tools/perf/util/thread.c

   1 #include "../perf.h"
   2 #include <stdlib.h>
   3 #include <stdio.h>
   4 #include <string.h>
   5 #include "session.h"
   6 #include "thread.h"
   7 #include "thread-stack.h"
   8 #include "util.h"
   9 #include "debug.h"
  10 #include "comm.h"
  11 #include "unwind.h"
  12
  13 #include <api/fs/fs.h>
  14
  15 int thread__init_map_groups(struct thread *thread, struct machine *machine)
  16 {
  17         struct thread *leader;
  18         pid_t pid = thread->pid_;
  19
  20         if (pid == thread->tid || pid == -1) {
  21                 thread->mg = map_groups__new(machine);
  22         } else {
  23                 leader = __machine__findnew_thread(machine, pid, pid);
  24                 if (leader) {
  25                         thread->mg = map_groups__get(leader->mg);
  26                         thread__put(leader);
  27                 }
  28         }
  29
  30         return thread->mg ? 0 : -1;
  31 }
  32
  33 struct thread *thread__new(pid_t pid, pid_t tid)
  34 {
  35         char *comm_str;
  36         struct comm *comm;
  37         struct thread *thread = zalloc(sizeof(*thread));
  38
  39         if (thread != NULL) {
  40                 thread->pid_ = pid;
  41                 thread->tid = tid;
  42                 thread->ppid = -1;
  43                 thread->cpu = -1;
  44                 INIT_LIST_HEAD(&thread->comm_list);
  45
  46                 comm_str = malloc(32);
  47                 if (!comm_str)
  48                         goto err_thread;
  49
  50                 snprintf(comm_str, 32, ":%d", tid);
  51                 comm = comm__new(comm_str, 0, false);
  52                 free(comm_str);
  53                 if (!comm)
  54                         goto err_thread;
  55
  56                 list_add(&comm->list, &thread->comm_list);
  57                 atomic_set(&thread->refcnt, 1);
  58                 RB_CLEAR_NODE(&thread->rb_node);
  59         }
  60
  61         return thread;
  62
  63 err_thread:
  64         free(thread);
  65         return NULL;
  66 }
  67
  68 void thread__delete(struct thread *thread)
  69 {
  70         struct comm *comm, *tmp;
  71
  72         BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
  73
  74         thread_stack__free(thread);
  75
  76         if (thread->mg) {
  77                 map_groups__put(thread->mg);
  78                 thread->mg = NULL;
  79         }
  80         list_for_each_entry_safe(comm, tmp, &thread->comm_list, list) {
  81                 list_del(&comm->list);
  82                 comm__free(comm);
  83         }
  84         unwind__finish_access(thread);
  85
  86         free(thread);
  87 }
  88
  89 struct thread *thread__get(struct thread *thread)
  90 {
  91         if (thread)
  92                 atomic_inc(&thread->refcnt);
  93         return thread;
  94 }
  95
  96 void thread__put(struct thread *thread)
  97 {
  98         if (thread && atomic_dec_and_test(&thread->refcnt)) {
  99                 /*
 100                  * Remove it from the dead_threads list, as last reference
 101                  * is gone.
 102                  */
 103                 list_del_init(&thread->node);
 104                 thread__delete(thread);
 105         }
 106 }
 107
 108 struct comm *thread__comm(const struct thread *thread)
 109 {
 110         if (list_empty(&thread->comm_list))
 111                 return NULL;
 112
 113         return list_first_entry(&thread->comm_list, struct comm, list);
 114 }
 115
 116 struct comm *thread__exec_comm(const struct thread *thread)
 117 {
 118         struct comm *comm, *last = NULL;
 119
 120         list_for_each_entry(comm, &thread->comm_list, list) {
 121                 if (comm->exec)
 122                         return comm;
 123                 last = comm;
 124         }
 125
 126         return last;
 127 }
 128
 129 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
 130                        bool exec)
 131 {
 132         struct comm *new, *curr = thread__comm(thread);
 133         int err;
 134
 135         /* Override the default :tid entry */
 136         if (!thread->comm_set) {
 137                 err = comm__override(curr, str, timestamp, exec);
 138                 if (err)
 139                         return err;
 140         } else {
 141                 new = comm__new(str, timestamp, exec);
 142                 if (!new)
 143                         return -ENOMEM;
 144                 list_add(&new->list, &thread->comm_list);
 145
 146                 if (exec)
 147                         unwind__flush_access(thread);
 148         }
 149
 150         thread->comm_set = true;
 151
 152         return 0;
 153 }
 154
 155 int thread__set_comm_from_proc(struct thread *thread)
 156 {
 157         char path[64];
 158         char *comm = NULL;
 159         size_t sz;
 160         int err = -1;
 161
 162         if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
 163                        thread->pid_, thread->tid) >= (int)sizeof(path)) &&
 164             procfs__read_str(path, &comm, &sz) == 0) {
 165                 comm[sz - 1] = '\0';
 166                 err = thread__set_comm(thread, comm, 0);
 167         }
 168
 169         return err;
 170 }
 171
 172 const char *thread__comm_str(const struct thread *thread)
 173 {
 174         const struct comm *comm = thread__comm(thread);
 175
 176         if (!comm)
 177                 return NULL;
 178
 179         return comm__str(comm);
 180 }
 181
 182 /* CHECKME: it should probably better return the max comm len from its comm list */
 183 int thread__comm_len(struct thread *thread)
 184 {
 185         if (!thread->comm_len) {
 186                 const char *comm = thread__comm_str(thread);
 187                 if (!comm)
 188                         return 0;
 189                 thread->comm_len = strlen(comm);
 190         }
 191
 192         return thread->comm_len;
 193 }
 194
 195 size_t thread__fprintf(struct thread *thread, FILE *fp)
 196 {
 197         return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
 198                map_groups__fprintf(thread->mg, fp);
 199 }
 200
 201 int thread__insert_map(struct thread *thread, struct map *map)
 202 {
 203         int ret;
 204
 205         ret = unwind__prepare_access(thread, map, NULL);
 206         if (ret)
 207                 return ret;
 208
 209         map_groups__fixup_overlappings(thread->mg, map, stderr);
 210         map_groups__insert(thread->mg, map);
 211
 212         return 0;
 213 }
 214
 215 static int __thread__prepare_access(struct thread *thread)
 216 {
 217         bool initialized = false;
 218         int i, err = 0;
 219
 220         for (i = 0; i < MAP__NR_TYPES; ++i) {
 221                 struct maps *maps = &thread->mg->maps[i];
 222                 struct map *map;
 223
 224                 pthread_rwlock_rdlock(&maps->lock);
 225
 226                 for (map = maps__first(maps); map; map = map__next(map)) {
 227                         err = unwind__prepare_access(thread, map, &initialized);
 228                         if (err || initialized)
 229                                 break;
 230                 }
 231
 232                 pthread_rwlock_unlock(&maps->lock);
 233         }
 234
 235         return err;
 236 }
 237
 238 static int thread__prepare_access(struct thread *thread)
 239 {
 240         int err = 0;
 241
 242         if (symbol_conf.use_callchain)
 243                 err = __thread__prepare_access(thread);
 244
 245         return err;
 246 }
 247
 248 static int thread__clone_map_groups(struct thread *thread,
 249                                     struct thread *parent)
 250 {
 251         int i;
 252
 253         /* This is new thread, we share map groups for process. */
 254         if (thread->pid_ == parent->pid_)
 255                 return thread__prepare_access(thread);
 256
 257         if (thread->mg == parent->mg) {
 258                 pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
 259                          thread->pid_, thread->tid, parent->pid_, parent->tid);
 260                 return 0;
 261         }
 262
 263         /* But this one is new process, copy maps. */
 264         for (i = 0; i < MAP__NR_TYPES; ++i)
 265                 if (map_groups__clone(thread, parent->mg, i) < 0)
 266                         return -ENOMEM;
 267
 268         return 0;
 269 }
 270
 271 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
 272 {
 273         int err;
 274
 275         if (parent->comm_set) {
 276                 const char *comm = thread__comm_str(parent);
 277                 if (!comm)
 278                         return -ENOMEM;
 279                 err = thread__set_comm(thread, comm, timestamp);
 280                 if (err)
 281                         return err;
 282         }
 283
 284         thread->ppid = parent->tid;
 285         return thread__clone_map_groups(thread, parent);
 286 }
 287
 288 void thread__find_cpumode_addr_location(struct thread *thread,
 289                                         enum map_type type, u64 addr,
 290                                         struct addr_location *al)
 291 {
 292         size_t i;
 293         const u8 cpumodes[] = {
 294                 PERF_RECORD_MISC_USER,
 295                 PERF_RECORD_MISC_KERNEL,
 296                 PERF_RECORD_MISC_GUEST_USER,
 297                 PERF_RECORD_MISC_GUEST_KERNEL
 298         };
 299
 300         for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
 301                 thread__find_addr_location(thread, cpumodes[i], type, addr, al);
 302                 if (al->map)
 303                         break;
 304         }
 305 }
 306
 307 struct thread *thread__main_thread(struct machine *machine, struct thread *thread)
 308 {
 309         if (thread->pid_ == thread->tid)
 310                 return thread__get(thread);
 311
 312         if (thread->pid_ == -1)
 313                 return NULL;
 314
 315         return machine__find_thread(machine, thread->pid_, thread->pid_);
 316 }