kernel/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))
  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__delete(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 bool perf_can_sample_identifier(void)
  89 {
  90         return perf_probe_api(perf_probe_sample_identifier);
  91 }
  92
  93 static bool perf_can_comm_exec(void)
  94 {
  95         return perf_probe_api(perf_probe_comm_exec);
  96 }
  97
  98 void perf_evlist__config(struct perf_evlist *evlist, struct record_opts *opts)
  99 {
 100         struct perf_evsel *evsel;
 101         bool use_sample_identifier = false;
 102         bool use_comm_exec;
 103
 104         /*
 105          * Set the evsel leader links before we configure attributes,
 106          * since some might depend on this info.
 107          */
 108         if (opts->group)
 109                 perf_evlist__set_leader(evlist);
 110
 111         if (evlist->cpus->map[0] < 0)
 112                 opts->no_inherit = true;
 113
 114         use_comm_exec = perf_can_comm_exec();
 115
 116         evlist__for_each(evlist, evsel) {
 117                 perf_evsel__config(evsel, opts);
 118                 if (evsel->tracking && use_comm_exec)
 119                         evsel->attr.comm_exec = 1;
 120         }
 121
 122         if (evlist->nr_entries > 1) {
 123                 struct perf_evsel *first = perf_evlist__first(evlist);
 124
 125                 evlist__for_each(evlist, evsel) {
 126                         if (evsel->attr.sample_type == first->attr.sample_type)
 127                                 continue;
 128                         use_sample_identifier = perf_can_sample_identifier();
 129                         break;
 130                 }
 131                 evlist__for_each(evlist, evsel)
 132                         perf_evsel__set_sample_id(evsel, use_sample_identifier);
 133         }
 134
 135         perf_evlist__set_id_pos(evlist);
 136 }
 137
 138 static int get_max_rate(unsigned int *rate)
 139 {
 140         return sysctl__read_int("kernel/perf_event_max_sample_rate", (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         pid_t pid = -1;
 205
 206         temp_evlist = perf_evlist__new();
 207         if (!temp_evlist)
 208                 return false;
 209
 210         err = parse_events(temp_evlist, str);
 211         if (err)
 212                 goto out_delete;
 213
 214         evsel = perf_evlist__last(temp_evlist);
 215
 216         if (!evlist || cpu_map__empty(evlist->cpus)) {
 217                 struct cpu_map *cpus = cpu_map__new(NULL);
 218
 219                 cpu =  cpus ? cpus->map[0] : 0;
 220                 cpu_map__delete(cpus);
 221         } else {
 222                 cpu = evlist->cpus->map[0];
 223         }
 224
 225         while (1) {
 226                 fd = sys_perf_event_open(&evsel->attr, pid, cpu, -1,
 227                                          perf_event_open_cloexec_flag());
 228                 if (fd < 0) {
 229                         if (pid == -1 && errno == EACCES) {
 230                                 pid = 0;
 231                                 continue;
 232                         }
 233                         goto out_delete;
 234                 }
 235                 break;
 236         }
 237         close(fd);
 238         ret = true;
 239
 240 out_delete:
 241         perf_evlist__delete(temp_evlist);
 242         return ret;
 243 }