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                 if (unwind__prepare_access(thread) < 0)
  47                         goto err_thread;
  48
  49                 comm_str = malloc(32);
  50                 if (!comm_str)
  51                         goto err_thread;
  52
  53                 snprintf(comm_str, 32, ":%d", tid);
  54                 comm = comm__new(comm_str, 0, false);
  55                 free(comm_str);
  56                 if (!comm)
  57                         goto err_thread;
  58
  59                 list_add(&comm->list, &thread->comm_list);
  60                 atomic_set(&thread->refcnt, 1);
  61                 RB_CLEAR_NODE(&thread->rb_node);
  62         }
  63
  64         return thread;
  65
  66 err_thread:
  67         free(thread);
  68         return NULL;
  69 }
  70
  71 void thread__delete(struct thread *thread)
  72 {
  73         struct comm *comm, *tmp;
  74
  75         BUG_ON(!RB_EMPTY_NODE(&thread->rb_node));
  76
  77         thread_stack__free(thread);
  78
  79         if (thread->mg) {
  80                 map_groups__put(thread->mg);
  81                 thread->mg = NULL;
  82         }
  83         list_for_each_entry_safe(comm, tmp, &thread->comm_list, list) {
  84                 list_del(&comm->list);
  85                 comm__free(comm);
  86         }
  87         unwind__finish_access(thread);
  88
  89         free(thread);
  90 }
  91
  92 struct thread *thread__get(struct thread *thread)
  93 {
  94         if (thread)
  95                 atomic_inc(&thread->refcnt);
  96         return thread;
  97 }
  98
  99 void thread__put(struct thread *thread)
 100 {
 101         if (thread && atomic_dec_and_test(&thread->refcnt)) {
 102                 /*
 103                  * Remove it from the dead_threads list, as last reference
 104                  * is gone.
 105                  */
 106                 list_del_init(&thread->node);
 107                 thread__delete(thread);
 108         }
 109 }
 110
 111 struct comm *thread__comm(const struct thread *thread)
 112 {
 113         if (list_empty(&thread->comm_list))
 114                 return NULL;
 115
 116         return list_first_entry(&thread->comm_list, struct comm, list);
 117 }
 118
 119 struct comm *thread__exec_comm(const struct thread *thread)
 120 {
 121         struct comm *comm, *last = NULL;
 122
 123         list_for_each_entry(comm, &thread->comm_list, list) {
 124                 if (comm->exec)
 125                         return comm;
 126                 last = comm;
 127         }
 128
 129         return last;
 130 }
 131
 132 int __thread__set_comm(struct thread *thread, const char *str, u64 timestamp,
 133                        bool exec)
 134 {
 135         struct comm *new, *curr = thread__comm(thread);
 136         int err;
 137
 138         /* Override the default :tid entry */
 139         if (!thread->comm_set) {
 140                 err = comm__override(curr, str, timestamp, exec);
 141                 if (err)
 142                         return err;
 143         } else {
 144                 new = comm__new(str, timestamp, exec);
 145                 if (!new)
 146                         return -ENOMEM;
 147                 list_add(&new->list, &thread->comm_list);
 148
 149                 if (exec)
 150                         unwind__flush_access(thread);
 151         }
 152
 153         thread->comm_set = true;
 154
 155         return 0;
 156 }
 157
 158 int thread__set_comm_from_proc(struct thread *thread)
 159 {
 160         char path[64];
 161         char *comm = NULL;
 162         size_t sz;
 163         int err = -1;
 164
 165         if (!(snprintf(path, sizeof(path), "%d/task/%d/comm",
 166                        thread->pid_, thread->tid) >= (int)sizeof(path)) &&
 167             procfs__read_str(path, &comm, &sz) == 0) {
 168                 comm[sz - 1] = '\0';
 169                 err = thread__set_comm(thread, comm, 0);
 170         }
 171
 172         return err;
 173 }
 174
 175 const char *thread__comm_str(const struct thread *thread)
 176 {
 177         const struct comm *comm = thread__comm(thread);
 178
 179         if (!comm)
 180                 return NULL;
 181
 182         return comm__str(comm);
 183 }
 184
 185 /* CHECKME: it should probably better return the max comm len from its comm list */
 186 int thread__comm_len(struct thread *thread)
 187 {
 188         if (!thread->comm_len) {
 189                 const char *comm = thread__comm_str(thread);
 190                 if (!comm)
 191                         return 0;
 192                 thread->comm_len = strlen(comm);
 193         }
 194
 195         return thread->comm_len;
 196 }
 197
 198 size_t thread__fprintf(struct thread *thread, FILE *fp)
 199 {
 200         return fprintf(fp, "Thread %d %s\n", thread->tid, thread__comm_str(thread)) +
 201                map_groups__fprintf(thread->mg, fp);
 202 }
 203
 204 void thread__insert_map(struct thread *thread, struct map *map)
 205 {
 206         map_groups__fixup_overlappings(thread->mg, map, stderr);
 207         map_groups__insert(thread->mg, map);
 208 }
 209
 210 static int thread__clone_map_groups(struct thread *thread,
 211                                     struct thread *parent)
 212 {
 213         int i;
 214
 215         /* This is new thread, we share map groups for process. */
 216         if (thread->pid_ == parent->pid_)
 217                 return 0;
 218
 219         if (thread->mg == parent->mg) {
 220                 pr_debug("broken map groups on thread %d/%d parent %d/%d\n",
 221                          thread->pid_, thread->tid, parent->pid_, parent->tid);
 222                 return 0;
 223         }
 224
 225         /* But this one is new process, copy maps. */
 226         for (i = 0; i < MAP__NR_TYPES; ++i)
 227                 if (map_groups__clone(thread->mg, parent->mg, i) < 0)
 228                         return -ENOMEM;
 229
 230         return 0;
 231 }
 232
 233 int thread__fork(struct thread *thread, struct thread *parent, u64 timestamp)
 234 {
 235         int err;
 236
 237         if (parent->comm_set) {
 238                 const char *comm = thread__comm_str(parent);
 239                 if (!comm)
 240                         return -ENOMEM;
 241                 err = thread__set_comm(thread, comm, timestamp);
 242                 if (err)
 243                         return err;
 244         }
 245
 246         thread->ppid = parent->tid;
 247         return thread__clone_map_groups(thread, parent);
 248 }
 249
 250 void thread__find_cpumode_addr_location(struct thread *thread,
 251                                         enum map_type type, u64 addr,
 252                                         struct addr_location *al)
 253 {
 254         size_t i;
 255         const u8 cpumodes[] = {
 256                 PERF_RECORD_MISC_USER,
 257                 PERF_RECORD_MISC_KERNEL,
 258                 PERF_RECORD_MISC_GUEST_USER,
 259                 PERF_RECORD_MISC_GUEST_KERNEL
 260         };
 261
 262         for (i = 0; i < ARRAY_SIZE(cpumodes); i++) {
 263                 thread__find_addr_location(thread, cpumodes[i], type, addr, al);
 264                 if (al->map)
 265                         break;
 266         }
 267 }