tools/perf/util/evlist.c

   1 /*
   2  * Copyright (C) 2011, Red Hat Inc, Arnaldo Carvalho de Melo <acme@redhat.com>
   3  *
   4  * Parts came from builtin-{top,stat,record}.c, see those files for further
   5  * copyright notes.
   6  *
   7  * Released under the GPL v2. (and only v2, not any later version)
   8  */
   9 #include <poll.h>
  10 #include "cpumap.h"
  11 #include "thread_map.h"
  12 #include "evlist.h"
  13 #include "evsel.h"
  14 #include "util.h"
  15 #include "debug.h"
  16
  17 #include <sys/mman.h>
  18
  19 #include <linux/bitops.h>
  20 #include <linux/hash.h>
  21
  22 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
  23 #define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
  24
  25 void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
  26                        struct thread_map *threads)
  27 {
  28         int i;
  29
  30         for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
  31                 INIT_HLIST_HEAD(&evlist->heads[i]);
  32         INIT_LIST_HEAD(&evlist->entries);
  33         perf_evlist__set_maps(evlist, cpus, threads);
  34 }
  35
  36 struct perf_evlist *perf_evlist__new(struct cpu_map *cpus,
  37                                      struct thread_map *threads)
  38 {
  39         struct perf_evlist *evlist = zalloc(sizeof(*evlist));
  40
  41         if (evlist != NULL)
  42                 perf_evlist__init(evlist, cpus, threads);
  43
  44         return evlist;
  45 }
  46
  47 static void perf_evlist__purge(struct perf_evlist *evlist)
  48 {
  49         struct perf_evsel *pos, *n;
  50
  51         list_for_each_entry_safe(pos, n, &evlist->entries, node) {
  52                 list_del_init(&pos->node);
  53                 perf_evsel__delete(pos);
  54         }
  55
  56         evlist->nr_entries = 0;
  57 }
  58
  59 void perf_evlist__exit(struct perf_evlist *evlist)
  60 {
  61         free(evlist->mmap);
  62         free(evlist->pollfd);
  63         evlist->mmap = NULL;
  64         evlist->pollfd = NULL;
  65 }
  66
  67 void perf_evlist__delete(struct perf_evlist *evlist)
  68 {
  69         perf_evlist__purge(evlist);
  70         perf_evlist__exit(evlist);
  71         free(evlist);
  72 }
  73
  74 void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry)
  75 {
  76         list_add_tail(&entry->node, &evlist->entries);
  77         ++evlist->nr_entries;
  78 }
  79
  80 int perf_evlist__add_default(struct perf_evlist *evlist)
  81 {
  82         struct perf_event_attr attr = {
  83                 .type = PERF_TYPE_HARDWARE,
  84                 .config = PERF_COUNT_HW_CPU_CYCLES,
  85         };
  86         struct perf_evsel *evsel = perf_evsel__new(&attr, 0);
  87
  88         if (evsel == NULL)
  89                 return -ENOMEM;
  90
  91         perf_evlist__add(evlist, evsel);
  92         return 0;
  93 }
  94
  95 int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
  96 {
  97         int nfds = evlist->cpus->nr * evlist->threads->nr * evlist->nr_entries;
  98         evlist->pollfd = malloc(sizeof(struct pollfd) * nfds);
  99         return evlist->pollfd != NULL ? 0 : -ENOMEM;
 100 }
 101
 102 void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd)
 103 {
 104         fcntl(fd, F_SETFL, O_NONBLOCK);
 105         evlist->pollfd[evlist->nr_fds].fd = fd;
 106         evlist->pollfd[evlist->nr_fds].events = POLLIN;
 107         evlist->nr_fds++;
 108 }
 109
 110 static void perf_evlist__id_hash(struct perf_evlist *evlist,
 111                                  struct perf_evsel *evsel,
 112                                  int cpu, int thread, u64 id)
 113 {
 114         int hash;
 115         struct perf_sample_id *sid = SID(evsel, cpu, thread);
 116
 117         sid->id = id;
 118         sid->evsel = evsel;
 119         hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
 120         hlist_add_head(&sid->node, &evlist->heads[hash]);
 121 }
 122
 123 void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel,
 124                          int cpu, int thread, u64 id)
 125 {
 126         perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
 127         evsel->id[evsel->ids++] = id;
 128 }
 129
 130 static int perf_evlist__id_add_fd(struct perf_evlist *evlist,
 131                                   struct perf_evsel *evsel,
 132                                   int cpu, int thread, int fd)
 133 {
 134         u64 read_data[4] = { 0, };
 135         int id_idx = 1; /* The first entry is the counter value */
 136
 137         if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
 138             read(fd, &read_data, sizeof(read_data)) == -1)
 139                 return -1;
 140
 141         if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
 142                 ++id_idx;
 143         if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
 144                 ++id_idx;
 145
 146         perf_evlist__id_add(evlist, evsel, cpu, thread, read_data[id_idx]);
 147         return 0;
 148 }
 149
 150 struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
 151 {
 152         struct hlist_head *head;
 153         struct hlist_node *pos;
 154         struct perf_sample_id *sid;
 155         int hash;
 156
 157         if (evlist->nr_entries == 1)
 158                 return list_entry(evlist->entries.next, struct perf_evsel, node);
 159
 160         hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
 161         head = &evlist->heads[hash];
 162
 163         hlist_for_each_entry(sid, pos, head, node)
 164                 if (sid->id == id)
 165                         return sid->evsel;
 166         return NULL;
 167 }
 168
 169 union perf_event *perf_evlist__read_on_cpu(struct perf_evlist *evlist, int cpu)
 170 {
 171         /* XXX Move this to perf.c, making it generally available */
 172         unsigned int page_size = sysconf(_SC_PAGE_SIZE);
 173         struct perf_mmap *md = &evlist->mmap[cpu];
 174         unsigned int head = perf_mmap__read_head(md);
 175         unsigned int old = md->prev;
 176         unsigned char *data = md->base + page_size;
 177         union perf_event *event = NULL;
 178
 179         if (evlist->overwrite) {
 180                 /*
 181                  * If we're further behind than half the buffer, there's a chance
 182                  * the writer will bite our tail and mess up the samples under us.
 183                  *
 184                  * If we somehow ended up ahead of the head, we got messed up.
 185                  *
 186                  * In either case, truncate and restart at head.
 187                  */
 188                 int diff = head - old;
 189                 if (diff > md->mask / 2 || diff < 0) {
 190                         fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");
 191
 192                         /*
 193                          * head points to a known good entry, start there.
 194                          */
 195                         old = head;
 196                 }
 197         }
 198
 199         if (old != head) {
 200                 size_t size;
 201
 202                 event = (union perf_event *)&data[old & md->mask];
 203                 size = event->header.size;
 204
 205                 /*
 206                  * Event straddles the mmap boundary -- header should always
 207                  * be inside due to u64 alignment of output.
 208                  */
 209                 if ((old & md->mask) + size != ((old + size) & md->mask)) {
 210                         unsigned int offset = old;
 211                         unsigned int len = min(sizeof(*event), size), cpy;
 212                         void *dst = &evlist->event_copy;
 213
 214                         do {
 215                                 cpy = min(md->mask + 1 - (offset & md->mask), len);
 216                                 memcpy(dst, &data[offset & md->mask], cpy);
 217                                 offset += cpy;
 218                                 dst += cpy;
 219                                 len -= cpy;
 220                         } while (len);
 221
 222                         event = &evlist->event_copy;
 223                 }
 224
 225                 old += size;
 226         }
 227
 228         md->prev = old;
 229
 230         if (!evlist->overwrite)
 231                 perf_mmap__write_tail(md, old);
 232
 233         return event;
 234 }
 235
 236 void perf_evlist__munmap(struct perf_evlist *evlist)
 237 {
 238         int cpu;
 239
 240         for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
 241                 if (evlist->mmap[cpu].base != NULL) {
 242                         munmap(evlist->mmap[cpu].base, evlist->mmap_len);
 243                         evlist->mmap[cpu].base = NULL;
 244                 }
 245         }
 246 }
 247
 248 int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
 249 {
 250         evlist->mmap = zalloc(evlist->cpus->nr * sizeof(struct perf_mmap));
 251         return evlist->mmap != NULL ? 0 : -ENOMEM;
 252 }
 253
 254 static int __perf_evlist__mmap(struct perf_evlist *evlist, struct perf_evsel *evsel,
 255                                int cpu, int prot, int mask, int fd)
 256 {
 257         evlist->mmap[cpu].prev = 0;
 258         evlist->mmap[cpu].mask = mask;
 259         evlist->mmap[cpu].base = mmap(NULL, evlist->mmap_len, prot,
 260                                       MAP_SHARED, fd, 0);
 261         if (evlist->mmap[cpu].base == MAP_FAILED) {
 262                 if (evlist->cpus->map[cpu] == -1 && evsel->attr.inherit)
 263                         ui__warning("Inherit is not allowed on per-task "
 264                                     "events using mmap.\n");
 265                 return -1;
 266         }
 267
 268         perf_evlist__add_pollfd(evlist, fd);
 269         return 0;
 270 }
 271
 272 /** perf_evlist__mmap - Create per cpu maps to receive events
 273  *
 274  * @evlist - list of events
 275  * @pages - map length in pages
 276  * @overwrite - overwrite older events?
 277  *
 278  * If overwrite is false the user needs to signal event consuption using:
 279  *
 280  *      struct perf_mmap *m = &evlist->mmap[cpu];
 281  *      unsigned int head = perf_mmap__read_head(m);
 282  *
 283  *      perf_mmap__write_tail(m, head)
 284  *
 285  * Using perf_evlist__read_on_cpu does this automatically.
 286  */
 287 int perf_evlist__mmap(struct perf_evlist *evlist, int pages, bool overwrite)
 288 {
 289         unsigned int page_size = sysconf(_SC_PAGE_SIZE);
 290         int mask = pages * page_size - 1, cpu;
 291         struct perf_evsel *first_evsel, *evsel;
 292         const struct cpu_map *cpus = evlist->cpus;
 293         const struct thread_map *threads = evlist->threads;
 294         int thread, prot = PROT_READ | (overwrite ? 0 : PROT_WRITE);
 295
 296         if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0)
 297                 return -ENOMEM;
 298
 299         if (evlist->pollfd == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
 300                 return -ENOMEM;
 301
 302         evlist->overwrite = overwrite;
 303         evlist->mmap_len = (pages + 1) * page_size;
 304         first_evsel = list_entry(evlist->entries.next, struct perf_evsel, node);
 305
 306         list_for_each_entry(evsel, &evlist->entries, node) {
 307                 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
 308                     evsel->sample_id == NULL &&
 309                     perf_evsel__alloc_id(evsel, cpus->nr, threads->nr) < 0)
 310                         return -ENOMEM;
 311
 312                 for (cpu = 0; cpu < cpus->nr; cpu++) {
 313                         for (thread = 0; thread < threads->nr; thread++) {
 314                                 int fd = FD(evsel, cpu, thread);
 315
 316                                 if (evsel->idx || thread) {
 317                                         if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT,
 318                                                   FD(first_evsel, cpu, 0)) != 0)
 319                                                 goto out_unmap;
 320                                 } else if (__perf_evlist__mmap(evlist, evsel, cpu,
 321                                                                prot, mask, fd) < 0)
 322                                         goto out_unmap;
 323
 324                                 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
 325                                     perf_evlist__id_add_fd(evlist, evsel, cpu, thread, fd) < 0)
 326                                         goto out_unmap;
 327                         }
 328                 }
 329         }
 330
 331         return 0;
 332
 333 out_unmap:
 334         for (cpu = 0; cpu < cpus->nr; cpu++) {
 335                 if (evlist->mmap[cpu].base != NULL) {
 336                         munmap(evlist->mmap[cpu].base, evlist->mmap_len);
 337                         evlist->mmap[cpu].base = NULL;
 338                 }
 339         }
 340         return -1;
 341 }
 342
 343 int perf_evlist__create_maps(struct perf_evlist *evlist, pid_t target_pid,
 344                              pid_t target_tid, const char *cpu_list)
 345 {
 346         evlist->threads = thread_map__new(target_pid, target_tid);
 347
 348         if (evlist->threads == NULL)
 349                 return -1;
 350
 351         if (cpu_list == NULL && target_tid != -1)
 352                 evlist->cpus = cpu_map__dummy_new();
 353         else
 354                 evlist->cpus = cpu_map__new(cpu_list);
 355
 356         if (evlist->cpus == NULL)
 357                 goto out_delete_threads;
 358
 359         return 0;
 360
 361 out_delete_threads:
 362         thread_map__delete(evlist->threads);
 363         return -1;
 364 }
 365
 366 void perf_evlist__delete_maps(struct perf_evlist *evlist)
 367 {
 368         cpu_map__delete(evlist->cpus);
 369         thread_map__delete(evlist->threads);
 370         evlist->cpus    = NULL;
 371         evlist->threads = NULL;
 372 }
 373
 374 int perf_evlist__set_filters(struct perf_evlist *evlist)
 375 {
 376         const struct thread_map *threads = evlist->threads;
 377         const struct cpu_map *cpus = evlist->cpus;
 378         struct perf_evsel *evsel;
 379         char *filter;
 380         int thread;
 381         int cpu;
 382         int err;
 383         int fd;
 384
 385         list_for_each_entry(evsel, &evlist->entries, node) {
 386                 filter = evsel->filter;
 387                 if (!filter)
 388                         continue;
 389                 for (cpu = 0; cpu < cpus->nr; cpu++) {
 390                         for (thread = 0; thread < threads->nr; thread++) {
 391                                 fd = FD(evsel, cpu, thread);
 392                                 err = ioctl(fd, PERF_EVENT_IOC_SET_FILTER, filter);
 393                                 if (err)
 394                                         return err;
 395                         }
 396                 }
 397         }
 398
 399         return 0;
 400 }