profiling: Remove unused timer hook
[~shefty/rdma-dev.git] / 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 "util.h"
10 #include "debugfs.h"
11 #include <poll.h>
12 #include "cpumap.h"
13 #include "thread_map.h"
14 #include "target.h"
15 #include "evlist.h"
16 #include "evsel.h"
17 #include <unistd.h>
18
19 #include "parse-events.h"
20
21 #include <sys/mman.h>
22
23 #include <linux/bitops.h>
24 #include <linux/hash.h>
25
26 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
27 #define SID(e, x, y) xyarray__entry(e->sample_id, x, y)
28
29 void perf_evlist__init(struct perf_evlist *evlist, struct cpu_map *cpus,
30                        struct thread_map *threads)
31 {
32         int i;
33
34         for (i = 0; i < PERF_EVLIST__HLIST_SIZE; ++i)
35                 INIT_HLIST_HEAD(&evlist->heads[i]);
36         INIT_LIST_HEAD(&evlist->entries);
37         perf_evlist__set_maps(evlist, cpus, threads);
38         evlist->workload.pid = -1;
39 }
40
41 struct perf_evlist *perf_evlist__new(struct cpu_map *cpus,
42                                      struct thread_map *threads)
43 {
44         struct perf_evlist *evlist = zalloc(sizeof(*evlist));
45
46         if (evlist != NULL)
47                 perf_evlist__init(evlist, cpus, threads);
48
49         return evlist;
50 }
51
52 void perf_evlist__config_attrs(struct perf_evlist *evlist,
53                                struct perf_record_opts *opts)
54 {
55         struct perf_evsel *evsel;
56
57         if (evlist->cpus->map[0] < 0)
58                 opts->no_inherit = true;
59
60         list_for_each_entry(evsel, &evlist->entries, node) {
61                 perf_evsel__config(evsel, opts);
62
63                 if (evlist->nr_entries > 1)
64                         evsel->attr.sample_type |= PERF_SAMPLE_ID;
65         }
66 }
67
68 static void perf_evlist__purge(struct perf_evlist *evlist)
69 {
70         struct perf_evsel *pos, *n;
71
72         list_for_each_entry_safe(pos, n, &evlist->entries, node) {
73                 list_del_init(&pos->node);
74                 perf_evsel__delete(pos);
75         }
76
77         evlist->nr_entries = 0;
78 }
79
80 void perf_evlist__exit(struct perf_evlist *evlist)
81 {
82         free(evlist->mmap);
83         free(evlist->pollfd);
84         evlist->mmap = NULL;
85         evlist->pollfd = NULL;
86 }
87
88 void perf_evlist__delete(struct perf_evlist *evlist)
89 {
90         perf_evlist__purge(evlist);
91         perf_evlist__exit(evlist);
92         free(evlist);
93 }
94
95 void perf_evlist__add(struct perf_evlist *evlist, struct perf_evsel *entry)
96 {
97         list_add_tail(&entry->node, &evlist->entries);
98         ++evlist->nr_entries;
99 }
100
101 void perf_evlist__splice_list_tail(struct perf_evlist *evlist,
102                                    struct list_head *list,
103                                    int nr_entries)
104 {
105         list_splice_tail(list, &evlist->entries);
106         evlist->nr_entries += nr_entries;
107 }
108
109 void __perf_evlist__set_leader(struct list_head *list)
110 {
111         struct perf_evsel *evsel, *leader;
112
113         leader = list_entry(list->next, struct perf_evsel, node);
114         leader->leader = NULL;
115
116         list_for_each_entry(evsel, list, node) {
117                 if (evsel != leader)
118                         evsel->leader = leader;
119         }
120 }
121
122 void perf_evlist__set_leader(struct perf_evlist *evlist)
123 {
124         if (evlist->nr_entries)
125                 __perf_evlist__set_leader(&evlist->entries);
126 }
127
128 int perf_evlist__add_default(struct perf_evlist *evlist)
129 {
130         struct perf_event_attr attr = {
131                 .type = PERF_TYPE_HARDWARE,
132                 .config = PERF_COUNT_HW_CPU_CYCLES,
133         };
134         struct perf_evsel *evsel;
135
136         event_attr_init(&attr);
137
138         evsel = perf_evsel__new(&attr, 0);
139         if (evsel == NULL)
140                 goto error;
141
142         /* use strdup() because free(evsel) assumes name is allocated */
143         evsel->name = strdup("cycles");
144         if (!evsel->name)
145                 goto error_free;
146
147         perf_evlist__add(evlist, evsel);
148         return 0;
149 error_free:
150         perf_evsel__delete(evsel);
151 error:
152         return -ENOMEM;
153 }
154
155 static int perf_evlist__add_attrs(struct perf_evlist *evlist,
156                                   struct perf_event_attr *attrs, size_t nr_attrs)
157 {
158         struct perf_evsel *evsel, *n;
159         LIST_HEAD(head);
160         size_t i;
161
162         for (i = 0; i < nr_attrs; i++) {
163                 evsel = perf_evsel__new(attrs + i, evlist->nr_entries + i);
164                 if (evsel == NULL)
165                         goto out_delete_partial_list;
166                 list_add_tail(&evsel->node, &head);
167         }
168
169         perf_evlist__splice_list_tail(evlist, &head, nr_attrs);
170
171         return 0;
172
173 out_delete_partial_list:
174         list_for_each_entry_safe(evsel, n, &head, node)
175                 perf_evsel__delete(evsel);
176         return -1;
177 }
178
179 int __perf_evlist__add_default_attrs(struct perf_evlist *evlist,
180                                      struct perf_event_attr *attrs, size_t nr_attrs)
181 {
182         size_t i;
183
184         for (i = 0; i < nr_attrs; i++)
185                 event_attr_init(attrs + i);
186
187         return perf_evlist__add_attrs(evlist, attrs, nr_attrs);
188 }
189
190 struct perf_evsel *
191 perf_evlist__find_tracepoint_by_id(struct perf_evlist *evlist, int id)
192 {
193         struct perf_evsel *evsel;
194
195         list_for_each_entry(evsel, &evlist->entries, node) {
196                 if (evsel->attr.type   == PERF_TYPE_TRACEPOINT &&
197                     (int)evsel->attr.config == id)
198                         return evsel;
199         }
200
201         return NULL;
202 }
203
204 int perf_evlist__add_newtp(struct perf_evlist *evlist,
205                            const char *sys, const char *name, void *handler)
206 {
207         struct perf_evsel *evsel;
208
209         evsel = perf_evsel__newtp(sys, name, evlist->nr_entries);
210         if (evsel == NULL)
211                 return -1;
212
213         evsel->handler.func = handler;
214         perf_evlist__add(evlist, evsel);
215         return 0;
216 }
217
218 void perf_evlist__disable(struct perf_evlist *evlist)
219 {
220         int cpu, thread;
221         struct perf_evsel *pos;
222
223         for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
224                 list_for_each_entry(pos, &evlist->entries, node) {
225                         if (perf_evsel__is_group_member(pos))
226                                 continue;
227                         for (thread = 0; thread < evlist->threads->nr; thread++)
228                                 ioctl(FD(pos, cpu, thread),
229                                       PERF_EVENT_IOC_DISABLE, 0);
230                 }
231         }
232 }
233
234 void perf_evlist__enable(struct perf_evlist *evlist)
235 {
236         int cpu, thread;
237         struct perf_evsel *pos;
238
239         for (cpu = 0; cpu < cpu_map__nr(evlist->cpus); cpu++) {
240                 list_for_each_entry(pos, &evlist->entries, node) {
241                         if (perf_evsel__is_group_member(pos))
242                                 continue;
243                         for (thread = 0; thread < evlist->threads->nr; thread++)
244                                 ioctl(FD(pos, cpu, thread),
245                                       PERF_EVENT_IOC_ENABLE, 0);
246                 }
247         }
248 }
249
250 static int perf_evlist__alloc_pollfd(struct perf_evlist *evlist)
251 {
252         int nfds = cpu_map__nr(evlist->cpus) * evlist->threads->nr * evlist->nr_entries;
253         evlist->pollfd = malloc(sizeof(struct pollfd) * nfds);
254         return evlist->pollfd != NULL ? 0 : -ENOMEM;
255 }
256
257 void perf_evlist__add_pollfd(struct perf_evlist *evlist, int fd)
258 {
259         fcntl(fd, F_SETFL, O_NONBLOCK);
260         evlist->pollfd[evlist->nr_fds].fd = fd;
261         evlist->pollfd[evlist->nr_fds].events = POLLIN;
262         evlist->nr_fds++;
263 }
264
265 static void perf_evlist__id_hash(struct perf_evlist *evlist,
266                                  struct perf_evsel *evsel,
267                                  int cpu, int thread, u64 id)
268 {
269         int hash;
270         struct perf_sample_id *sid = SID(evsel, cpu, thread);
271
272         sid->id = id;
273         sid->evsel = evsel;
274         hash = hash_64(sid->id, PERF_EVLIST__HLIST_BITS);
275         hlist_add_head(&sid->node, &evlist->heads[hash]);
276 }
277
278 void perf_evlist__id_add(struct perf_evlist *evlist, struct perf_evsel *evsel,
279                          int cpu, int thread, u64 id)
280 {
281         perf_evlist__id_hash(evlist, evsel, cpu, thread, id);
282         evsel->id[evsel->ids++] = id;
283 }
284
285 static int perf_evlist__id_add_fd(struct perf_evlist *evlist,
286                                   struct perf_evsel *evsel,
287                                   int cpu, int thread, int fd)
288 {
289         u64 read_data[4] = { 0, };
290         int id_idx = 1; /* The first entry is the counter value */
291
292         if (!(evsel->attr.read_format & PERF_FORMAT_ID) ||
293             read(fd, &read_data, sizeof(read_data)) == -1)
294                 return -1;
295
296         if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_ENABLED)
297                 ++id_idx;
298         if (evsel->attr.read_format & PERF_FORMAT_TOTAL_TIME_RUNNING)
299                 ++id_idx;
300
301         perf_evlist__id_add(evlist, evsel, cpu, thread, read_data[id_idx]);
302         return 0;
303 }
304
305 struct perf_evsel *perf_evlist__id2evsel(struct perf_evlist *evlist, u64 id)
306 {
307         struct hlist_head *head;
308         struct hlist_node *pos;
309         struct perf_sample_id *sid;
310         int hash;
311
312         if (evlist->nr_entries == 1)
313                 return perf_evlist__first(evlist);
314
315         hash = hash_64(id, PERF_EVLIST__HLIST_BITS);
316         head = &evlist->heads[hash];
317
318         hlist_for_each_entry(sid, pos, head, node)
319                 if (sid->id == id)
320                         return sid->evsel;
321
322         if (!perf_evlist__sample_id_all(evlist))
323                 return perf_evlist__first(evlist);
324
325         return NULL;
326 }
327
328 union perf_event *perf_evlist__mmap_read(struct perf_evlist *evlist, int idx)
329 {
330         struct perf_mmap *md = &evlist->mmap[idx];
331         unsigned int head = perf_mmap__read_head(md);
332         unsigned int old = md->prev;
333         unsigned char *data = md->base + page_size;
334         union perf_event *event = NULL;
335
336         if (evlist->overwrite) {
337                 /*
338                  * If we're further behind than half the buffer, there's a chance
339                  * the writer will bite our tail and mess up the samples under us.
340                  *
341                  * If we somehow ended up ahead of the head, we got messed up.
342                  *
343                  * In either case, truncate and restart at head.
344                  */
345                 int diff = head - old;
346                 if (diff > md->mask / 2 || diff < 0) {
347                         fprintf(stderr, "WARNING: failed to keep up with mmap data.\n");
348
349                         /*
350                          * head points to a known good entry, start there.
351                          */
352                         old = head;
353                 }
354         }
355
356         if (old != head) {
357                 size_t size;
358
359                 event = (union perf_event *)&data[old & md->mask];
360                 size = event->header.size;
361
362                 /*
363                  * Event straddles the mmap boundary -- header should always
364                  * be inside due to u64 alignment of output.
365                  */
366                 if ((old & md->mask) + size != ((old + size) & md->mask)) {
367                         unsigned int offset = old;
368                         unsigned int len = min(sizeof(*event), size), cpy;
369                         void *dst = &evlist->event_copy;
370
371                         do {
372                                 cpy = min(md->mask + 1 - (offset & md->mask), len);
373                                 memcpy(dst, &data[offset & md->mask], cpy);
374                                 offset += cpy;
375                                 dst += cpy;
376                                 len -= cpy;
377                         } while (len);
378
379                         event = &evlist->event_copy;
380                 }
381
382                 old += size;
383         }
384
385         md->prev = old;
386
387         if (!evlist->overwrite)
388                 perf_mmap__write_tail(md, old);
389
390         return event;
391 }
392
393 void perf_evlist__munmap(struct perf_evlist *evlist)
394 {
395         int i;
396
397         for (i = 0; i < evlist->nr_mmaps; i++) {
398                 if (evlist->mmap[i].base != NULL) {
399                         munmap(evlist->mmap[i].base, evlist->mmap_len);
400                         evlist->mmap[i].base = NULL;
401                 }
402         }
403
404         free(evlist->mmap);
405         evlist->mmap = NULL;
406 }
407
408 static int perf_evlist__alloc_mmap(struct perf_evlist *evlist)
409 {
410         evlist->nr_mmaps = cpu_map__nr(evlist->cpus);
411         if (cpu_map__all(evlist->cpus))
412                 evlist->nr_mmaps = evlist->threads->nr;
413         evlist->mmap = zalloc(evlist->nr_mmaps * sizeof(struct perf_mmap));
414         return evlist->mmap != NULL ? 0 : -ENOMEM;
415 }
416
417 static int __perf_evlist__mmap(struct perf_evlist *evlist,
418                                int idx, int prot, int mask, int fd)
419 {
420         evlist->mmap[idx].prev = 0;
421         evlist->mmap[idx].mask = mask;
422         evlist->mmap[idx].base = mmap(NULL, evlist->mmap_len, prot,
423                                       MAP_SHARED, fd, 0);
424         if (evlist->mmap[idx].base == MAP_FAILED) {
425                 evlist->mmap[idx].base = NULL;
426                 return -1;
427         }
428
429         perf_evlist__add_pollfd(evlist, fd);
430         return 0;
431 }
432
433 static int perf_evlist__mmap_per_cpu(struct perf_evlist *evlist, int prot, int mask)
434 {
435         struct perf_evsel *evsel;
436         int cpu, thread;
437
438         for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
439                 int output = -1;
440
441                 for (thread = 0; thread < evlist->threads->nr; thread++) {
442                         list_for_each_entry(evsel, &evlist->entries, node) {
443                                 int fd = FD(evsel, cpu, thread);
444
445                                 if (output == -1) {
446                                         output = fd;
447                                         if (__perf_evlist__mmap(evlist, cpu,
448                                                                 prot, mask, output) < 0)
449                                                 goto out_unmap;
450                                 } else {
451                                         if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, output) != 0)
452                                                 goto out_unmap;
453                                 }
454
455                                 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
456                                     perf_evlist__id_add_fd(evlist, evsel, cpu, thread, fd) < 0)
457                                         goto out_unmap;
458                         }
459                 }
460         }
461
462         return 0;
463
464 out_unmap:
465         for (cpu = 0; cpu < evlist->cpus->nr; cpu++) {
466                 if (evlist->mmap[cpu].base != NULL) {
467                         munmap(evlist->mmap[cpu].base, evlist->mmap_len);
468                         evlist->mmap[cpu].base = NULL;
469                 }
470         }
471         return -1;
472 }
473
474 static int perf_evlist__mmap_per_thread(struct perf_evlist *evlist, int prot, int mask)
475 {
476         struct perf_evsel *evsel;
477         int thread;
478
479         for (thread = 0; thread < evlist->threads->nr; thread++) {
480                 int output = -1;
481
482                 list_for_each_entry(evsel, &evlist->entries, node) {
483                         int fd = FD(evsel, 0, thread);
484
485                         if (output == -1) {
486                                 output = fd;
487                                 if (__perf_evlist__mmap(evlist, thread,
488                                                         prot, mask, output) < 0)
489                                         goto out_unmap;
490                         } else {
491                                 if (ioctl(fd, PERF_EVENT_IOC_SET_OUTPUT, output) != 0)
492                                         goto out_unmap;
493                         }
494
495                         if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
496                             perf_evlist__id_add_fd(evlist, evsel, 0, thread, fd) < 0)
497                                 goto out_unmap;
498                 }
499         }
500
501         return 0;
502
503 out_unmap:
504         for (thread = 0; thread < evlist->threads->nr; thread++) {
505                 if (evlist->mmap[thread].base != NULL) {
506                         munmap(evlist->mmap[thread].base, evlist->mmap_len);
507                         evlist->mmap[thread].base = NULL;
508                 }
509         }
510         return -1;
511 }
512
513 /** perf_evlist__mmap - Create per cpu maps to receive events
514  *
515  * @evlist - list of events
516  * @pages - map length in pages
517  * @overwrite - overwrite older events?
518  *
519  * If overwrite is false the user needs to signal event consuption using:
520  *
521  *      struct perf_mmap *m = &evlist->mmap[cpu];
522  *      unsigned int head = perf_mmap__read_head(m);
523  *
524  *      perf_mmap__write_tail(m, head)
525  *
526  * Using perf_evlist__read_on_cpu does this automatically.
527  */
528 int perf_evlist__mmap(struct perf_evlist *evlist, unsigned int pages,
529                       bool overwrite)
530 {
531         struct perf_evsel *evsel;
532         const struct cpu_map *cpus = evlist->cpus;
533         const struct thread_map *threads = evlist->threads;
534         int prot = PROT_READ | (overwrite ? 0 : PROT_WRITE), mask;
535
536         /* 512 kiB: default amount of unprivileged mlocked memory */
537         if (pages == UINT_MAX)
538                 pages = (512 * 1024) / page_size;
539         else if (!is_power_of_2(pages))
540                 return -EINVAL;
541
542         mask = pages * page_size - 1;
543
544         if (evlist->mmap == NULL && perf_evlist__alloc_mmap(evlist) < 0)
545                 return -ENOMEM;
546
547         if (evlist->pollfd == NULL && perf_evlist__alloc_pollfd(evlist) < 0)
548                 return -ENOMEM;
549
550         evlist->overwrite = overwrite;
551         evlist->mmap_len = (pages + 1) * page_size;
552
553         list_for_each_entry(evsel, &evlist->entries, node) {
554                 if ((evsel->attr.read_format & PERF_FORMAT_ID) &&
555                     evsel->sample_id == NULL &&
556                     perf_evsel__alloc_id(evsel, cpu_map__nr(cpus), threads->nr) < 0)
557                         return -ENOMEM;
558         }
559
560         if (cpu_map__all(cpus))
561                 return perf_evlist__mmap_per_thread(evlist, prot, mask);
562
563         return perf_evlist__mmap_per_cpu(evlist, prot, mask);
564 }
565
566 int perf_evlist__create_maps(struct perf_evlist *evlist,
567                              struct perf_target *target)
568 {
569         evlist->threads = thread_map__new_str(target->pid, target->tid,
570                                               target->uid);
571
572         if (evlist->threads == NULL)
573                 return -1;
574
575         if (perf_target__has_task(target))
576                 evlist->cpus = cpu_map__dummy_new();
577         else if (!perf_target__has_cpu(target) && !target->uses_mmap)
578                 evlist->cpus = cpu_map__dummy_new();
579         else
580                 evlist->cpus = cpu_map__new(target->cpu_list);
581
582         if (evlist->cpus == NULL)
583                 goto out_delete_threads;
584
585         return 0;
586
587 out_delete_threads:
588         thread_map__delete(evlist->threads);
589         return -1;
590 }
591
592 void perf_evlist__delete_maps(struct perf_evlist *evlist)
593 {
594         cpu_map__delete(evlist->cpus);
595         thread_map__delete(evlist->threads);
596         evlist->cpus    = NULL;
597         evlist->threads = NULL;
598 }
599
600 int perf_evlist__apply_filters(struct perf_evlist *evlist)
601 {
602         struct perf_evsel *evsel;
603         int err = 0;
604         const int ncpus = cpu_map__nr(evlist->cpus),
605                   nthreads = evlist->threads->nr;
606
607         list_for_each_entry(evsel, &evlist->entries, node) {
608                 if (evsel->filter == NULL)
609                         continue;
610
611                 err = perf_evsel__set_filter(evsel, ncpus, nthreads, evsel->filter);
612                 if (err)
613                         break;
614         }
615
616         return err;
617 }
618
619 int perf_evlist__set_filter(struct perf_evlist *evlist, const char *filter)
620 {
621         struct perf_evsel *evsel;
622         int err = 0;
623         const int ncpus = cpu_map__nr(evlist->cpus),
624                   nthreads = evlist->threads->nr;
625
626         list_for_each_entry(evsel, &evlist->entries, node) {
627                 err = perf_evsel__set_filter(evsel, ncpus, nthreads, filter);
628                 if (err)
629                         break;
630         }
631
632         return err;
633 }
634
635 bool perf_evlist__valid_sample_type(struct perf_evlist *evlist)
636 {
637         struct perf_evsel *first = perf_evlist__first(evlist), *pos = first;
638
639         list_for_each_entry_continue(pos, &evlist->entries, node) {
640                 if (first->attr.sample_type != pos->attr.sample_type)
641                         return false;
642         }
643
644         return true;
645 }
646
647 u64 perf_evlist__sample_type(struct perf_evlist *evlist)
648 {
649         struct perf_evsel *first = perf_evlist__first(evlist);
650         return first->attr.sample_type;
651 }
652
653 u16 perf_evlist__id_hdr_size(struct perf_evlist *evlist)
654 {
655         struct perf_evsel *first = perf_evlist__first(evlist);
656         struct perf_sample *data;
657         u64 sample_type;
658         u16 size = 0;
659
660         if (!first->attr.sample_id_all)
661                 goto out;
662
663         sample_type = first->attr.sample_type;
664
665         if (sample_type & PERF_SAMPLE_TID)
666                 size += sizeof(data->tid) * 2;
667
668        if (sample_type & PERF_SAMPLE_TIME)
669                 size += sizeof(data->time);
670
671         if (sample_type & PERF_SAMPLE_ID)
672                 size += sizeof(data->id);
673
674         if (sample_type & PERF_SAMPLE_STREAM_ID)
675                 size += sizeof(data->stream_id);
676
677         if (sample_type & PERF_SAMPLE_CPU)
678                 size += sizeof(data->cpu) * 2;
679 out:
680         return size;
681 }
682
683 bool perf_evlist__valid_sample_id_all(struct perf_evlist *evlist)
684 {
685         struct perf_evsel *first = perf_evlist__first(evlist), *pos = first;
686
687         list_for_each_entry_continue(pos, &evlist->entries, node) {
688                 if (first->attr.sample_id_all != pos->attr.sample_id_all)
689                         return false;
690         }
691
692         return true;
693 }
694
695 bool perf_evlist__sample_id_all(struct perf_evlist *evlist)
696 {
697         struct perf_evsel *first = perf_evlist__first(evlist);
698         return first->attr.sample_id_all;
699 }
700
701 void perf_evlist__set_selected(struct perf_evlist *evlist,
702                                struct perf_evsel *evsel)
703 {
704         evlist->selected = evsel;
705 }
706
707 int perf_evlist__open(struct perf_evlist *evlist)
708 {
709         struct perf_evsel *evsel;
710         int err, ncpus, nthreads;
711
712         list_for_each_entry(evsel, &evlist->entries, node) {
713                 err = perf_evsel__open(evsel, evlist->cpus, evlist->threads);
714                 if (err < 0)
715                         goto out_err;
716         }
717
718         return 0;
719 out_err:
720         ncpus = evlist->cpus ? evlist->cpus->nr : 1;
721         nthreads = evlist->threads ? evlist->threads->nr : 1;
722
723         list_for_each_entry_reverse(evsel, &evlist->entries, node)
724                 perf_evsel__close(evsel, ncpus, nthreads);
725
726         errno = -err;
727         return err;
728 }
729
730 int perf_evlist__prepare_workload(struct perf_evlist *evlist,
731                                   struct perf_record_opts *opts,
732                                   const char *argv[])
733 {
734         int child_ready_pipe[2], go_pipe[2];
735         char bf;
736
737         if (pipe(child_ready_pipe) < 0) {
738                 perror("failed to create 'ready' pipe");
739                 return -1;
740         }
741
742         if (pipe(go_pipe) < 0) {
743                 perror("failed to create 'go' pipe");
744                 goto out_close_ready_pipe;
745         }
746
747         evlist->workload.pid = fork();
748         if (evlist->workload.pid < 0) {
749                 perror("failed to fork");
750                 goto out_close_pipes;
751         }
752
753         if (!evlist->workload.pid) {
754                 if (opts->pipe_output)
755                         dup2(2, 1);
756
757                 close(child_ready_pipe[0]);
758                 close(go_pipe[1]);
759                 fcntl(go_pipe[0], F_SETFD, FD_CLOEXEC);
760
761                 /*
762                  * Do a dummy execvp to get the PLT entry resolved,
763                  * so we avoid the resolver overhead on the real
764                  * execvp call.
765                  */
766                 execvp("", (char **)argv);
767
768                 /*
769                  * Tell the parent we're ready to go
770                  */
771                 close(child_ready_pipe[1]);
772
773                 /*
774                  * Wait until the parent tells us to go.
775                  */
776                 if (read(go_pipe[0], &bf, 1) == -1)
777                         perror("unable to read pipe");
778
779                 execvp(argv[0], (char **)argv);
780
781                 perror(argv[0]);
782                 kill(getppid(), SIGUSR1);
783                 exit(-1);
784         }
785
786         if (perf_target__none(&opts->target))
787                 evlist->threads->map[0] = evlist->workload.pid;
788
789         close(child_ready_pipe[1]);
790         close(go_pipe[0]);
791         /*
792          * wait for child to settle
793          */
794         if (read(child_ready_pipe[0], &bf, 1) == -1) {
795                 perror("unable to read pipe");
796                 goto out_close_pipes;
797         }
798
799         evlist->workload.cork_fd = go_pipe[1];
800         close(child_ready_pipe[0]);
801         return 0;
802
803 out_close_pipes:
804         close(go_pipe[0]);
805         close(go_pipe[1]);
806 out_close_ready_pipe:
807         close(child_ready_pipe[0]);
808         close(child_ready_pipe[1]);
809         return -1;
810 }
811
812 int perf_evlist__start_workload(struct perf_evlist *evlist)
813 {
814         if (evlist->workload.cork_fd > 0) {
815                 /*
816                  * Remove the cork, let it rip!
817                  */
818                 return close(evlist->workload.cork_fd);
819         }
820
821         return 0;
822 }
823
824 int perf_evlist__parse_sample(struct perf_evlist *evlist, union perf_event *event,
825                               struct perf_sample *sample)
826 {
827         struct perf_evsel *evsel = perf_evlist__first(evlist);
828         return perf_evsel__parse_sample(evsel, event, sample);
829 }
830
831 size_t perf_evlist__fprintf(struct perf_evlist *evlist, FILE *fp)
832 {
833         struct perf_evsel *evsel;
834         size_t printed = 0;
835
836         list_for_each_entry(evsel, &evlist->entries, node) {
837                 printed += fprintf(fp, "%s%s", evsel->idx ? ", " : "",
838                                    perf_evsel__name(evsel));
839         }
840
841         return printed + fprintf(fp, "\n");;
842 }