199         if (opts->default_interval)
 200                 opts->freq = 0;
 201         else if (opts->freq) {
 202                 opts->default_interval = opts->freq;
 203         } else {
 204                 pr_err("frequency and count are zero, aborting\n");
 205                 return -1;
 206         }
 207
 208         if (get_max_rate(&max_rate))
 209                 return 0;
 210
 211         /*
 212          * User specified frequency is over current maximum.
 213          */
 214         if (user_freq && (max_rate < opts->freq)) {
 215                 pr_err("Maximum frequency rate (%u) reached.\n"
 216                    "Please use -F freq option with lower value or consider\n"
 217                    "tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
 218                    max_rate);
 219                 return -1;
 220         }
 221
 222         /*
 223          * Default frequency is over current maximum.
 224          */
 225         if (max_rate < opts->freq) {
 226                 pr_warning("Lowering default frequency rate to %u.\n"
 227                            "Please consider tweaking "
 228                            "/proc/sys/kernel/perf_event_max_sample_rate.\n",
 229                            max_rate);
 230                 opts->freq = max_rate;
 231         }
 232
 233         return 0;
 234 }
 235
 236 int record_opts__config(struct record_opts *opts)
 237 {
 238         return record_opts__config_freq(opts);
 239 }
 240
 241 bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
 242 {
 243         struct perf_evlist *temp_evlist;
 244         struct perf_evsel *evsel;
 245         int err, fd, cpu;
 246         bool ret = false;
 247         pid_t pid = -1;
 248
 249         temp_evlist = perf_evlist__new();
 250         if (!temp_evlist)
 251                 return false;
 252
 253         err = parse_events(temp_evlist, str, NULL);
 254         if (err)
 255                 goto out_delete;
 256
 257         evsel = perf_evlist__last(temp_evlist);
 258
 259         if (!evlist || cpu_map__empty(evlist->cpus)) {
 260                 struct cpu_map *cpus = cpu_map__new(NULL);
 261
 262                 cpu =  cpus ? cpus->map[0] : 0;
 263                 cpu_map__put(cpus);
 264         } else {
 265                 cpu = evlist->cpus->map[0];
 266         }
 267
 268         while (1) {
 269                 fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1,
 270                                          perf_event_open_cloexec_flag());
 271                 if (fd < 0) {
 272                         if (pid == -1 && errno == EACCES) {
 273                                 pid = 0;
 274                                 continue;
 275                         }
 276                         goto out_delete;
 277                 }
 278                 break;
 279         }
 280         close(fd);
 281         ret = true;
 282
 283 out_delete:
 284         perf_evlist__delete(temp_evlist);
 285         return ret;
 286 }