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 void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts)
 109 {
 110         struct perf_evsel *evsel;
 111         bool use_sample_identifier = false;
 112         bool use_comm_exec;
 113
 114         /*
 115          * Set the evsel leader links before we configure attributes,
 116          * since some might depend on this info.
 117          */
 118         if (opts->group)
 119                 perf_evlist__set_leader(evlist);
 120
 121         if (evlist->cpus->map[0] < 0)
 122                 opts->no_inherit = true;
 123
 124         use_comm_exec = perf_can_comm_exec();
 125
 126         evlist__for_each(evlist, evsel) {
 127                 perf_evsel__config(evsel, opts);
 128                 if (evsel->tracking && use_comm_exec)
 129                         evsel->attr.comm_exec = 1;
 130         }
 131
 132         if (opts->full_auxtrace) {
 133                 /*
 134                  * Need to be able to synthesize and parse selected events with
 135                  * arbitrary sample types, which requires always being able to
 136                  * match the id.
 137                  */
 138                 use_sample_identifier = perf_can_sample_identifier();
 139                 evlist__for_each(evlist, evsel)
 140                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
 141         } else if (evlist->nr_entries > 1) {
 142                 struct perf_evsel *first = perf_evlist__first(evlist);
 143
 144                 evlist__for_each(evlist, evsel) {
 145                         if (evsel->attr.sample_type == first->attr.sample_type)
 146                                 continue;
 147                         use_sample_identifier = perf_can_sample_identifier();
 148                         break;
 149                 }
 150                 evlist__for_each(evlist, evsel)
 151                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
 152         }
 153
 154         perf_evlist__set_id_pos(evlist);
 155 }
 156
 157 static int get_max_rate(unsigned int *rate)
 158 {
 159         return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate);
 160 }
 161
 162 static int record_opts__config_freq(struct record_opts *opts)
 163 {
 164         bool user_freq = opts->user_freq != UINT_MAX;
 165         unsigned int max_rate;
 166
 167         if (opts->user_interval != ULLONG_MAX)
 168                 opts->default_interval = opts->user_interval;
 169         if (user_freq)
 170                 opts->freq = opts->user_freq;
 171
 172         /*
 173          * User specified count overrides default frequency.
 174          */
 175         if (opts->default_interval)
 176                 opts->freq = 0;
 177         else if (opts->freq) {
 178                 opts->default_interval = opts->freq;
 179         } else {
 180                 pr_err("frequency and count are zero, aborting\n");
 181                 return -1;
 182         }
 183
 184         if (get_max_rate(&max_rate))
 185                 return 0;
 186
 187         /*
 188          * User specified frequency is over current maximum.
 189          */
 190         if (user_freq && (max_rate < opts->freq)) {
 191                 pr_err("Maximum frequency rate (%u) reached.\n"
 192                    "Please use -F freq option with lower value or consider\n"
 193                    "tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
 194                    max_rate);
 195                 return -1;
 196         }
 197
 198         /*
 199          * Default frequency is over current maximum.
 200          */
 201         if (max_rate < opts->freq) {
 202                 pr_warning("Lowering default frequency rate to %u.\n"
 203                            "Please consider tweaking "
 204                            "/proc/sys/kernel/perf_event_max_sample_rate.\n",
 205                            max_rate);
 206                 opts->freq = max_rate;
 207         }
 208
 209         return 0;
 210 }
 211
 212 int record_opts__config(struct record_opts *opts)
 213 {
 214         return record_opts__config_freq(opts);
 215 }
 216
 217 bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
 218 {
 219         struct perf_evlist *temp_evlist;
 220         struct perf_evsel *evsel;
 221         int err, fd, cpu;
 222         bool ret = false;
 223         pid_t pid = -1;
 224
 225         temp_evlist = perf_evlist__new();
 226         if (!temp_evlist)
 227                 return false;
 228
 229         err = parse_events(temp_evlist, str, NULL);
 230         if (err)
 231                 goto out_delete;
 232
 233         evsel = perf_evlist__last(temp_evlist);
 234
 235         if (!evlist || cpu_map__empty(evlist->cpus)) {
 236                 struct cpu_map *cpus = cpu_map__new(NULL);
 237
 238                 cpu =  cpus ? cpus->map[0] : 0;
 239                 cpu_map__put(cpus);
 240         } else {
 241                 cpu = evlist->cpus->map[0];
 242         }
 243
 244         while (1) {
 245                 fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1,
 246                                          perf_event_open_cloexec_flag());
 247                 if (fd < 0) {
 248                         if (pid == -1 && errno == EACCES) {
 249                                 pid = 0;
 250                                 continue;
 251                         }
 252                         goto out_delete;
 253                 }
 254                 break;
 255         }
 256         close(fd);
 257         ret = true;
 258
 259 out_delete:
 260         perf_evlist__delete(temp_evlist);
 261         return ret;
 262 }