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