tools/perf/util/record.c

   1 #include "evlist.h"
   2 #include "evsel.h"
   3 #include "cpumap.h"
   4 #include "parse-events.h"
   5 #include <errno.h>
   6 #include <api/fs/fs.h>
   7 #include "util.h"
   8 #include "cloexec.h"
   9
  10 typedef void (*setup_probe_fn_t)(struct perf_evsel *evsel);
  11
  12 static int perf_do_probe_api(setup_probe_fn_t fn, int cpu, const char *str)
  13 {
  14         struct perf_evlist *evlist;
  15         struct perf_evsel *evsel;
  16         unsigned long flags = perf_event_open_cloexec_flag();
  17         int err = -EAGAIN, fd;
  18         static pid_t pid = -1;
  19
  20         evlist = perf_evlist__new();
  21         if (!evlist)
  22                 return -ENOMEM;
  23
  24         if (parse_events(evlist, str, NULL))
  25                 goto out_delete;
  26
  27         evsel = perf_evlist__first(evlist);
  28
  29         while (1) {
  30                 fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1, flags);
  31                 if (fd < 0) {
  32                         if (pid == -1 && errno == EACCES) {
  33                                 pid = 0;
  34                                 continue;
  35                         }
  36                         goto out_delete;
  37                 }
  38                 break;
  39         }
  40         close(fd);
  41
  42         fn(evsel);
  43
  44         fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1, flags);
  45         if (fd < 0) {
  46                 if (errno == EINVAL)
  47                         err = -EINVAL;
  48                 goto out_delete;
  49         }
  50         close(fd);
  51         err = 0;
  52
  53 out_delete:
  54         perf_evlist__delete(evlist);
  55         return err;
  56 }
  57
  58 static bool perf_probe_api(setup_probe_fn_t fn)
  59 {
  60         const char *try[] = {"cycles:u", "instructions:u", "cpu-clock:u", NULL};
  61         struct cpu_map *cpus;
  62         int cpu, ret, i = 0;
  63
  64         cpus = cpu_map__new(NULL);
  65         if (!cpus)
  66                 return false;
  67         cpu = cpus->map[0];
  68         cpu_map__put(cpus);
  69
  70         do {
  71                 ret = perf_do_probe_api(fn, cpu, try[i++]);
  72                 if (!ret)
  73                         return true;
  74         } while (ret == -EAGAIN && try[i]);
  75
  76         return false;
  77 }
  78
  79 static void perf_probe_sample_identifier(struct perf_evsel *evsel)
  80 {
  81         evsel->attr.sample_type |= PERF_SAMPLE_IDENTIFIER;
  82 }
  83
  84 static void perf_probe_comm_exec(struct perf_evsel *evsel)
  85 {
  86         evsel->attr.comm_exec = 1;
  87 }
  88
  89 static void perf_probe_context_switch(struct perf_evsel *evsel)
  90 {
  91         evsel->attr.context_switch = 1;
  92 }
  93
  94 bool perf_can_sample_identifier(void)
  95 {
  96         return perf_probe_api(perf_probe_sample_identifier);
  97 }
  98
  99 static bool perf_can_comm_exec(void)
 100 {
 101         return perf_probe_api(perf_probe_comm_exec);
 102 }
 103
 104 bool perf_can_record_switch_events(void)
 105 {
 106         return perf_probe_api(perf_probe_context_switch);
 107 }
 108
 109 bool perf_can_record_cpu_wide(void)
 110 {
 111         struct perf_event_attr attr = {
 112                 .type = PERF_TYPE_SOFTWARE,
 113                 .config = PERF_COUNT_SW_CPU_CLOCK,
 114                 .exclude_kernel = 1,
 115         };
 116         struct cpu_map *cpus;
 117         int cpu, fd;
 118
 119         cpus = cpu_map__new(NULL);
 120         if (!cpus)
 121                 return false;
 122         cpu = cpus->map[0];
 123         cpu_map__put(cpus);
 124
 125         fd = sys_perf_event_open(&attr, -1, cpu, -1, 0);
 126         if (fd < 0)
 127                 return false;
 128         close(fd);
 129
 130         return true;
 131 }
 132
 133 void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts,
 134                          struct callchain_param *callchain)
 135 {
 136         struct perf_evsel *evsel;
 137         bool use_sample_identifier = false;
 138         bool use_comm_exec;
 139
 140         /*
 141          * Set the evsel leader links before we configure attributes,
 142          * since some might depend on this info.
 143          */
 144         if (opts->group)
 145                 perf_evlist__set_leader(evlist);
 146
 147         if (evlist->cpus->map[0] < 0)
 148                 opts->no_inherit = true;
 149
 150         use_comm_exec = perf_can_comm_exec();
 151
 152         evlist__for_each_entry(evlist, evsel) {
 153                 perf_evsel__config(evsel, opts, callchain);
 154                 if (evsel->tracking && use_comm_exec)
 155                         evsel->attr.comm_exec = 1;
 156         }
 157
 158         if (opts->full_auxtrace) {
 159                 /*
 160                  * Need to be able to synthesize and parse selected events with
 161                  * arbitrary sample types, which requires always being able to
 162                  * match the id.
 163                  */
 164                 use_sample_identifier = perf_can_sample_identifier();
 165                 evlist__for_each_entry(evlist, evsel)
 166                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
 167         } else if (evlist->nr_entries > 1) {
 168                 struct perf_evsel *first = perf_evlist__first(evlist);
 169
 170                 evlist__for_each_entry(evlist, evsel) {
 171                         if (evsel->attr.sample_type == first->attr.sample_type)
 172                                 continue;
 173                         use_sample_identifier = perf_can_sample_identifier();
 174                         break;
 175                 }
 176                 evlist__for_each_entry(evlist, evsel)
 177                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
 178         }
 179
 180         perf_evlist__set_id_pos(evlist);
 181 }
 182
 183 static int get_max_rate(unsigned int *rate)
 184 {
 185         return sysctl__read_int("kernel/perf_event_max_sample_rate", (int *)rate);
 186 }
 187
 188 static int record_opts__config_freq(struct record_opts *opts)
 189 {
 190         bool user_freq = opts->user_freq != UINT_MAX;
 191         unsigned int max_rate;
 192
 193         if (opts->user_interval != ULLONG_MAX)
 194                 opts->default_interval = opts->user_interval;
 195         if (user_freq)
 196                 opts->freq = opts->user_freq;
 197
 198         /*
 199          * User specified count overrides default frequency.
 200          */
 201         if (opts->default_interval)
 202                 opts->freq = 0;
 203         else if (opts->freq) {
 204                 opts->default_interval = opts->freq;
 205         } else {
 206                 pr_err("frequency and count are zero, aborting\n");
 207                 return -1;
 208         }
 209
 210         if (get_max_rate(&max_rate))
 211                 return 0;
 212
 213         /*
 214          * User specified frequency is over current maximum.
 215          */
 216         if (user_freq && (max_rate < opts->freq)) {
 217                 pr_err("Maximum frequency rate (%u) reached.\n"
 218                    "Please use -F freq option with lower value or consider\n"
 219                    "tweaking /proc/sys/kernel/perf_event_max_sample_rate.\n",
 220                    max_rate);
 221                 return -1;
 222         }
 223
 224         /*
 225          * Default frequency is over current maximum.
 226          */
 227         if (max_rate < opts->freq) {
 228                 pr_warning("Lowering default frequency rate to %u.\n"
 229                            "Please consider tweaking "
 230                            "/proc/sys/kernel/perf_event_max_sample_rate.\n",
 231                            max_rate);
 232                 opts->freq = max_rate;
 233         }
 234
 235         return 0;
 236 }
 237
 238 int record_opts__config(struct record_opts *opts)
 239 {
 240         return record_opts__config_freq(opts);
 241 }
 242
 243 bool perf_evlist__can_select_event(struct perf_evlist *evlist, const char *str)
 244 {
 245         struct perf_evlist *temp_evlist;
 246         struct perf_evsel *evsel;
 247         int err, fd, cpu;
 248         bool ret = false;
 249         pid_t pid = -1;
 250
 251         temp_evlist = perf_evlist__new();
 252         if (!temp_evlist)
 253                 return false;
 254
 255         err = parse_events(temp_evlist, str, NULL);
 256         if (err)
 257                 goto out_delete;
 258
 259         evsel = perf_evlist__last(temp_evlist);
 260
 261         if (!evlist || cpu_map__empty(evlist->cpus)) {
 262                 struct cpu_map *cpus = cpu_map__new(NULL);
 263
 264                 cpu =  cpus ? cpus->map[0] : 0;
 265                 cpu_map__put(cpus);
 266         } else {
 267                 cpu = evlist->cpus->map[0];
 268         }
 269
 270         while (1) {
 271                 fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1,
 272                                          perf_event_open_cloexec_flag());
 273                 if (fd < 0) {
 274                         if (pid == -1 && errno == EACCES) {
 275                                 pid = 0;
 276                                 continue;
 277                         }
 278                         goto out_delete;
 279                 }
 280                 break;
 281         }
 282         close(fd);
 283         ret = true;
 284
 285 out_delete:
 286         perf_evlist__delete(temp_evlist);
 287         return ret;
 288 }