tools/perf/util/record.c

   1 #include "evlist.h"
   2 #include "evsel.h"
   3 #include "cpumap.h"
   4 #include "parse-events.h"
   5
   6 typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
   7
   8 static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
   9 {
  10         struct perf_evlist *evlist;
  11         struct perf_evsel *evsel;
  12         int err = -EAGAIN, fd;
  13
  14         evlist = perf_evlist__new();
  15         if (!evlist)
  16                 return -ENOMEM;
  17
  18         if (parse_events(evlist, str))
  19                 goto out_delete;
  20
  21         evsel = perf_evlist__first(evlist);
  22
  23         fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
  24         if (fd < 0)
  25                 goto out_delete;
  26         close(fd);
  27
  28         fn(evsel);
  29
  30         fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
  31         if (fd < 0) {
  32                 if (errno == EINVAL)
  33                         err = -EINVAL;
  34                 goto out_delete;
  35         }
  36         close(fd);
  37         err = 0;
  38
  39 out_delete:
  40         perf_evlist__delete(evlist);
  41         return err;
  42 }
  43
  44 static bool perf_probe_api(setup_probe_fn_t fn)
  45 {
  46         const char *try[] = {"cycles:u", "instructions:u", "cpu-clock", NULL};
  47         struct cpu_map *cpus;
  48         int cpu, ret, i = 0;
  49
  50         cpus = cpu_map__new(NULL);
  51         if (!cpus)
  52                 return false;
  53         cpu = cpus->map[0];
  54         cpu_map__delete(cpus);
  55
  56         do {
  57                 ret = perf_do_probe_api(fn, cpu, try[i++]);
  58                 if (!ret)
  59                         return true;
  60         } while (ret == -EAGAIN && try[i]);
  61
  62         return false;
  63 }
  64
  65 static void perf_probe_sample_identifier(struct perf_evsel *evsel)
  66 {
  67         evsel->attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
  68 }
  69
  70 bool perf_can_sample_identifier(void)
  71 {
  72         return perf_probe_api(perf_probe_sample_identifier);
  73 }
  74
  75 void perf_evlist__config(struct perf_evlist *evlist,
  76                         struct perf_record_opts *opts)
  77 {
  78         struct perf_evsel *evsel;
  79         bool use_sample_identifier = false;
  80
  81         /*
  82          * Set the evsel leader links before we configure attributes,
  83          * since some might depend on this info.
  84          */
  85         if (opts->group)
  86                 perf_evlist__set_leader(evlist);
  87
  88         if (evlist->cpus->map[0] < 0)
  89                 opts->no_inherit = true;
  90
  91         list_for_each_entry(evsel, &evlist->entries, node)
  92                 perf_evsel__config(evsel, opts);
  93
  94         if (evlist->nr_entries > 1) {
  95                 struct perf_evsel *first = perf_evlist__first(evlist);
  96
  97                 list_for_each_entry(evsel, &evlist->entries, node) {
  98                         if (evsel->attr.sample_type == first->attr.sample_type)
  99                                 continue;
 100                         use_sample_identifier = perf_can_sample_identifier();
 101                         break;
 102                 }
 103                 list_for_each_entry(evsel, &evlist->entries, node)
 104                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
 105         }
 106
 107         perf_evlist__set_id_pos(evlist);
 108 }