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 } 235