perf stat: Introduce --repeat forever
[linux-3.10.git] / tools / perf / util / evsel.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
10 #include <byteswap.h>
11 #include <linux/bitops.h>
12 #include "asm/bug.h"
13 #include <lk/debugfs.h>
14 #include "event-parse.h"
15 #include "evsel.h"
16 #include "evlist.h"
17 #include "util.h"
18 #include "cpumap.h"
19 #include "thread_map.h"
20 #include "target.h"
21 #include <linux/hw_breakpoint.h>
22 #include <linux/perf_event.h>
23 #include "perf_regs.h"
24
25 static struct {
26         bool sample_id_all;
27         bool exclude_guest;
28 } perf_missing_features;
29
30 #define FD(e, x, y) (*(int *)xyarray__entry(e->fd, x, y))
31
32 static int __perf_evsel__sample_size(u64 sample_type)
33 {
34         u64 mask = sample_type & PERF_SAMPLE_MASK;
35         int size = 0;
36         int i;
37
38         for (i = 0; i < 64; i++) {
39                 if (mask & (1ULL << i))
40                         size++;
41         }
42
43         size *= sizeof(u64);
44
45         return size;
46 }
47
48 void hists__init(struct hists *hists)
49 {
50         memset(hists, 0, sizeof(*hists));
51         hists->entries_in_array[0] = hists->entries_in_array[1] = RB_ROOT;
52         hists->entries_in = &hists->entries_in_array[0];
53         hists->entries_collapsed = RB_ROOT;
54         hists->entries = RB_ROOT;
55         pthread_mutex_init(&hists->lock, NULL);
56 }
57
58 void __perf_evsel__set_sample_bit(struct perf_evsel *evsel,
59                                   enum perf_event_sample_format bit)
60 {
61         if (!(evsel->attr.sample_type & bit)) {
62                 evsel->attr.sample_type |= bit;
63                 evsel->sample_size += sizeof(u64);
64         }
65 }
66
67 void __perf_evsel__reset_sample_bit(struct perf_evsel *evsel,
68                                     enum perf_event_sample_format bit)
69 {
70         if (evsel->attr.sample_type & bit) {
71                 evsel->attr.sample_type &= ~bit;
72                 evsel->sample_size -= sizeof(u64);
73         }
74 }
75
76 void perf_evsel__set_sample_id(struct perf_evsel *evsel)
77 {
78         perf_evsel__set_sample_bit(evsel, ID);
79         evsel->attr.read_format |= PERF_FORMAT_ID;
80 }
81
82 void perf_evsel__init(struct perf_evsel *evsel,
83                       struct perf_event_attr *attr, int idx)
84 {
85         evsel->idx         = idx;
86         evsel->attr        = *attr;
87         evsel->leader      = evsel;
88         INIT_LIST_HEAD(&evsel->node);
89         hists__init(&evsel->hists);
90         evsel->sample_size = __perf_evsel__sample_size(attr->sample_type);
91 }
92
93 struct perf_evsel *perf_evsel__new(struct perf_event_attr *attr, int idx)
94 {
95         struct perf_evsel *evsel = zalloc(sizeof(*evsel));
96
97         if (evsel != NULL)
98                 perf_evsel__init(evsel, attr, idx);
99
100         return evsel;
101 }
102
103 struct event_format *event_format__new(const char *sys, const char *name)
104 {
105         int fd, n;
106         char *filename;
107         void *bf = NULL, *nbf;
108         size_t size = 0, alloc_size = 0;
109         struct event_format *format = NULL;
110
111         if (asprintf(&filename, "%s/%s/%s/format", tracing_events_path, sys, name) < 0)
112                 goto out;
113
114         fd = open(filename, O_RDONLY);
115         if (fd < 0)
116                 goto out_free_filename;
117
118         do {
119                 if (size == alloc_size) {
120                         alloc_size += BUFSIZ;
121                         nbf = realloc(bf, alloc_size);
122                         if (nbf == NULL)
123                                 goto out_free_bf;
124                         bf = nbf;
125                 }
126
127                 n = read(fd, bf + size, BUFSIZ);
128                 if (n < 0)
129                         goto out_free_bf;
130                 size += n;
131         } while (n > 0);
132
133         pevent_parse_format(&format, bf, size, sys);
134
135 out_free_bf:
136         free(bf);
137         close(fd);
138 out_free_filename:
139         free(filename);
140 out:
141         return format;
142 }
143
144 struct perf_evsel *perf_evsel__newtp(const char *sys, const char *name, int idx)
145 {
146         struct perf_evsel *evsel = zalloc(sizeof(*evsel));
147
148         if (evsel != NULL) {
149                 struct perf_event_attr attr = {
150                         .type          = PERF_TYPE_TRACEPOINT,
151                         .sample_type   = (PERF_SAMPLE_RAW | PERF_SAMPLE_TIME |
152                                           PERF_SAMPLE_CPU | PERF_SAMPLE_PERIOD),
153                 };
154
155                 if (asprintf(&evsel->name, "%s:%s", sys, name) < 0)
156                         goto out_free;
157
158                 evsel->tp_format = event_format__new(sys, name);
159                 if (evsel->tp_format == NULL)
160                         goto out_free;
161
162                 event_attr_init(&attr);
163                 attr.config = evsel->tp_format->id;
164                 attr.sample_period = 1;
165                 perf_evsel__init(evsel, &attr, idx);
166         }
167
168         return evsel;
169
170 out_free:
171         free(evsel->name);
172         free(evsel);
173         return NULL;
174 }
175
176 const char *perf_evsel__hw_names[PERF_COUNT_HW_MAX] = {
177         "cycles",
178         "instructions",
179         "cache-references",
180         "cache-misses",
181         "branches",
182         "branch-misses",
183         "bus-cycles",
184         "stalled-cycles-frontend",
185         "stalled-cycles-backend",
186         "ref-cycles",
187 };
188
189 static const char *__perf_evsel__hw_name(u64 config)
190 {
191         if (config < PERF_COUNT_HW_MAX && perf_evsel__hw_names[config])
192                 return perf_evsel__hw_names[config];
193
194         return "unknown-hardware";
195 }
196
197 static int perf_evsel__add_modifiers(struct perf_evsel *evsel, char *bf, size_t size)
198 {
199         int colon = 0, r = 0;
200         struct perf_event_attr *attr = &evsel->attr;
201         bool exclude_guest_default = false;
202
203 #define MOD_PRINT(context, mod) do {                                    \
204                 if (!attr->exclude_##context) {                         \
205                         if (!colon) colon = ++r;                        \
206                         r += scnprintf(bf + r, size - r, "%c", mod);    \
207                 } } while(0)
208
209         if (attr->exclude_kernel || attr->exclude_user || attr->exclude_hv) {
210                 MOD_PRINT(kernel, 'k');
211                 MOD_PRINT(user, 'u');
212                 MOD_PRINT(hv, 'h');
213                 exclude_guest_default = true;
214         }
215
216         if (attr->precise_ip) {
217                 if (!colon)
218                         colon = ++r;
219                 r += scnprintf(bf + r, size - r, "%.*s", attr->precise_ip, "ppp");
220                 exclude_guest_default = true;
221         }
222
223         if (attr->exclude_host || attr->exclude_guest == exclude_guest_default) {
224                 MOD_PRINT(host, 'H');
225                 MOD_PRINT(guest, 'G');
226         }
227 #undef MOD_PRINT
228         if (colon)
229                 bf[colon - 1] = ':';
230         return r;
231 }
232
233 static int perf_evsel__hw_name(struct perf_evsel *evsel, char *bf, size_t size)
234 {
235         int r = scnprintf(bf, size, "%s", __perf_evsel__hw_name(evsel->attr.config));
236         return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
237 }
238
239 const char *perf_evsel__sw_names[PERF_COUNT_SW_MAX] = {
240         "cpu-clock",
241         "task-clock",
242         "page-faults",
243         "context-switches",
244         "cpu-migrations",
245         "minor-faults",
246         "major-faults",
247         "alignment-faults",
248         "emulation-faults",
249 };
250
251 static const char *__perf_evsel__sw_name(u64 config)
252 {
253         if (config < PERF_COUNT_SW_MAX && perf_evsel__sw_names[config])
254                 return perf_evsel__sw_names[config];
255         return "unknown-software";
256 }
257
258 static int perf_evsel__sw_name(struct perf_evsel *evsel, char *bf, size_t size)
259 {
260         int r = scnprintf(bf, size, "%s", __perf_evsel__sw_name(evsel->attr.config));
261         return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
262 }
263
264 static int __perf_evsel__bp_name(char *bf, size_t size, u64 addr, u64 type)
265 {
266         int r;
267
268         r = scnprintf(bf, size, "mem:0x%" PRIx64 ":", addr);
269
270         if (type & HW_BREAKPOINT_R)
271                 r += scnprintf(bf + r, size - r, "r");
272
273         if (type & HW_BREAKPOINT_W)
274                 r += scnprintf(bf + r, size - r, "w");
275
276         if (type & HW_BREAKPOINT_X)
277                 r += scnprintf(bf + r, size - r, "x");
278
279         return r;
280 }
281
282 static int perf_evsel__bp_name(struct perf_evsel *evsel, char *bf, size_t size)
283 {
284         struct perf_event_attr *attr = &evsel->attr;
285         int r = __perf_evsel__bp_name(bf, size, attr->bp_addr, attr->bp_type);
286         return r + perf_evsel__add_modifiers(evsel, bf + r, size - r);
287 }
288
289 const char *perf_evsel__hw_cache[PERF_COUNT_HW_CACHE_MAX]
290                                 [PERF_EVSEL__MAX_ALIASES] = {
291  { "L1-dcache", "l1-d",         "l1d",          "L1-data",              },
292  { "L1-icache", "l1-i",         "l1i",          "L1-instruction",       },
293  { "LLC",       "L2",                                                   },
294  { "dTLB",      "d-tlb",        "Data-TLB",                             },
295  { "iTLB",      "i-tlb",        "Instruction-TLB",                      },
296  { "branch",    "branches",     "bpu",          "btb",          "bpc",  },
297  { "node",                                                              },
298 };
299
300 const char *perf_evsel__hw_cache_op[PERF_COUNT_HW_CACHE_OP_MAX]
301                                    [PERF_EVSEL__MAX_ALIASES] = {
302  { "load",      "loads",        "read",                                 },
303  { "store",     "stores",       "write",                                },
304  { "prefetch",  "prefetches",   "speculative-read", "speculative-load", },
305 };
306
307 const char *perf_evsel__hw_cache_result[PERF_COUNT_HW_CACHE_RESULT_MAX]
308                                        [PERF_EVSEL__MAX_ALIASES] = {
309  { "refs",      "Reference",    "ops",          "access",               },
310  { "misses",    "miss",                                                 },
311 };
312
313 #define C(x)            PERF_COUNT_HW_CACHE_##x
314 #define CACHE_READ      (1 << C(OP_READ))
315 #define CACHE_WRITE     (1 << C(OP_WRITE))
316 #define CACHE_PREFETCH  (1 << C(OP_PREFETCH))
317 #define COP(x)          (1 << x)
318
319 /*
320  * cache operartion stat
321  * L1I : Read and prefetch only
322  * ITLB and BPU : Read-only
323  */
324 static unsigned long perf_evsel__hw_cache_stat[C(MAX)] = {
325  [C(L1D)]       = (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
326  [C(L1I)]       = (CACHE_READ | CACHE_PREFETCH),
327  [C(LL)]        = (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
328  [C(DTLB)]      = (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
329  [C(ITLB)]      = (CACHE_READ),
330  [C(BPU)]       = (CACHE_READ),
331  [C(NODE)]      = (CACHE_READ | CACHE_WRITE | CACHE_PREFETCH),
332 };
333
334 bool perf_evsel__is_cache_op_valid(u8 type, u8 op)
335 {
336         if (perf_evsel__hw_cache_stat[type] & COP(op))
337                 return true;    /* valid */
338         else
339                 return false;   /* invalid */
340 }
341
342 int __perf_evsel__hw_cache_type_op_res_name(u8 type, u8 op, u8 result,
343                                             char *bf, size_t size)
344 {
345         if (result) {
346                 return scnprintf(bf, size, "%s-%s-%s", perf_evsel__hw_cache[type][0],
347                                  perf_evsel__hw_cache_op[op][0],
348                                  perf_evsel__hw_cache_result[result][0]);
349         }
350
351         return scnprintf(bf, size, "%s-%s", perf_evsel__hw_cache[type][0],
352                          perf_evsel__hw_cache_op[op][1]);
353 }
354
355 static int __perf_evsel__hw_cache_name(u64 config, char *bf, size_t size)
356 {
357         u8 op, result, type = (config >>  0) & 0xff;
358         const char *err = "unknown-ext-hardware-cache-type";
359
360         if (type > PERF_COUNT_HW_CACHE_MAX)
361                 goto out_err;
362
363         op = (config >>  8) & 0xff;
364         err = "unknown-ext-hardware-cache-op";
365         if (op > PERF_COUNT_HW_CACHE_OP_MAX)
366                 goto out_err;
367
368         result = (config >> 16) & 0xff;
369         err = "unknown-ext-hardware-cache-result";
370         if (result > PERF_COUNT_HW_CACHE_RESULT_MAX)
371                 goto out_err;
372
373         err = "invalid-cache";
374         if (!perf_evsel__is_cache_op_valid(type, op))
375                 goto out_err;
376
377         return __perf_evsel__hw_cache_type_op_res_name(type, op, result, bf, size);
378 out_err:
379         return scnprintf(bf, size, "%s", err);
380 }
381
382 static int perf_evsel__hw_cache_name(struct perf_evsel *evsel, char *bf, size_t size)
383 {
384         int ret = __perf_evsel__hw_cache_name(evsel->attr.config, bf, size);
385         return ret + perf_evsel__add_modifiers(evsel, bf + ret, size - ret);
386 }
387
388 static int perf_evsel__raw_name(struct perf_evsel *evsel, char *bf, size_t size)
389 {
390         int ret = scnprintf(bf, size, "raw 0x%" PRIx64, evsel->attr.config);
391         return ret + perf_evsel__add_modifiers(evsel, bf + ret, size - ret);
392 }
393
394 const char *perf_evsel__name(struct perf_evsel *evsel)
395 {
396         char bf[128];
397
398         if (evsel->name)
399                 return evsel->name;
400
401         switch (evsel->attr.type) {
402         case PERF_TYPE_RAW:
403                 perf_evsel__raw_name(evsel, bf, sizeof(bf));
404                 break;
405
406         case PERF_TYPE_HARDWARE:
407                 perf_evsel__hw_name(evsel, bf, sizeof(bf));
408                 break;
409
410         case PERF_TYPE_HW_CACHE:
411                 perf_evsel__hw_cache_name(evsel, bf, sizeof(bf));
412                 break;
413
414         case PERF_TYPE_SOFTWARE:
415                 perf_evsel__sw_name(evsel, bf, sizeof(bf));
416                 break;
417
418         case PERF_TYPE_TRACEPOINT:
419                 scnprintf(bf, sizeof(bf), "%s", "unknown tracepoint");
420                 break;
421
422         case PERF_TYPE_BREAKPOINT:
423                 perf_evsel__bp_name(evsel, bf, sizeof(bf));
424                 break;
425
426         default:
427                 scnprintf(bf, sizeof(bf), "unknown attr type: %d",
428                           evsel->attr.type);
429                 break;
430         }
431
432         evsel->name = strdup(bf);
433
434         return evsel->name ?: "unknown";
435 }
436
437 const char *perf_evsel__group_name(struct perf_evsel *evsel)
438 {
439         return evsel->group_name ?: "anon group";
440 }
441
442 int perf_evsel__group_desc(struct perf_evsel *evsel, char *buf, size_t size)
443 {
444         int ret;
445         struct perf_evsel *pos;
446         const char *group_name = perf_evsel__group_name(evsel);
447
448         ret = scnprintf(buf, size, "%s", group_name);
449
450         ret += scnprintf(buf + ret, size - ret, " { %s",
451                          perf_evsel__name(evsel));
452
453         for_each_group_member(pos, evsel)
454                 ret += scnprintf(buf + ret, size - ret, ", %s",
455                                  perf_evsel__name(pos));
456
457         ret += scnprintf(buf + ret, size - ret, " }");
458
459         return ret;
460 }
461
462 /*
463  * The enable_on_exec/disabled value strategy:
464  *
465  *  1) For any type of traced program:
466  *    - all independent events and group leaders are disabled
467  *    - all group members are enabled
468  *
469  *     Group members are ruled by group leaders. They need to
470  *     be enabled, because the group scheduling relies on that.
471  *
472  *  2) For traced programs executed by perf:
473  *     - all independent events and group leaders have
474  *       enable_on_exec set
475  *     - we don't specifically enable or disable any event during
476  *       the record command
477  *
478  *     Independent events and group leaders are initially disabled
479  *     and get enabled by exec. Group members are ruled by group
480  *     leaders as stated in 1).
481  *
482  *  3) For traced programs attached by perf (pid/tid):
483  *     - we specifically enable or disable all events during
484  *       the record command
485  *
486  *     When attaching events to already running traced we
487  *     enable/disable events specifically, as there's no
488  *     initial traced exec call.
489  */
490 void perf_evsel__config(struct perf_evsel *evsel,
491                         struct perf_record_opts *opts)
492 {
493         struct perf_event_attr *attr = &evsel->attr;
494         int track = !evsel->idx; /* only the first counter needs these */
495
496         attr->sample_id_all = perf_missing_features.sample_id_all ? 0 : 1;
497         attr->inherit       = !opts->no_inherit;
498
499         perf_evsel__set_sample_bit(evsel, IP);
500         perf_evsel__set_sample_bit(evsel, TID);
501
502         /*
503          * We default some events to a 1 default interval. But keep
504          * it a weak assumption overridable by the user.
505          */
506         if (!attr->sample_period || (opts->user_freq != UINT_MAX &&
507                                      opts->user_interval != ULLONG_MAX)) {
508                 if (opts->freq) {
509                         perf_evsel__set_sample_bit(evsel, PERIOD);
510                         attr->freq              = 1;
511                         attr->sample_freq       = opts->freq;
512                 } else {
513                         attr->sample_period = opts->default_interval;
514                 }
515         }
516
517         if (opts->no_samples)
518                 attr->sample_freq = 0;
519
520         if (opts->inherit_stat)
521                 attr->inherit_stat = 1;
522
523         if (opts->sample_address) {
524                 perf_evsel__set_sample_bit(evsel, ADDR);
525                 attr->mmap_data = track;
526         }
527
528         if (opts->call_graph) {
529                 perf_evsel__set_sample_bit(evsel, CALLCHAIN);
530
531                 if (opts->call_graph == CALLCHAIN_DWARF) {
532                         perf_evsel__set_sample_bit(evsel, REGS_USER);
533                         perf_evsel__set_sample_bit(evsel, STACK_USER);
534                         attr->sample_regs_user = PERF_REGS_MASK;
535                         attr->sample_stack_user = opts->stack_dump_size;
536                         attr->exclude_callchain_user = 1;
537                 }
538         }
539
540         if (perf_target__has_cpu(&opts->target))
541                 perf_evsel__set_sample_bit(evsel, CPU);
542
543         if (opts->period)
544                 perf_evsel__set_sample_bit(evsel, PERIOD);
545
546         if (!perf_missing_features.sample_id_all &&
547             (opts->sample_time || !opts->no_inherit ||
548              perf_target__has_cpu(&opts->target)))
549                 perf_evsel__set_sample_bit(evsel, TIME);
550
551         if (opts->raw_samples) {
552                 perf_evsel__set_sample_bit(evsel, TIME);
553                 perf_evsel__set_sample_bit(evsel, RAW);
554                 perf_evsel__set_sample_bit(evsel, CPU);
555         }
556
557         if (opts->no_delay) {
558                 attr->watermark = 0;
559                 attr->wakeup_events = 1;
560         }
561         if (opts->branch_stack) {
562                 perf_evsel__set_sample_bit(evsel, BRANCH_STACK);
563                 attr->branch_sample_type = opts->branch_stack;
564         }
565
566         attr->mmap = track;
567         attr->comm = track;
568
569         /*
570          * XXX see the function comment above
571          *
572          * Disabling only independent events or group leaders,
573          * keeping group members enabled.
574          */
575         if (perf_evsel__is_group_leader(evsel))
576                 attr->disabled = 1;
577
578         /*
579          * Setting enable_on_exec for independent events and
580          * group leaders for traced executed by perf.
581          */
582         if (perf_target__none(&opts->target) && perf_evsel__is_group_leader(evsel))
583                 attr->enable_on_exec = 1;
584 }
585
586 int perf_evsel__alloc_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
587 {
588         int cpu, thread;
589         evsel->fd = xyarray__new(ncpus, nthreads, sizeof(int));
590
591         if (evsel->fd) {
592                 for (cpu = 0; cpu < ncpus; cpu++) {
593                         for (thread = 0; thread < nthreads; thread++) {
594                                 FD(evsel, cpu, thread) = -1;
595                         }
596                 }
597         }
598
599         return evsel->fd != NULL ? 0 : -ENOMEM;
600 }
601
602 int perf_evsel__set_filter(struct perf_evsel *evsel, int ncpus, int nthreads,
603                            const char *filter)
604 {
605         int cpu, thread;
606
607         for (cpu = 0; cpu < ncpus; cpu++) {
608                 for (thread = 0; thread < nthreads; thread++) {
609                         int fd = FD(evsel, cpu, thread),
610                             err = ioctl(fd, PERF_EVENT_IOC_SET_FILTER, filter);
611
612                         if (err)
613                                 return err;
614                 }
615         }
616
617         return 0;
618 }
619
620 int perf_evsel__alloc_id(struct perf_evsel *evsel, int ncpus, int nthreads)
621 {
622         evsel->sample_id = xyarray__new(ncpus, nthreads, sizeof(struct perf_sample_id));
623         if (evsel->sample_id == NULL)
624                 return -ENOMEM;
625
626         evsel->id = zalloc(ncpus * nthreads * sizeof(u64));
627         if (evsel->id == NULL) {
628                 xyarray__delete(evsel->sample_id);
629                 evsel->sample_id = NULL;
630                 return -ENOMEM;
631         }
632
633         return 0;
634 }
635
636 void perf_evsel__reset_counts(struct perf_evsel *evsel, int ncpus)
637 {
638         memset(evsel->counts, 0, (sizeof(*evsel->counts) +
639                                  (ncpus * sizeof(struct perf_counts_values))));
640 }
641
642 int perf_evsel__alloc_counts(struct perf_evsel *evsel, int ncpus)
643 {
644         evsel->counts = zalloc((sizeof(*evsel->counts) +
645                                 (ncpus * sizeof(struct perf_counts_values))));
646         return evsel->counts != NULL ? 0 : -ENOMEM;
647 }
648
649 void perf_evsel__free_fd(struct perf_evsel *evsel)
650 {
651         xyarray__delete(evsel->fd);
652         evsel->fd = NULL;
653 }
654
655 void perf_evsel__free_id(struct perf_evsel *evsel)
656 {
657         xyarray__delete(evsel->sample_id);
658         evsel->sample_id = NULL;
659         free(evsel->id);
660         evsel->id = NULL;
661 }
662
663 void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
664 {
665         int cpu, thread;
666
667         for (cpu = 0; cpu < ncpus; cpu++)
668                 for (thread = 0; thread < nthreads; ++thread) {
669                         close(FD(evsel, cpu, thread));
670                         FD(evsel, cpu, thread) = -1;
671                 }
672 }
673
674 void perf_evsel__free_counts(struct perf_evsel *evsel)
675 {
676         free(evsel->counts);
677 }
678
679 void perf_evsel__exit(struct perf_evsel *evsel)
680 {
681         assert(list_empty(&evsel->node));
682         perf_evsel__free_fd(evsel);
683         perf_evsel__free_id(evsel);
684 }
685
686 void perf_evsel__delete(struct perf_evsel *evsel)
687 {
688         perf_evsel__exit(evsel);
689         close_cgroup(evsel->cgrp);
690         free(evsel->group_name);
691         if (evsel->tp_format)
692                 pevent_free_format(evsel->tp_format);
693         free(evsel->name);
694         free(evsel);
695 }
696
697 static inline void compute_deltas(struct perf_evsel *evsel,
698                                   int cpu,
699                                   struct perf_counts_values *count)
700 {
701         struct perf_counts_values tmp;
702
703         if (!evsel->prev_raw_counts)
704                 return;
705
706         if (cpu == -1) {
707                 tmp = evsel->prev_raw_counts->aggr;
708                 evsel->prev_raw_counts->aggr = *count;
709         } else {
710                 tmp = evsel->prev_raw_counts->cpu[cpu];
711                 evsel->prev_raw_counts->cpu[cpu] = *count;
712         }
713
714         count->val = count->val - tmp.val;
715         count->ena = count->ena - tmp.ena;
716         count->run = count->run - tmp.run;
717 }
718
719 int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
720                               int cpu, int thread, bool scale)
721 {
722         struct perf_counts_values count;
723         size_t nv = scale ? 3 : 1;
724
725         if (FD(evsel, cpu, thread) < 0)
726                 return -EINVAL;
727
728         if (evsel->counts == NULL && perf_evsel__alloc_counts(evsel, cpu + 1) < 0)
729                 return -ENOMEM;
730
731         if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) < 0)
732                 return -errno;
733
734         compute_deltas(evsel, cpu, &count);
735
736         if (scale) {
737                 if (count.run == 0)
738                         count.val = 0;
739                 else if (count.run < count.ena)
740                         count.val = (u64)((double)count.val * count.ena / count.run + 0.5);
741         } else
742                 count.ena = count.run = 0;
743
744         evsel->counts->cpu[cpu] = count;
745         return 0;
746 }
747
748 int __perf_evsel__read(struct perf_evsel *evsel,
749                        int ncpus, int nthreads, bool scale)
750 {
751         size_t nv = scale ? 3 : 1;
752         int cpu, thread;
753         struct perf_counts_values *aggr = &evsel->counts->aggr, count;
754
755         aggr->val = aggr->ena = aggr->run = 0;
756
757         for (cpu = 0; cpu < ncpus; cpu++) {
758                 for (thread = 0; thread < nthreads; thread++) {
759                         if (FD(evsel, cpu, thread) < 0)
760                                 continue;
761
762                         if (readn(FD(evsel, cpu, thread),
763                                   &count, nv * sizeof(u64)) < 0)
764                                 return -errno;
765
766                         aggr->val += count.val;
767                         if (scale) {
768                                 aggr->ena += count.ena;
769                                 aggr->run += count.run;
770                         }
771                 }
772         }
773
774         compute_deltas(evsel, -1, aggr);
775
776         evsel->counts->scaled = 0;
777         if (scale) {
778                 if (aggr->run == 0) {
779                         evsel->counts->scaled = -1;
780                         aggr->val = 0;
781                         return 0;
782                 }
783
784                 if (aggr->run < aggr->ena) {
785                         evsel->counts->scaled = 1;
786                         aggr->val = (u64)((double)aggr->val * aggr->ena / aggr->run + 0.5);
787                 }
788         } else
789                 aggr->ena = aggr->run = 0;
790
791         return 0;
792 }
793
794 static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread)
795 {
796         struct perf_evsel *leader = evsel->leader;
797         int fd;
798
799         if (perf_evsel__is_group_leader(evsel))
800                 return -1;
801
802         /*
803          * Leader must be already processed/open,
804          * if not it's a bug.
805          */
806         BUG_ON(!leader->fd);
807
808         fd = FD(leader, cpu, thread);
809         BUG_ON(fd == -1);
810
811         return fd;
812 }
813
814 static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
815                               struct thread_map *threads)
816 {
817         int cpu, thread;
818         unsigned long flags = 0;
819         int pid = -1, err;
820
821         if (evsel->fd == NULL &&
822             perf_evsel__alloc_fd(evsel, cpus->nr, threads->nr) < 0)
823                 return -ENOMEM;
824
825         if (evsel->cgrp) {
826                 flags = PERF_FLAG_PID_CGROUP;
827                 pid = evsel->cgrp->fd;
828         }
829
830 fallback_missing_features:
831         if (perf_missing_features.exclude_guest)
832                 evsel->attr.exclude_guest = evsel->attr.exclude_host = 0;
833 retry_sample_id:
834         if (perf_missing_features.sample_id_all)
835                 evsel->attr.sample_id_all = 0;
836
837         for (cpu = 0; cpu < cpus->nr; cpu++) {
838
839                 for (thread = 0; thread < threads->nr; thread++) {
840                         int group_fd;
841
842                         if (!evsel->cgrp)
843                                 pid = threads->map[thread];
844
845                         group_fd = get_group_fd(evsel, cpu, thread);
846
847                         FD(evsel, cpu, thread) = sys_perf_event_open(&evsel->attr,
848                                                                      pid,
849                                                                      cpus->map[cpu],
850                                                                      group_fd, flags);
851                         if (FD(evsel, cpu, thread) < 0) {
852                                 err = -errno;
853                                 goto try_fallback;
854                         }
855                 }
856         }
857
858         return 0;
859
860 try_fallback:
861         if (err != -EINVAL || cpu > 0 || thread > 0)
862                 goto out_close;
863
864         if (!perf_missing_features.exclude_guest &&
865             (evsel->attr.exclude_guest || evsel->attr.exclude_host)) {
866                 perf_missing_features.exclude_guest = true;
867                 goto fallback_missing_features;
868         } else if (!perf_missing_features.sample_id_all) {
869                 perf_missing_features.sample_id_all = true;
870                 goto retry_sample_id;
871         }
872
873 out_close:
874         do {
875                 while (--thread >= 0) {
876                         close(FD(evsel, cpu, thread));
877                         FD(evsel, cpu, thread) = -1;
878                 }
879                 thread = threads->nr;
880         } while (--cpu >= 0);
881         return err;
882 }
883
884 void perf_evsel__close(struct perf_evsel *evsel, int ncpus, int nthreads)
885 {
886         if (evsel->fd == NULL)
887                 return;
888
889         perf_evsel__close_fd(evsel, ncpus, nthreads);
890         perf_evsel__free_fd(evsel);
891         evsel->fd = NULL;
892 }
893
894 static struct {
895         struct cpu_map map;
896         int cpus[1];
897 } empty_cpu_map = {
898         .map.nr = 1,
899         .cpus   = { -1, },
900 };
901
902 static struct {
903         struct thread_map map;
904         int threads[1];
905 } empty_thread_map = {
906         .map.nr  = 1,
907         .threads = { -1, },
908 };
909
910 int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
911                      struct thread_map *threads)
912 {
913         if (cpus == NULL) {
914                 /* Work around old compiler warnings about strict aliasing */
915                 cpus = &empty_cpu_map.map;
916         }
917
918         if (threads == NULL)
919                 threads = &empty_thread_map.map;
920
921         return __perf_evsel__open(evsel, cpus, threads);
922 }
923
924 int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
925                              struct cpu_map *cpus)
926 {
927         return __perf_evsel__open(evsel, cpus, &empty_thread_map.map);
928 }
929
930 int perf_evsel__open_per_thread(struct perf_evsel *evsel,
931                                 struct thread_map *threads)
932 {
933         return __perf_evsel__open(evsel, &empty_cpu_map.map, threads);
934 }
935
936 static int perf_evsel__parse_id_sample(const struct perf_evsel *evsel,
937                                        const union perf_event *event,
938                                        struct perf_sample *sample)
939 {
940         u64 type = evsel->attr.sample_type;
941         const u64 *array = event->sample.array;
942         bool swapped = evsel->needs_swap;
943         union u64_swap u;
944
945         array += ((event->header.size -
946                    sizeof(event->header)) / sizeof(u64)) - 1;
947
948         if (type & PERF_SAMPLE_CPU) {
949                 u.val64 = *array;
950                 if (swapped) {
951                         /* undo swap of u64, then swap on individual u32s */
952                         u.val64 = bswap_64(u.val64);
953                         u.val32[0] = bswap_32(u.val32[0]);
954                 }
955
956                 sample->cpu = u.val32[0];
957                 array--;
958         }
959
960         if (type & PERF_SAMPLE_STREAM_ID) {
961                 sample->stream_id = *array;
962                 array--;
963         }
964
965         if (type & PERF_SAMPLE_ID) {
966                 sample->id = *array;
967                 array--;
968         }
969
970         if (type & PERF_SAMPLE_TIME) {
971                 sample->time = *array;
972                 array--;
973         }
974
975         if (type & PERF_SAMPLE_TID) {
976                 u.val64 = *array;
977                 if (swapped) {
978                         /* undo swap of u64, then swap on individual u32s */
979                         u.val64 = bswap_64(u.val64);
980                         u.val32[0] = bswap_32(u.val32[0]);
981                         u.val32[1] = bswap_32(u.val32[1]);
982                 }
983
984                 sample->pid = u.val32[0];
985                 sample->tid = u.val32[1];
986         }
987
988         return 0;
989 }
990
991 static bool sample_overlap(const union perf_event *event,
992                            const void *offset, u64 size)
993 {
994         const void *base = event;
995
996         if (offset + size > base + event->header.size)
997                 return true;
998
999         return false;
1000 }
1001
1002 int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
1003                              struct perf_sample *data)
1004 {
1005         u64 type = evsel->attr.sample_type;
1006         u64 regs_user = evsel->attr.sample_regs_user;
1007         bool swapped = evsel->needs_swap;
1008         const u64 *array;
1009
1010         /*
1011          * used for cross-endian analysis. See git commit 65014ab3
1012          * for why this goofiness is needed.
1013          */
1014         union u64_swap u;
1015
1016         memset(data, 0, sizeof(*data));
1017         data->cpu = data->pid = data->tid = -1;
1018         data->stream_id = data->id = data->time = -1ULL;
1019         data->period = 1;
1020
1021         if (event->header.type != PERF_RECORD_SAMPLE) {
1022                 if (!evsel->attr.sample_id_all)
1023                         return 0;
1024                 return perf_evsel__parse_id_sample(evsel, event, data);
1025         }
1026
1027         array = event->sample.array;
1028
1029         if (evsel->sample_size + sizeof(event->header) > event->header.size)
1030                 return -EFAULT;
1031
1032         if (type & PERF_SAMPLE_IP) {
1033                 data->ip = event->ip.ip;
1034                 array++;
1035         }
1036
1037         if (type & PERF_SAMPLE_TID) {
1038                 u.val64 = *array;
1039                 if (swapped) {
1040                         /* undo swap of u64, then swap on individual u32s */
1041                         u.val64 = bswap_64(u.val64);
1042                         u.val32[0] = bswap_32(u.val32[0]);
1043                         u.val32[1] = bswap_32(u.val32[1]);
1044                 }
1045
1046                 data->pid = u.val32[0];
1047                 data->tid = u.val32[1];
1048                 array++;
1049         }
1050
1051         if (type & PERF_SAMPLE_TIME) {
1052                 data->time = *array;
1053                 array++;
1054         }
1055
1056         data->addr = 0;
1057         if (type & PERF_SAMPLE_ADDR) {
1058                 data->addr = *array;
1059                 array++;
1060         }
1061
1062         data->id = -1ULL;
1063         if (type & PERF_SAMPLE_ID) {
1064                 data->id = *array;
1065                 array++;
1066         }
1067
1068         if (type & PERF_SAMPLE_STREAM_ID) {
1069                 data->stream_id = *array;
1070                 array++;
1071         }
1072
1073         if (type & PERF_SAMPLE_CPU) {
1074
1075                 u.val64 = *array;
1076                 if (swapped) {
1077                         /* undo swap of u64, then swap on individual u32s */
1078                         u.val64 = bswap_64(u.val64);
1079                         u.val32[0] = bswap_32(u.val32[0]);
1080                 }
1081
1082                 data->cpu = u.val32[0];
1083                 array++;
1084         }
1085
1086         if (type & PERF_SAMPLE_PERIOD) {
1087                 data->period = *array;
1088                 array++;
1089         }
1090
1091         if (type & PERF_SAMPLE_READ) {
1092                 fprintf(stderr, "PERF_SAMPLE_READ is unsupported for now\n");
1093                 return -1;
1094         }
1095
1096         if (type & PERF_SAMPLE_CALLCHAIN) {
1097                 if (sample_overlap(event, array, sizeof(data->callchain->nr)))
1098                         return -EFAULT;
1099
1100                 data->callchain = (struct ip_callchain *)array;
1101
1102                 if (sample_overlap(event, array, data->callchain->nr))
1103                         return -EFAULT;
1104
1105                 array += 1 + data->callchain->nr;
1106         }
1107
1108         if (type & PERF_SAMPLE_RAW) {
1109                 const u64 *pdata;
1110
1111                 u.val64 = *array;
1112                 if (WARN_ONCE(swapped,
1113                               "Endianness of raw data not corrected!\n")) {
1114                         /* undo swap of u64, then swap on individual u32s */
1115                         u.val64 = bswap_64(u.val64);
1116                         u.val32[0] = bswap_32(u.val32[0]);
1117                         u.val32[1] = bswap_32(u.val32[1]);
1118                 }
1119
1120                 if (sample_overlap(event, array, sizeof(u32)))
1121                         return -EFAULT;
1122
1123                 data->raw_size = u.val32[0];
1124                 pdata = (void *) array + sizeof(u32);
1125
1126                 if (sample_overlap(event, pdata, data->raw_size))
1127                         return -EFAULT;
1128
1129                 data->raw_data = (void *) pdata;
1130
1131                 array = (void *)array + data->raw_size + sizeof(u32);
1132         }
1133
1134         if (type & PERF_SAMPLE_BRANCH_STACK) {
1135                 u64 sz;
1136
1137                 data->branch_stack = (struct branch_stack *)array;
1138                 array++; /* nr */
1139
1140                 sz = data->branch_stack->nr * sizeof(struct branch_entry);
1141                 sz /= sizeof(u64);
1142                 array += sz;
1143         }
1144
1145         if (type & PERF_SAMPLE_REGS_USER) {
1146                 /* First u64 tells us if we have any regs in sample. */
1147                 u64 avail = *array++;
1148
1149                 if (avail) {
1150                         data->user_regs.regs = (u64 *)array;
1151                         array += hweight_long(regs_user);
1152                 }
1153         }
1154
1155         if (type & PERF_SAMPLE_STACK_USER) {
1156                 u64 size = *array++;
1157
1158                 data->user_stack.offset = ((char *)(array - 1)
1159                                           - (char *) event);
1160
1161                 if (!size) {
1162                         data->user_stack.size = 0;
1163                 } else {
1164                         data->user_stack.data = (char *)array;
1165                         array += size / sizeof(*array);
1166                         data->user_stack.size = *array;
1167                 }
1168         }
1169
1170         return 0;
1171 }
1172
1173 int perf_event__synthesize_sample(union perf_event *event, u64 type,
1174                                   const struct perf_sample *sample,
1175                                   bool swapped)
1176 {
1177         u64 *array;
1178
1179         /*
1180          * used for cross-endian analysis. See git commit 65014ab3
1181          * for why this goofiness is needed.
1182          */
1183         union u64_swap u;
1184
1185         array = event->sample.array;
1186
1187         if (type & PERF_SAMPLE_IP) {
1188                 event->ip.ip = sample->ip;
1189                 array++;
1190         }
1191
1192         if (type & PERF_SAMPLE_TID) {
1193                 u.val32[0] = sample->pid;
1194                 u.val32[1] = sample->tid;
1195                 if (swapped) {
1196                         /*
1197                          * Inverse of what is done in perf_evsel__parse_sample
1198                          */
1199                         u.val32[0] = bswap_32(u.val32[0]);
1200                         u.val32[1] = bswap_32(u.val32[1]);
1201                         u.val64 = bswap_64(u.val64);
1202                 }
1203
1204                 *array = u.val64;
1205                 array++;
1206         }
1207
1208         if (type & PERF_SAMPLE_TIME) {
1209                 *array = sample->time;
1210                 array++;
1211         }
1212
1213         if (type & PERF_SAMPLE_ADDR) {
1214                 *array = sample->addr;
1215                 array++;
1216         }
1217
1218         if (type & PERF_SAMPLE_ID) {
1219                 *array = sample->id;
1220                 array++;
1221         }
1222
1223         if (type & PERF_SAMPLE_STREAM_ID) {
1224                 *array = sample->stream_id;
1225                 array++;
1226         }
1227
1228         if (type & PERF_SAMPLE_CPU) {
1229                 u.val32[0] = sample->cpu;
1230                 if (swapped) {
1231                         /*
1232                          * Inverse of what is done in perf_evsel__parse_sample
1233                          */
1234                         u.val32[0] = bswap_32(u.val32[0]);
1235                         u.val64 = bswap_64(u.val64);
1236                 }
1237                 *array = u.val64;
1238                 array++;
1239         }
1240
1241         if (type & PERF_SAMPLE_PERIOD) {
1242                 *array = sample->period;
1243                 array++;
1244         }
1245
1246         return 0;
1247 }
1248
1249 struct format_field *perf_evsel__field(struct perf_evsel *evsel, const char *name)
1250 {
1251         return pevent_find_field(evsel->tp_format, name);
1252 }
1253
1254 void *perf_evsel__rawptr(struct perf_evsel *evsel, struct perf_sample *sample,
1255                          const char *name)
1256 {
1257         struct format_field *field = perf_evsel__field(evsel, name);
1258         int offset;
1259
1260         if (!field)
1261                 return NULL;
1262
1263         offset = field->offset;
1264
1265         if (field->flags & FIELD_IS_DYNAMIC) {
1266                 offset = *(int *)(sample->raw_data + field->offset);
1267                 offset &= 0xffff;
1268         }
1269
1270         return sample->raw_data + offset;
1271 }
1272
1273 u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
1274                        const char *name)
1275 {
1276         struct format_field *field = perf_evsel__field(evsel, name);
1277         void *ptr;
1278         u64 value;
1279
1280         if (!field)
1281                 return 0;
1282
1283         ptr = sample->raw_data + field->offset;
1284
1285         switch (field->size) {
1286         case 1:
1287                 return *(u8 *)ptr;
1288         case 2:
1289                 value = *(u16 *)ptr;
1290                 break;
1291         case 4:
1292                 value = *(u32 *)ptr;
1293                 break;
1294         case 8:
1295                 value = *(u64 *)ptr;
1296                 break;
1297         default:
1298                 return 0;
1299         }
1300
1301         if (!evsel->needs_swap)
1302                 return value;
1303
1304         switch (field->size) {
1305         case 2:
1306                 return bswap_16(value);
1307         case 4:
1308                 return bswap_32(value);
1309         case 8:
1310                 return bswap_64(value);
1311         default:
1312                 return 0;
1313         }
1314
1315         return 0;
1316 }
1317
1318 static int comma_fprintf(FILE *fp, bool *first, const char *fmt, ...)
1319 {
1320         va_list args;
1321         int ret = 0;
1322
1323         if (!*first) {
1324                 ret += fprintf(fp, ",");
1325         } else {
1326                 ret += fprintf(fp, ":");
1327                 *first = false;
1328         }
1329
1330         va_start(args, fmt);
1331         ret += vfprintf(fp, fmt, args);
1332         va_end(args);
1333         return ret;
1334 }
1335
1336 static int __if_fprintf(FILE *fp, bool *first, const char *field, u64 value)
1337 {
1338         if (value == 0)
1339                 return 0;
1340
1341         return comma_fprintf(fp, first, " %s: %" PRIu64, field, value);
1342 }
1343
1344 #define if_print(field) printed += __if_fprintf(fp, &first, #field, evsel->attr.field)
1345
1346 struct bit_names {
1347         int bit;
1348         const char *name;
1349 };
1350
1351 static int bits__fprintf(FILE *fp, const char *field, u64 value,
1352                          struct bit_names *bits, bool *first)
1353 {
1354         int i = 0, printed = comma_fprintf(fp, first, " %s: ", field);
1355         bool first_bit = true;
1356
1357         do {
1358                 if (value & bits[i].bit) {
1359                         printed += fprintf(fp, "%s%s", first_bit ? "" : "|", bits[i].name);
1360                         first_bit = false;
1361                 }
1362         } while (bits[++i].name != NULL);
1363
1364         return printed;
1365 }
1366
1367 static int sample_type__fprintf(FILE *fp, bool *first, u64 value)
1368 {
1369 #define bit_name(n) { PERF_SAMPLE_##n, #n }
1370         struct bit_names bits[] = {
1371                 bit_name(IP), bit_name(TID), bit_name(TIME), bit_name(ADDR),
1372                 bit_name(READ), bit_name(CALLCHAIN), bit_name(ID), bit_name(CPU),
1373                 bit_name(PERIOD), bit_name(STREAM_ID), bit_name(RAW),
1374                 bit_name(BRANCH_STACK), bit_name(REGS_USER), bit_name(STACK_USER),
1375                 { .name = NULL, }
1376         };
1377 #undef bit_name
1378         return bits__fprintf(fp, "sample_type", value, bits, first);
1379 }
1380
1381 static int read_format__fprintf(FILE *fp, bool *first, u64 value)
1382 {
1383 #define bit_name(n) { PERF_FORMAT_##n, #n }
1384         struct bit_names bits[] = {
1385                 bit_name(TOTAL_TIME_ENABLED), bit_name(TOTAL_TIME_RUNNING),
1386                 bit_name(ID), bit_name(GROUP),
1387                 { .name = NULL, }
1388         };
1389 #undef bit_name
1390         return bits__fprintf(fp, "read_format", value, bits, first);
1391 }
1392
1393 int perf_evsel__fprintf(struct perf_evsel *evsel,
1394                         struct perf_attr_details *details, FILE *fp)
1395 {
1396         bool first = true;
1397         int printed = 0;
1398
1399         if (details->event_group) {
1400                 struct perf_evsel *pos;
1401
1402                 if (!perf_evsel__is_group_leader(evsel))
1403                         return 0;
1404
1405                 if (evsel->nr_members > 1)
1406                         printed += fprintf(fp, "%s{", evsel->group_name ?: "");
1407
1408                 printed += fprintf(fp, "%s", perf_evsel__name(evsel));
1409                 for_each_group_member(pos, evsel)
1410                         printed += fprintf(fp, ",%s", perf_evsel__name(pos));
1411
1412                 if (evsel->nr_members > 1)
1413                         printed += fprintf(fp, "}");
1414                 goto out;
1415         }
1416
1417         printed += fprintf(fp, "%s", perf_evsel__name(evsel));
1418
1419         if (details->verbose || details->freq) {
1420                 printed += comma_fprintf(fp, &first, " sample_freq=%" PRIu64,
1421                                          (u64)evsel->attr.sample_freq);
1422         }
1423
1424         if (details->verbose) {
1425                 if_print(type);
1426                 if_print(config);
1427                 if_print(config1);
1428                 if_print(config2);
1429                 if_print(size);
1430                 printed += sample_type__fprintf(fp, &first, evsel->attr.sample_type);
1431                 if (evsel->attr.read_format)
1432                         printed += read_format__fprintf(fp, &first, evsel->attr.read_format);
1433                 if_print(disabled);
1434                 if_print(inherit);
1435                 if_print(pinned);
1436                 if_print(exclusive);
1437                 if_print(exclude_user);
1438                 if_print(exclude_kernel);
1439                 if_print(exclude_hv);
1440                 if_print(exclude_idle);
1441                 if_print(mmap);
1442                 if_print(comm);
1443                 if_print(freq);
1444                 if_print(inherit_stat);
1445                 if_print(enable_on_exec);
1446                 if_print(task);
1447                 if_print(watermark);
1448                 if_print(precise_ip);
1449                 if_print(mmap_data);
1450                 if_print(sample_id_all);
1451                 if_print(exclude_host);
1452                 if_print(exclude_guest);
1453                 if_print(__reserved_1);
1454                 if_print(wakeup_events);
1455                 if_print(bp_type);
1456                 if_print(branch_sample_type);
1457         }
1458 out:
1459         fputc('\n', fp);
1460         return ++printed;
1461 }
1462
1463 bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
1464                           char *msg, size_t msgsize)
1465 {
1466         if ((err == ENOENT || err == ENXIO) &&
1467             evsel->attr.type   == PERF_TYPE_HARDWARE &&
1468             evsel->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
1469                 /*
1470                  * If it's cycles then fall back to hrtimer based
1471                  * cpu-clock-tick sw counter, which is always available even if
1472                  * no PMU support.
1473                  *
1474                  * PPC returns ENXIO until 2.6.37 (behavior changed with commit
1475                  * b0a873e).
1476                  */
1477                 scnprintf(msg, msgsize, "%s",
1478 "The cycles event is not supported, trying to fall back to cpu-clock-ticks");
1479
1480                 evsel->attr.type   = PERF_TYPE_SOFTWARE;
1481                 evsel->attr.config = PERF_COUNT_SW_CPU_CLOCK;
1482
1483                 free(evsel->name);
1484                 evsel->name = NULL;
1485                 return true;
1486         }
1487
1488         return false;
1489 }
1490
1491 int perf_evsel__open_strerror(struct perf_evsel *evsel,
1492                               struct perf_target *target,
1493                               int err, char *msg, size_t size)
1494 {
1495         switch (err) {
1496         case EPERM:
1497         case EACCES:
1498                 return scnprintf(msg, size, "%s",
1499                  "You may not have permission to collect %sstats.\n"
1500                  "Consider tweaking /proc/sys/kernel/perf_event_paranoid:\n"
1501                  " -1 - Not paranoid at all\n"
1502                  "  0 - Disallow raw tracepoint access for unpriv\n"
1503                  "  1 - Disallow cpu events for unpriv\n"
1504                  "  2 - Disallow kernel profiling for unpriv",
1505                                  target->system_wide ? "system-wide " : "");
1506         case ENOENT:
1507                 return scnprintf(msg, size, "The %s event is not supported.",
1508                                  perf_evsel__name(evsel));
1509         case EMFILE:
1510                 return scnprintf(msg, size, "%s",
1511                          "Too many events are opened.\n"
1512                          "Try again after reducing the number of events.");
1513         case ENODEV:
1514                 if (target->cpu_list)
1515                         return scnprintf(msg, size, "%s",
1516          "No such device - did you specify an out-of-range profile CPU?\n");
1517                 break;
1518         case EOPNOTSUPP:
1519                 if (evsel->attr.precise_ip)
1520                         return scnprintf(msg, size, "%s",
1521         "\'precise\' request may not be supported. Try removing 'p' modifier.");
1522 #if defined(__i386__) || defined(__x86_64__)
1523                 if (evsel->attr.type == PERF_TYPE_HARDWARE)
1524                         return scnprintf(msg, size, "%s",
1525         "No hardware sampling interrupt available.\n"
1526         "No APIC? If so then you can boot the kernel with the \"lapic\" boot parameter to force-enable it.");
1527 #endif
1528                 break;
1529         default:
1530                 break;
1531         }
1532
1533         return scnprintf(msg, size,
1534         "The sys_perf_event_open() syscall returned with %d (%s) for event (%s).  \n"
1535         "/bin/dmesg may provide additional information.\n"
1536         "No CONFIG_PERF_EVENTS=y kernel support configured?\n",
1537                          err, strerror(err), perf_evsel__name(evsel));
1538 }