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->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 void perf_evlist__id_hash(struct perf_evlist *evlist, struct perf_evsel *evsel,
 110                           int cpu, int thread, u64 id)
 111 {
 112         int hash;
 113         struct perf_sample_id *sid = SID(evsel, cpu, thread);
 114
 115         sid->id = id;
 116         sid->evsel = evsel;
 117         hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
 118         hlist_add_head(&sid->node, &evlist->heads[hash]);
 119 }
 120
 121 static int perf_evlist__id_hash_fd(struct perf_evlist *evlist,
 122                                    struct perf_evsel *evsel,
 123                                    int cpu, int thread, int fd)
 124 {
 125         u64 read_data[4] = { 0, };
 126         int id_idx = 1; /* The first entry is the counter value */
 127
 128         if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
 129             read(fd, &read_data, sizeof(read_data)) == -1)
 130                 return -1;
 131
 132         if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
 133                 ++id_idx;
 134         if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
 135                 ++id_idx;
 136
 137         perf_evlist__id_hash(evlist, evsel, cpu, thread, read_data[id_idx]);
 138         return 0;
 139 }
 140
 141 struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
 142 {
 143         struct hlist_head *head;
 144         struct hlist_node *pos;
 145         struct perf_sample_id *sid;
 146         int hash;
 147
 148         if (evlist->nr_entries == 1)
 149                 return list_entry(evlist->entries.next, struct perf_evsel, node);
 150
 151         hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
 152         head = &evlist->heads[hash];
 153
 154         hlist_for_each_entry(sid, pos, head, node)
 155                 if (sid->id == id)
 156                         return sid->evsel;
 157         return NULL;
 158 }
 159
 160 union perf_event *perf_evlist__read_on_cpu(struct perf_evlist *evlist, int cpu)
 161 {
 162         /* XXX Move this to perf.c, making it generally available */
 163         unsigned int page_size = sysconf(_SC_PAGE_SIZE);
 164         struct perf_mmap *md = &evlist->mmap[cpu];
 165         unsigned int head = perf_mmap__read_head(md);
 166         unsigned int old = md->prev;
 167         unsigned char *data = md->base + page_size;
 168         union perf_event *event = NULL;
 169
 170         if (evlist->overwrite) {
 171                 /*
 172                  * If we're further behind than half the buffer, there's a chance
 173                  * the writer will bite our tail and mess up the samples under us.
 174                  *
 175                  * If we somehow ended up ahead of the head, we got messed up.
 176                  *
 177                  * In either case, truncate and restart at head.
 178                  */
 179                 int diff = head - old;
 180                 if (diff > md->mask / 2 || diff < 0) {
 181                         fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");
 182
 183                         /*
 184                          * head points to a known good entry, start there.
 185                          */
 186                         old = head;
 187                 }
 188         }
 189
 190         if (old != head) {
 191                 size_t size;
 192
 193                 event = (union perf_event *)&data[old & md->mask];
 194                 size = event->header.size;
 195
 196                 /*
 197                  * Event straddles the mmap boundary -- header should always
 198                  * be inside due to u64 alignment of output.
 199                  */
 200                 if ((old & md->mask) + size != ((old + size) & md->mask)) {
 201                         unsigned int offset = old;
 202                         unsigned int len = min(sizeof(*event), size), cpy;
 203                         void *dst = &evlist->event_copy;
 204
 205                         do {
 206                                 cpy = min(md->mask + 1 - (offset & md->mask), len);
 207                                 memcpy(dst, &data[offset & md->mask], cpy);
 208                                 offset += cpy;
 209                                 dst += cpy;
 210                                 len -= cpy;
 211                         } while (len);
 212
 213                         event = &evlist->event_copy;
 214                 }
 215
 216                 old += size;
 217         }
 218
 219         md->prev = old;
 220
 221         if (!evlist->overwrite)
 222                 perf_mmap__write_tail(md, old);
 223
 224         return event;
 225 }
 226
 227 void perf_evlist__munmap(struct perf_evlist *evlist)
 228 {
 229         int cpu;
 230
 231         for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
 232                 if (evlist->mmap[cpu].base != NULL) {
 233                         munmap(evlist->mmap[cpu].base, evlist->mmap_len);
 234                         evlist->mmap[cpu].base = NULL;
 235                 }
 236         }
 237 }
 238
 239 int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
 240 {
 241         evlist->mmap = zalloc(evlist->cpus->nr * sizeof(struct perf_mmap));
 242         return evlist->mmap != NULL ? 0 : -ENOMEM;
 243 }
 244
 245 static int __perf_evlist__mmap(struct perf_evlist *evlist, int cpu, int prot,
 246                                int mask, int fd)
 247 {
 248         evlist->mmap[cpu].prev = 0;
 249         evlist->mmap[cpu].mask = mask;
 250         evlist->mmap[cpu].base = mmap(NULL, evlist->mmap_len, prot,
 251                                       MAP_SHARED, fd, 0);
 252         if (evlist->mmap[cpu].base == MAP_FAILED)
 253                 return -1;
 254
 255         perf_evlist__add_pollfd(evlist, fd);
 256         return 0;
 257 }
 258
 259 /** perf_evlist__mmap - Create per cpu maps to receive events
 260  *
 261  * @evlist - list of events
 262  * @pages - map length in pages
 263  * @overwrite - overwrite older events?
 264  *
 265  * If overwrite is false the user needs to signal event consuption using:
 266  *
 267  *      struct perf_mmap *m = &evlist->mmap[cpu];
 268  *      unsigned int head = perf_mmap__read_head(m);
 269  *
 270  *      perf_mmap__write_tail(m, head)
 271  *
 272  * Using perf_evlist__read_on_cpu does this automatically.
 273  */
 274 int perf_evlist__mmap(struct perf_evlist *evlist, int pages, bool overwrite)
 275 {
 276         unsigned int page_size = sysconf(_SC_PAGE_SIZE);
 277         int mask = pages * page_size - 1, cpu;
 278         struct perf_evsel *first_evsel, *evsel;
 279         const struct cpu_map *cpus = evlist->cpus;
 280         const struct thread_map *threads = evlist->threads;
 281         int thread, prot = PROT_READ | (overwrite ? 0 : PROT_WRITE);
 282
 283         if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0)
 284                 return -ENOMEM;
 285
 286         if (evlist->pollfd == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
 287                 return -ENOMEM;
 288
 289         evlist->overwrite = overwrite;
 290         evlist->mmap_len = (pages + 1) * page_size;
 291         first_evsel = list_entry(evlist->entries.next, struct perf_evsel, node);
 292
 293         list_for_each_entry(evsel, &evlist->entries, node) {
 294                 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
 295                     evsel->id == NULL &&
 296                     perf_evsel__alloc_id(evsel, cpus->nr, threads->nr) < 0)
 297                         return -ENOMEM;
 298
 299                 for (cpu = 0; cpu < cpus->nr; cpu++) {
 300                         for (thread = 0; thread < threads->nr; thread++) {
 301                                 int fd = FD(evsel, cpu, thread);
 302
 303                                 if (evsel->idx || thread) {
 304                                         if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT,
 305                                                   FD(first_evsel, cpu, 0)) != 0)
 306                                                 goto out_unmap;
 307                                 } else if (__perf_evlist__mmap(evlist, cpu, prot, mask, fd) < 0)
 308                                         goto out_unmap;
 309
 310                                 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
 311                                     perf_evlist__id_hash_fd(evlist, evsel, cpu, thread, fd) < 0)
 312                                         goto out_unmap;
 313                         }
 314                 }
 315         }
 316
 317         return 0;
 318
 319 out_unmap:
 320         for (cpu = 0; cpu < cpus->nr; cpu++) {
 321                 if (evlist->mmap[cpu].base != NULL) {
 322                         munmap(evlist->mmap[cpu].base, evlist->mmap_len);
 323                         evlist->mmap[cpu].base = NULL;
 324                 }
 325         }
 326         return -1;
 327 }
 328
 329 int perf_evlist__create_maps(struct perf_evlist *evlist, pid_t target_pid,
 330                              pid_t target_tid, const char *cpu_list)
 331 {
 332         evlist->threads = thread_map__new(target_pid, target_tid);
 333
 334         if (evlist->threads == NULL)
 335                 return -1;
 336
 337         if (target_tid != -1)
 338                 evlist->cpus = cpu_map__dummy_new();
 339         else
 340                 evlist->cpus = cpu_map__new(cpu_list);
 341
 342         if (evlist->cpus == NULL)
 343                 goto out_delete_threads;
 344
 345         return 0;
 346
 347 out_delete_threads:
 348         thread_map__delete(evlist->threads);
 349         return -1;
 350 }
 351
 352 void perf_evlist__delete_maps(struct perf_evlist *evlist)
 353 {
 354         cpu_map__delete(evlist->cpus);
 355         thread_map__delete(evlist->threads);
 356         evlist->cpus    = NULL;
 357         evlist->threads = NULL;
 358 }
 359
 360 int perf_evlist__set_filters(struct perf_evlist *evlist)
 361 {
 362         const struct thread_map *threads = evlist->threads;
 363         const struct cpu_map *cpus = evlist->cpus;
 364         struct perf_evsel *evsel;
 365         char *filter;
 366         int thread;
 367         int cpu;
 368         int err;
 369         int fd;
 370
 371         list_for_each_entry(evsel, &evlist->entries, node) {
 372                 filter = evsel->filter;
 373                 if (!filter)
 374                         continue;
 375                 for (cpu = 0; cpu < cpus->nr; cpu++) {
 376                         for (thread = 0; thread < threads->nr; thread++) {
 377                                 fd = FD(evsel, cpu, thread);
 378                                 err = ioctl(fd, PERF_EVENT_IOC_SET_FILTER, filter);
 379                                 if (err)
 380                                         return err;
 381                         }
 382                 }
 383         }
 384
 385         return 0;
 386 }