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
  18         evlist = perf_evlist__new();
  19         if (!evlist)
  20                 return -ENOMEM;
  21
  22         if (parse_events(evlist, str))
  23                 goto out_delete;
  24
  25         evsel = perf_evlist__first(evlist);
  26
  27         fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, flags);
  28         if (fd < 0)
  29                 goto out_delete;
  30         close(fd);
  31
  32         fn(evsel);
  33
  34         fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1, flags);
  35         if (fd < 0) {
  36                 if (errno == EINVAL)
  37                         err = -EINVAL;
  38                 goto out_delete;
  39         }
  40         close(fd);
  41         err = 0;
  42
  43 out_delete:
  44         perf_evlist__delete(evlist);
  45         return err;
  46 }
  47
  48 static bool perf_probe_api(setup_probe_fn_t fn)
  49 {
  50         const char *try[] = {"cycles:u", "instructions:u", "cpu-clock", NULL};
  51         struct cpu_map *cpus;
  52         int cpu, ret, i = 0;
  53
  54         cpus = cpu_map__new(NULL);
  55         if (!cpus)
  56                 return false;
  57         cpu = cpus->map[0];
  58         cpu_map__delete(cpus);
  59
  60         do {
  61                 ret = perf_do_probe_api(fn, cpu, try[i++]);
  62                 if (!ret)
  63                         return true;
  64         } while (ret == -EAGAIN && try[i]);
  65
  66         return false;
  67 }
  68
  69 static void perf_probe_sample_identifier(struct perf_evsel *evsel)
  70 {
  71         evsel->attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
  72 }
  73
  74 static void perf_probe_comm_exec(struct perf_evsel *evsel)
  75 {
  76         evsel->attr.comm_exec = 1;
  77 }
  78
  79 bool perf_can_sample_identifier(void)
  80 {
  81         return perf_probe_api(perf_probe_sample_identifier);
  82 }
  83
  84 static bool perf_can_comm_exec(void)
  85 {
  86         return perf_probe_api(perf_probe_comm_exec);
  87 }
  88
  89 void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts)
  90 {
  91         struct perf_evsel *evsel;
  92         bool use_sample_identifier = false;
  93         bool use_comm_exec;
  94
  95         /*
  96          * Set the evsel leader links before we configure attributes,
  97          * since some might depend on this info.
  98          */
  99         if (opts->group)
 100                 perf_evlist__set_leader(evlist);
 101
 102         if (evlist->cpus->map[0] < 0)
 103                 opts->no_inherit = true;
 104
 105         use_comm_exec = perf_can_comm_exec();
 106
 107         evlist__for_each(evlist, evsel) {
 108                 perf_evsel__config(evsel, opts);
 109                 if (!evsel->idx && use_comm_exec)
 110                         evsel->attr.comm_exec = 1;
 111         }
 112
 113         if (evlist->nr_entries > 1) {
 114                 struct perf_evsel *first = perf_evlist__first(evlist);
 115
 116                 evlist__for_each(evlist, evsel) {
 117                         if (evsel->attr.sample_type == first->attr.sample_type)
 118                                 continue;
 119                         use_sample_identifier = perf_can_sample_identifier();
 120                         break;
 121                 }
 122                 evlist__for_each(evlist, evsel)
 123                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
 124         }
 125
 126         perf_evlist__set_id_pos(evlist);
 127 }
 128
 129 static int get_max_rate(unsigned int *rate)
 130 {
 131         char path[PATH_MAX];
 132         const char *procfs = procfs__mountpoint();
 133
 134         if (!procfs)
 135                 return -1;
 136
 137         snprintf(path, PATH_MAX,
 138                  "%s/sys/kernel/perf_event_max_sample_rate", procfs);
 139
 140         return filename__read_int(path, (int *) rate);
 141 }
 142
 143 static int record_opts__config_freq(struct record_opts *opts)
 144 {
 145         bool user_freq = opts->user_freq != UINT_MAX;
 146         unsigned int max_rate;
 147
 148         if (opts->user_interval != ULLONG_MAX)
 149                 opts->default_interval = opts->user_interval;
 150         if (user_freq)
 151                 opts->freq = opts->user_freq;
 152
 153         /*
 154          * User specified count overrides default frequency.
 155          */
 156         if (opts->default_interval)
 157                 opts->freq = 0;
 158         else if (opts->freq) {
 159                 opts->default_interval = opts->freq;
 160         } else {
 161                 pr_err("frequency and count are zero, aborting\n");
 162                 return -1;
 163         }
 164
 165         if (get_max_rate(&max_rate))
 166                 return 0;
 167
 168         /*
 169          * User specified frequency is over current maximum.
 170          */
 171         if (user_freq && (max_rate < opts->freq)) {
 172                 pr_err("Maximum frequency rate (%u) reached.\n"
 173                    "Please use -F freq option with lower value or consider\n"
 174                    "tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
 175                    max_rate);
 176                 return -1;
 177         }
 178
 179         /*
 180          * Default frequency is over current maximum.
 181          */
 182         if (max_rate < opts->freq) {
 183                 pr_warning("Lowering default frequency rate to %u.\n"
 184                            "Please consider tweaking "
 185                            "/proc/sys/kernel/perf_event_max_sample_rate.\n",
 186                            max_rate);
 187                 opts->freq = max_rate;
 188         }
 189
 190         return 0;
 191 }
 192
 193 int record_opts__config(struct record_opts *opts)
 194 {
 195         return record_opts__config_freq(opts);
 196 }
 197
 198 bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
 199 {
 200         struct perf_evlist *temp_evlist;
 201         struct perf_evsel *evsel;
 202         int err, fd, cpu;
 203         bool ret = false;
 204
 205         temp_evlist = perf_evlist__new();
 206         if (!temp_evlist)
 207                 return false;
 208
 209         err = parse_events(temp_evlist, str);
 210         if (err)
 211                 goto out_delete;
 212
 213         evsel = perf_evlist__last(temp_evlist);
 214
 215         if (!evlist || cpu_map__empty(evlist->cpus)) {
 216                 struct cpu_map *cpus = cpu_map__new(NULL);
 217
 218                 cpu =  cpus ? cpus->map[0] : 0;
 219                 cpu_map__delete(cpus);
 220         } else {
 221                 cpu = evlist->cpus->map[0];
 222         }
 223
 224         fd = sys_perf_event_open(&evsel->attr, -1, cpu, -1,
 225                                  perf_event_open_cloexec_flag());
 226         if (fd >= 0) {
 227                 close(fd);
 228                 ret = true;
 229         }
 230
 231 out_delete:
 232         perf_evlist__delete(temp_evlist);
 233         return ret;
 234 }