tools/perf/util/record.c

   1 #include "evlist.h"
   2 #include "evsel.h"
   3 #include "cpumap.h"
   4 #include "parse-events.h"
   5 #include "fs.h"
   6 #include "util.h"
   7
   8 typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
   9
  10 static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
  11 {
  12         struct perf_evlist *evlist;
  13         struct perf_evsel *evsel;
  14         int err = -EAGAIN, fd;
  15
  16         evlist = perf_evlist__new();
  17         if (!evlist)
  18                 return -ENOMEM;
  19
  20         if (parse_events(evlist, str))
  21                 goto out_delete;
  22
  23         evsel = perf_evlist__first(evlist);
  24
  25         fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
  26         if (fd < 0)
  27                 goto out_delete;
  28         close(fd);
  29
  30         fn(evsel);
  31
  32         fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
  33         if (fd < 0) {
  34                 if (errno == EINVAL)
  35                         err = -EINVAL;
  36                 goto out_delete;
  37         }
  38         close(fd);
  39         err = 0;
  40
  41 out_delete:
  42         perf_evlist__delete(evlist);
  43         return err;
  44 }
  45
  46 static bool perf_probe_api(setup_probe_fn_t fn)
  47 {
  48         const char *try[] = {"cycles:u", "instructions:u", "cpu-clock", NULL};
  49         struct cpu_map *cpus;
  50         int cpu, ret, i = 0;
  51
  52         cpus = cpu_map__new(NULL);
  53         if (!cpus)
  54                 return false;
  55         cpu = cpus->map[0];
  56         cpu_map__delete(cpus);
  57
  58         do {
  59                 ret = perf_do_probe_api(fn, cpu, try[i++]);
  60                 if (!ret)
  61                         return true;
  62         } while (ret == -EAGAIN && try[i]);
  63
  64         return false;
  65 }
  66
  67 static void perf_probe_sample_identifier(struct perf_evsel *evsel)
  68 {
  69         evsel->attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
  70 }
  71
  72 bool perf_can_sample_identifier(void)
  73 {
  74         return perf_probe_api(perf_probe_sample_identifier);
  75 }
  76
  77 void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts)
  78 {
  79         struct perf_evsel *evsel;
  80         bool use_sample_identifier = false;
  81
  82         /*
  83          * Set the evsel leader links before we configure attributes,
  84          * since some might depend on this info.
  85          */
  86         if (opts->group)
  87                 perf_evlist__set_leader(evlist);
  88
  89         if (evlist->cpus->map[0] < 0)
  90                 opts->no_inherit = true;
  91
  92         evlist__for_each(evlist, evsel)
  93                 perf_evsel__config(evsel, opts);
  94
  95         if (evlist->nr_entries > 1) {
  96                 struct perf_evsel *first = perf_evlist__first(evlist);
  97
  98                 evlist__for_each(evlist, evsel) {
  99                         if (evsel->attr.sample_type == first->attr.sample_type)
 100                                 continue;
 101                         use_sample_identifier = perf_can_sample_identifier();
 102                         break;
 103                 }
 104                 evlist__for_each(evlist, evsel)
 105                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
 106         }
 107
 108         perf_evlist__set_id_pos(evlist);
 109 }
 110
 111 static int get_max_rate(unsigned int *rate)
 112 {
 113         char path[PATH_MAX];
 114         const char *procfs = procfs__mountpoint();
 115
 116         if (!procfs)
 117                 return -1;
 118
 119         snprintf(path, PATH_MAX,
 120                  "%s/sys/kernel/perf_event_max_sample_rate", procfs);
 121
 122         return filename__read_int(path, (int *) rate);
 123 }
 124
 125 static int record_opts__config_freq(struct record_opts *opts)
 126 {
 127         bool user_freq = opts->user_freq != UINT_MAX;
 128         unsigned int max_rate;
 129
 130         if (opts->user_interval != ULLONG_MAX)
 131                 opts->default_interval = opts->user_interval;
 132         if (user_freq)
 133                 opts->freq = opts->user_freq;
 134
 135         /*
 136          * User specified count overrides default frequency.
 137          */
 138         if (opts->default_interval)
 139                 opts->freq = 0;
 140         else if (opts->freq) {
 141                 opts->default_interval = opts->freq;
 142         } else {
 143                 pr_err("frequency and count are zero, aborting\n");
 144                 return -1;
 145         }
 146
 147         if (get_max_rate(&max_rate))
 148                 return 0;
 149
 150         /*
 151          * User specified frequency is over current maximum.
 152          */
 153         if (user_freq && (max_rate < opts->freq)) {
 154                 pr_err("Maximum frequency rate (%u) reached.\n"
 155                    "Please use -F freq option with lower value or consider\n"
 156                    "tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
 157                    max_rate);
 158                 return -1;
 159         }
 160
 161         /*
 162          * Default frequency is over current maximum.
 163          */
 164         if (max_rate < opts->freq) {
 165                 pr_warning("Lowering default frequency rate to %u.\n"
 166                            "Please consider tweaking "
 167                            "/proc/sys/kernel/perf_event_max_sample_rate.\n",
 168                            max_rate);
 169                 opts->freq = max_rate;
 170         }
 171
 172         return 0;
 173 }
 174
 175 int record_opts__config(struct record_opts *opts)
 176 {
 177         return record_opts__config_freq(opts);
 178 }
 179
 180 bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
 181 {
 182         struct perf_evlist *temp_evlist;
 183         struct perf_evsel *evsel;
 184         int err, fd, cpu;
 185         bool ret = false;
 186
 187         temp_evlist = perf_evlist__new();
 188         if (!temp_evlist)
 189                 return false;
 190
 191         err = parse_events(temp_evlist, str);
 192         if (err)
 193                 goto out_delete;
 194
 195         evsel = perf_evlist__last(temp_evlist);
 196
 197         if (!evlist || cpu_map__empty(evlist->cpus)) {
 198                 struct cpu_map *cpus = cpu_map__new(NULL);
 199
 200                 cpu =  cpus ? cpus->map[0] : 0;
 201                 cpu_map__delete(cpus);
 202         } else {
 203                 cpu = evlist->cpus->map[0];
 204         }
 205
 206         fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, 0);
 207         if (fd >= 0) {
 208                 close(fd);
 209                 ret = true;
 210         }
 211
 212 out_delete:
 213         perf_evlist__delete(temp_evlist);
 214         return ret;
 215 }