Merge branch 'next' into for-linus
[firefly-linux-kernel-4.4.55.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 "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 int perf_evsel__alloc_counts(struct perf_evsel *evsel, int ncpus)
637 {
638         evsel->counts = zalloc((sizeof(*evsel->counts) +
639                                 (ncpus * sizeof(struct perf_counts_values))));
640         return evsel->counts != NULL ? 0 : -ENOMEM;
641 }
642
643 void perf_evsel__free_fd(struct perf_evsel *evsel)
644 {
645         xyarray__delete(evsel->fd);
646         evsel->fd = NULL;
647 }
648
649 void perf_evsel__free_id(struct perf_evsel *evsel)
650 {
651         xyarray__delete(evsel->sample_id);
652         evsel->sample_id = NULL;
653         free(evsel->id);
654         evsel->id = NULL;
655 }
656
657 void perf_evsel__close_fd(struct perf_evsel *evsel, int ncpus, int nthreads)
658 {
659         int cpu, thread;
660
661         for (cpu = 0; cpu < ncpus; cpu++)
662                 for (thread = 0; thread < nthreads; ++thread) {
663                         close(FD(evsel, cpu, thread));
664                         FD(evsel, cpu, thread) = -1;
665                 }
666 }
667
668 void perf_evsel__free_counts(struct perf_evsel *evsel)
669 {
670         free(evsel->counts);
671 }
672
673 void perf_evsel__exit(struct perf_evsel *evsel)
674 {
675         assert(list_empty(&evsel->node));
676         xyarray__delete(evsel->fd);
677         xyarray__delete(evsel->sample_id);
678         free(evsel->id);
679 }
680
681 void perf_evsel__delete(struct perf_evsel *evsel)
682 {
683         perf_evsel__exit(evsel);
684         close_cgroup(evsel->cgrp);
685         free(evsel->group_name);
686         if (evsel->tp_format)
687                 pevent_free_format(evsel->tp_format);
688         free(evsel->name);
689         free(evsel);
690 }
691
692 static inline void compute_deltas(struct perf_evsel *evsel,
693                                   int cpu,
694                                   struct perf_counts_values *count)
695 {
696         struct perf_counts_values tmp;
697
698         if (!evsel->prev_raw_counts)
699                 return;
700
701         if (cpu == -1) {
702                 tmp = evsel->prev_raw_counts->aggr;
703                 evsel->prev_raw_counts->aggr = *count;
704         } else {
705                 tmp = evsel->prev_raw_counts->cpu[cpu];
706                 evsel->prev_raw_counts->cpu[cpu] = *count;
707         }
708
709         count->val = count->val - tmp.val;
710         count->ena = count->ena - tmp.ena;
711         count->run = count->run - tmp.run;
712 }
713
714 int __perf_evsel__read_on_cpu(struct perf_evsel *evsel,
715                               int cpu, int thread, bool scale)
716 {
717         struct perf_counts_values count;
718         size_t nv = scale ? 3 : 1;
719
720         if (FD(evsel, cpu, thread) < 0)
721                 return -EINVAL;
722
723         if (evsel->counts == NULL && perf_evsel__alloc_counts(evsel, cpu + 1) < 0)
724                 return -ENOMEM;
725
726         if (readn(FD(evsel, cpu, thread), &count, nv * sizeof(u64)) < 0)
727                 return -errno;
728
729         compute_deltas(evsel, cpu, &count);
730
731         if (scale) {
732                 if (count.run == 0)
733                         count.val = 0;
734                 else if (count.run < count.ena)
735                         count.val = (u64)((double)count.val * count.ena / count.run + 0.5);
736         } else
737                 count.ena = count.run = 0;
738
739         evsel->counts->cpu[cpu] = count;
740         return 0;
741 }
742
743 int __perf_evsel__read(struct perf_evsel *evsel,
744                        int ncpus, int nthreads, bool scale)
745 {
746         size_t nv = scale ? 3 : 1;
747         int cpu, thread;
748         struct perf_counts_values *aggr = &evsel->counts->aggr, count;
749
750         aggr->val = aggr->ena = aggr->run = 0;
751
752         for (cpu = 0; cpu < ncpus; cpu++) {
753                 for (thread = 0; thread < nthreads; thread++) {
754                         if (FD(evsel, cpu, thread) < 0)
755                                 continue;
756
757                         if (readn(FD(evsel, cpu, thread),
758                                   &count, nv * sizeof(u64)) < 0)
759                                 return -errno;
760
761                         aggr->val += count.val;
762                         if (scale) {
763                                 aggr->ena += count.ena;
764                                 aggr->run += count.run;
765                         }
766                 }
767         }
768
769         compute_deltas(evsel, -1, aggr);
770
771         evsel->counts->scaled = 0;
772         if (scale) {
773                 if (aggr->run == 0) {
774                         evsel->counts->scaled = -1;
775                         aggr->val = 0;
776                         return 0;
777                 }
778
779                 if (aggr->run < aggr->ena) {
780                         evsel->counts->scaled = 1;
781                         aggr->val = (u64)((double)aggr->val * aggr->ena / aggr->run + 0.5);
782                 }
783         } else
784                 aggr->ena = aggr->run = 0;
785
786         return 0;
787 }
788
789 static int get_group_fd(struct perf_evsel *evsel, int cpu, int thread)
790 {
791         struct perf_evsel *leader = evsel->leader;
792         int fd;
793
794         if (perf_evsel__is_group_leader(evsel))
795                 return -1;
796
797         /*
798          * Leader must be already processed/open,
799          * if not it's a bug.
800          */
801         BUG_ON(!leader->fd);
802
803         fd = FD(leader, cpu, thread);
804         BUG_ON(fd == -1);
805
806         return fd;
807 }
808
809 static int __perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
810                               struct thread_map *threads)
811 {
812         int cpu, thread;
813         unsigned long flags = 0;
814         int pid = -1, err;
815
816         if (evsel->fd == NULL &&
817             perf_evsel__alloc_fd(evsel, cpus->nr, threads->nr) < 0)
818                 return -ENOMEM;
819
820         if (evsel->cgrp) {
821                 flags = PERF_FLAG_PID_CGROUP;
822                 pid = evsel->cgrp->fd;
823         }
824
825 fallback_missing_features:
826         if (perf_missing_features.exclude_guest)
827                 evsel->attr.exclude_guest = evsel->attr.exclude_host = 0;
828 retry_sample_id:
829         if (perf_missing_features.sample_id_all)
830                 evsel->attr.sample_id_all = 0;
831
832         for (cpu = 0; cpu < cpus->nr; cpu++) {
833
834                 for (thread = 0; thread < threads->nr; thread++) {
835                         int group_fd;
836
837                         if (!evsel->cgrp)
838                                 pid = threads->map[thread];
839
840                         group_fd = get_group_fd(evsel, cpu, thread);
841
842                         FD(evsel, cpu, thread) = sys_perf_event_open(&evsel->attr,
843                                                                      pid,
844                                                                      cpus->map[cpu],
845                                                                      group_fd, flags);
846                         if (FD(evsel, cpu, thread) < 0) {
847                                 err = -errno;
848                                 goto try_fallback;
849                         }
850                 }
851         }
852
853         return 0;
854
855 try_fallback:
856         if (err != -EINVAL || cpu > 0 || thread > 0)
857                 goto out_close;
858
859         if (!perf_missing_features.exclude_guest &&
860             (evsel->attr.exclude_guest || evsel->attr.exclude_host)) {
861                 perf_missing_features.exclude_guest = true;
862                 goto fallback_missing_features;
863         } else if (!perf_missing_features.sample_id_all) {
864                 perf_missing_features.sample_id_all = true;
865                 goto retry_sample_id;
866         }
867
868 out_close:
869         do {
870                 while (--thread >= 0) {
871                         close(FD(evsel, cpu, thread));
872                         FD(evsel, cpu, thread) = -1;
873                 }
874                 thread = threads->nr;
875         } while (--cpu >= 0);
876         return err;
877 }
878
879 void perf_evsel__close(struct perf_evsel *evsel, int ncpus, int nthreads)
880 {
881         if (evsel->fd == NULL)
882                 return;
883
884         perf_evsel__close_fd(evsel, ncpus, nthreads);
885         perf_evsel__free_fd(evsel);
886         evsel->fd = NULL;
887 }
888
889 static struct {
890         struct cpu_map map;
891         int cpus[1];
892 } empty_cpu_map = {
893         .map.nr = 1,
894         .cpus   = { -1, },
895 };
896
897 static struct {
898         struct thread_map map;
899         int threads[1];
900 } empty_thread_map = {
901         .map.nr  = 1,
902         .threads = { -1, },
903 };
904
905 int perf_evsel__open(struct perf_evsel *evsel, struct cpu_map *cpus,
906                      struct thread_map *threads)
907 {
908         if (cpus == NULL) {
909                 /* Work around old compiler warnings about strict aliasing */
910                 cpus = &empty_cpu_map.map;
911         }
912
913         if (threads == NULL)
914                 threads = &empty_thread_map.map;
915
916         return __perf_evsel__open(evsel, cpus, threads);
917 }
918
919 int perf_evsel__open_per_cpu(struct perf_evsel *evsel,
920                              struct cpu_map *cpus)
921 {
922         return __perf_evsel__open(evsel, cpus, &empty_thread_map.map);
923 }
924
925 int perf_evsel__open_per_thread(struct perf_evsel *evsel,
926                                 struct thread_map *threads)
927 {
928         return __perf_evsel__open(evsel, &empty_cpu_map.map, threads);
929 }
930
931 static int perf_evsel__parse_id_sample(const struct perf_evsel *evsel,
932                                        const union perf_event *event,
933                                        struct perf_sample *sample)
934 {
935         u64 type = evsel->attr.sample_type;
936         const u64 *array = event->sample.array;
937         bool swapped = evsel->needs_swap;
938         union u64_swap u;
939
940         array += ((event->header.size -
941                    sizeof(event->header)) / sizeof(u64)) - 1;
942
943         if (type & PERF_SAMPLE_CPU) {
944                 u.val64 = *array;
945                 if (swapped) {
946                         /* undo swap of u64, then swap on individual u32s */
947                         u.val64 = bswap_64(u.val64);
948                         u.val32[0] = bswap_32(u.val32[0]);
949                 }
950
951                 sample->cpu = u.val32[0];
952                 array--;
953         }
954
955         if (type & PERF_SAMPLE_STREAM_ID) {
956                 sample->stream_id = *array;
957                 array--;
958         }
959
960         if (type & PERF_SAMPLE_ID) {
961                 sample->id = *array;
962                 array--;
963         }
964
965         if (type & PERF_SAMPLE_TIME) {
966                 sample->time = *array;
967                 array--;
968         }
969
970         if (type & PERF_SAMPLE_TID) {
971                 u.val64 = *array;
972                 if (swapped) {
973                         /* undo swap of u64, then swap on individual u32s */
974                         u.val64 = bswap_64(u.val64);
975                         u.val32[0] = bswap_32(u.val32[0]);
976                         u.val32[1] = bswap_32(u.val32[1]);
977                 }
978
979                 sample->pid = u.val32[0];
980                 sample->tid = u.val32[1];
981         }
982
983         return 0;
984 }
985
986 static bool sample_overlap(const union perf_event *event,
987                            const void *offset, u64 size)
988 {
989         const void *base = event;
990
991         if (offset + size > base + event->header.size)
992                 return true;
993
994         return false;
995 }
996
997 int perf_evsel__parse_sample(struct perf_evsel *evsel, union perf_event *event,
998                              struct perf_sample *data)
999 {
1000         u64 type = evsel->attr.sample_type;
1001         u64 regs_user = evsel->attr.sample_regs_user;
1002         bool swapped = evsel->needs_swap;
1003         const u64 *array;
1004
1005         /*
1006          * used for cross-endian analysis. See git commit 65014ab3
1007          * for why this goofiness is needed.
1008          */
1009         union u64_swap u;
1010
1011         memset(data, 0, sizeof(*data));
1012         data->cpu = data->pid = data->tid = -1;
1013         data->stream_id = data->id = data->time = -1ULL;
1014         data->period = 1;
1015
1016         if (event->header.type != PERF_RECORD_SAMPLE) {
1017                 if (!evsel->attr.sample_id_all)
1018                         return 0;
1019                 return perf_evsel__parse_id_sample(evsel, event, data);
1020         }
1021
1022         array = event->sample.array;
1023
1024         if (evsel->sample_size + sizeof(event->header) > event->header.size)
1025                 return -EFAULT;
1026
1027         if (type & PERF_SAMPLE_IP) {
1028                 data->ip = event->ip.ip;
1029                 array++;
1030         }
1031
1032         if (type & PERF_SAMPLE_TID) {
1033                 u.val64 = *array;
1034                 if (swapped) {
1035                         /* undo swap of u64, then swap on individual u32s */
1036                         u.val64 = bswap_64(u.val64);
1037                         u.val32[0] = bswap_32(u.val32[0]);
1038                         u.val32[1] = bswap_32(u.val32[1]);
1039                 }
1040
1041                 data->pid = u.val32[0];
1042                 data->tid = u.val32[1];
1043                 array++;
1044         }
1045
1046         if (type & PERF_SAMPLE_TIME) {
1047                 data->time = *array;
1048                 array++;
1049         }
1050
1051         data->addr = 0;
1052         if (type & PERF_SAMPLE_ADDR) {
1053                 data->addr = *array;
1054                 array++;
1055         }
1056
1057         data->id = -1ULL;
1058         if (type & PERF_SAMPLE_ID) {
1059                 data->id = *array;
1060                 array++;
1061         }
1062
1063         if (type & PERF_SAMPLE_STREAM_ID) {
1064                 data->stream_id = *array;
1065                 array++;
1066         }
1067
1068         if (type & PERF_SAMPLE_CPU) {
1069
1070                 u.val64 = *array;
1071                 if (swapped) {
1072                         /* undo swap of u64, then swap on individual u32s */
1073                         u.val64 = bswap_64(u.val64);
1074                         u.val32[0] = bswap_32(u.val32[0]);
1075                 }
1076
1077                 data->cpu = u.val32[0];
1078                 array++;
1079         }
1080
1081         if (type & PERF_SAMPLE_PERIOD) {
1082                 data->period = *array;
1083                 array++;
1084         }
1085
1086         if (type & PERF_SAMPLE_READ) {
1087                 fprintf(stderr, "PERF_SAMPLE_READ is unsupported for now\n");
1088                 return -1;
1089         }
1090
1091         if (type & PERF_SAMPLE_CALLCHAIN) {
1092                 if (sample_overlap(event, array, sizeof(data->callchain->nr)))
1093                         return -EFAULT;
1094
1095                 data->callchain = (struct ip_callchain *)array;
1096
1097                 if (sample_overlap(event, array, data->callchain->nr))
1098                         return -EFAULT;
1099
1100                 array += 1 + data->callchain->nr;
1101         }
1102
1103         if (type & PERF_SAMPLE_RAW) {
1104                 const u64 *pdata;
1105
1106                 u.val64 = *array;
1107                 if (WARN_ONCE(swapped,
1108                               "Endianness of raw data not corrected!\n")) {
1109                         /* undo swap of u64, then swap on individual u32s */
1110                         u.val64 = bswap_64(u.val64);
1111                         u.val32[0] = bswap_32(u.val32[0]);
1112                         u.val32[1] = bswap_32(u.val32[1]);
1113                 }
1114
1115                 if (sample_overlap(event, array, sizeof(u32)))
1116                         return -EFAULT;
1117
1118                 data->raw_size = u.val32[0];
1119                 pdata = (void *) array + sizeof(u32);
1120
1121                 if (sample_overlap(event, pdata, data->raw_size))
1122                         return -EFAULT;
1123
1124                 data->raw_data = (void *) pdata;
1125
1126                 array = (void *)array + data->raw_size + sizeof(u32);
1127         }
1128
1129         if (type & PERF_SAMPLE_BRANCH_STACK) {
1130                 u64 sz;
1131
1132                 data->branch_stack = (struct branch_stack *)array;
1133                 array++; /* nr */
1134
1135                 sz = data->branch_stack->nr * sizeof(struct branch_entry);
1136                 sz /= sizeof(u64);
1137                 array += sz;
1138         }
1139
1140         if (type & PERF_SAMPLE_REGS_USER) {
1141                 /* First u64 tells us if we have any regs in sample. */
1142                 u64 avail = *array++;
1143
1144                 if (avail) {
1145                         data->user_regs.regs = (u64 *)array;
1146                         array += hweight_long(regs_user);
1147                 }
1148         }
1149
1150         if (type & PERF_SAMPLE_STACK_USER) {
1151                 u64 size = *array++;
1152
1153                 data->user_stack.offset = ((char *)(array - 1)
1154                                           - (char *) event);
1155
1156                 if (!size) {
1157                         data->user_stack.size = 0;
1158                 } else {
1159                         data->user_stack.data = (char *)array;
1160                         array += size / sizeof(*array);
1161                         data->user_stack.size = *array;
1162                 }
1163         }
1164
1165         return 0;
1166 }
1167
1168 int perf_event__synthesize_sample(union perf_event *event, u64 type,
1169                                   const struct perf_sample *sample,
1170                                   bool swapped)
1171 {
1172         u64 *array;
1173
1174         /*
1175          * used for cross-endian analysis. See git commit 65014ab3
1176          * for why this goofiness is needed.
1177          */
1178         union u64_swap u;
1179
1180         array = event->sample.array;
1181
1182         if (type & PERF_SAMPLE_IP) {
1183                 event->ip.ip = sample->ip;
1184                 array++;
1185         }
1186
1187         if (type & PERF_SAMPLE_TID) {
1188                 u.val32[0] = sample->pid;
1189                 u.val32[1] = sample->tid;
1190                 if (swapped) {
1191                         /*
1192                          * Inverse of what is done in perf_evsel__parse_sample
1193                          */
1194                         u.val32[0] = bswap_32(u.val32[0]);
1195                         u.val32[1] = bswap_32(u.val32[1]);
1196                         u.val64 = bswap_64(u.val64);
1197                 }
1198
1199                 *array = u.val64;
1200                 array++;
1201         }
1202
1203         if (type & PERF_SAMPLE_TIME) {
1204                 *array = sample->time;
1205                 array++;
1206         }
1207
1208         if (type & PERF_SAMPLE_ADDR) {
1209                 *array = sample->addr;
1210                 array++;
1211         }
1212
1213         if (type & PERF_SAMPLE_ID) {
1214                 *array = sample->id;
1215                 array++;
1216         }
1217
1218         if (type & PERF_SAMPLE_STREAM_ID) {
1219                 *array = sample->stream_id;
1220                 array++;
1221         }
1222
1223         if (type & PERF_SAMPLE_CPU) {
1224                 u.val32[0] = sample->cpu;
1225                 if (swapped) {
1226                         /*
1227                          * Inverse of what is done in perf_evsel__parse_sample
1228                          */
1229                         u.val32[0] = bswap_32(u.val32[0]);
1230                         u.val64 = bswap_64(u.val64);
1231                 }
1232                 *array = u.val64;
1233                 array++;
1234         }
1235
1236         if (type & PERF_SAMPLE_PERIOD) {
1237                 *array = sample->period;
1238                 array++;
1239         }
1240
1241         return 0;
1242 }
1243
1244 struct format_field *perf_evsel__field(struct perf_evsel *evsel, const char *name)
1245 {
1246         return pevent_find_field(evsel->tp_format, name);
1247 }
1248
1249 void *perf_evsel__rawptr(struct perf_evsel *evsel, struct perf_sample *sample,
1250                          const char *name)
1251 {
1252         struct format_field *field = perf_evsel__field(evsel, name);
1253         int offset;
1254
1255         if (!field)
1256                 return NULL;
1257
1258         offset = field->offset;
1259
1260         if (field->flags & FIELD_IS_DYNAMIC) {
1261                 offset = *(int *)(sample->raw_data + field->offset);
1262                 offset &= 0xffff;
1263         }
1264
1265         return sample->raw_data + offset;
1266 }
1267
1268 u64 perf_evsel__intval(struct perf_evsel *evsel, struct perf_sample *sample,
1269                        const char *name)
1270 {
1271         struct format_field *field = perf_evsel__field(evsel, name);
1272         void *ptr;
1273         u64 value;
1274
1275         if (!field)
1276                 return 0;
1277
1278         ptr = sample->raw_data + field->offset;
1279
1280         switch (field->size) {
1281         case 1:
1282                 return *(u8 *)ptr;
1283         case 2:
1284                 value = *(u16 *)ptr;
1285                 break;
1286         case 4:
1287                 value = *(u32 *)ptr;
1288                 break;
1289         case 8:
1290                 value = *(u64 *)ptr;
1291                 break;
1292         default:
1293                 return 0;
1294         }
1295
1296         if (!evsel->needs_swap)
1297                 return value;
1298
1299         switch (field->size) {
1300         case 2:
1301                 return bswap_16(value);
1302         case 4:
1303                 return bswap_32(value);
1304         case 8:
1305                 return bswap_64(value);
1306         default:
1307                 return 0;
1308         }
1309
1310         return 0;
1311 }
1312
1313 static int comma_fprintf(FILE *fp, bool *first, const char *fmt, ...)
1314 {
1315         va_list args;
1316         int ret = 0;
1317
1318         if (!*first) {
1319                 ret += fprintf(fp, ",");
1320         } else {
1321                 ret += fprintf(fp, ":");
1322                 *first = false;
1323         }
1324
1325         va_start(args, fmt);
1326         ret += vfprintf(fp, fmt, args);
1327         va_end(args);
1328         return ret;
1329 }
1330
1331 static int __if_fprintf(FILE *fp, bool *first, const char *field, u64 value)
1332 {
1333         if (value == 0)
1334                 return 0;
1335
1336         return comma_fprintf(fp, first, " %s: %" PRIu64, field, value);
1337 }
1338
1339 #define if_print(field) printed += __if_fprintf(fp, &first, #field, evsel->attr.field)
1340
1341 struct bit_names {
1342         int bit;
1343         const char *name;
1344 };
1345
1346 static int bits__fprintf(FILE *fp, const char *field, u64 value,
1347                          struct bit_names *bits, bool *first)
1348 {
1349         int i = 0, printed = comma_fprintf(fp, first, " %s: ", field);
1350         bool first_bit = true;
1351
1352         do {
1353                 if (value & bits[i].bit) {
1354                         printed += fprintf(fp, "%s%s", first_bit ? "" : "|", bits[i].name);
1355                         first_bit = false;
1356                 }
1357         } while (bits[++i].name != NULL);
1358
1359         return printed;
1360 }
1361
1362 static int sample_type__fprintf(FILE *fp, bool *first, u64 value)
1363 {
1364 #define bit_name(n) { PERF_SAMPLE_##n, #n }
1365         struct bit_names bits[] = {
1366                 bit_name(IP), bit_name(TID), bit_name(TIME), bit_name(ADDR),
1367                 bit_name(READ), bit_name(CALLCHAIN), bit_name(ID), bit_name(CPU),
1368                 bit_name(PERIOD), bit_name(STREAM_ID), bit_name(RAW),
1369                 bit_name(BRANCH_STACK), bit_name(REGS_USER), bit_name(STACK_USER),
1370                 { .name = NULL, }
1371         };
1372 #undef bit_name
1373         return bits__fprintf(fp, "sample_type", value, bits, first);
1374 }
1375
1376 static int read_format__fprintf(FILE *fp, bool *first, u64 value)
1377 {
1378 #define bit_name(n) { PERF_FORMAT_##n, #n }
1379         struct bit_names bits[] = {
1380                 bit_name(TOTAL_TIME_ENABLED), bit_name(TOTAL_TIME_RUNNING),
1381                 bit_name(ID), bit_name(GROUP),
1382                 { .name = NULL, }
1383         };
1384 #undef bit_name
1385         return bits__fprintf(fp, "read_format", value, bits, first);
1386 }
1387
1388 int perf_evsel__fprintf(struct perf_evsel *evsel,
1389                         struct perf_attr_details *details, FILE *fp)
1390 {
1391         bool first = true;
1392         int printed = 0;
1393
1394         if (details->event_group) {
1395                 struct perf_evsel *pos;
1396
1397                 if (!perf_evsel__is_group_leader(evsel))
1398                         return 0;
1399
1400                 if (evsel->nr_members > 1)
1401                         printed += fprintf(fp, "%s{", evsel->group_name ?: "");
1402
1403                 printed += fprintf(fp, "%s", perf_evsel__name(evsel));
1404                 for_each_group_member(pos, evsel)
1405                         printed += fprintf(fp, ",%s", perf_evsel__name(pos));
1406
1407                 if (evsel->nr_members > 1)
1408                         printed += fprintf(fp, "}");
1409                 goto out;
1410         }
1411
1412         printed += fprintf(fp, "%s", perf_evsel__name(evsel));
1413
1414         if (details->verbose || details->freq) {
1415                 printed += comma_fprintf(fp, &first, " sample_freq=%" PRIu64,
1416                                          (u64)evsel->attr.sample_freq);
1417         }
1418
1419         if (details->verbose) {
1420                 if_print(type);
1421                 if_print(config);
1422                 if_print(config1);
1423                 if_print(config2);
1424                 if_print(size);
1425                 printed += sample_type__fprintf(fp, &first, evsel->attr.sample_type);
1426                 if (evsel->attr.read_format)
1427                         printed += read_format__fprintf(fp, &first, evsel->attr.read_format);
1428                 if_print(disabled);
1429                 if_print(inherit);
1430                 if_print(pinned);
1431                 if_print(exclusive);
1432                 if_print(exclude_user);
1433                 if_print(exclude_kernel);
1434                 if_print(exclude_hv);
1435                 if_print(exclude_idle);
1436                 if_print(mmap);
1437                 if_print(comm);
1438                 if_print(freq);
1439                 if_print(inherit_stat);
1440                 if_print(enable_on_exec);
1441                 if_print(task);
1442                 if_print(watermark);
1443                 if_print(precise_ip);
1444                 if_print(mmap_data);
1445                 if_print(sample_id_all);
1446                 if_print(exclude_host);
1447                 if_print(exclude_guest);
1448                 if_print(__reserved_1);
1449                 if_print(wakeup_events);
1450                 if_print(bp_type);
1451                 if_print(branch_sample_type);
1452         }
1453 out:
1454         fputc('\n', fp);
1455         return ++printed;
1456 }
1457
1458 bool perf_evsel__fallback(struct perf_evsel *evsel, int err,
1459                           char *msg, size_t msgsize)
1460 {
1461         if ((err == ENOENT || err == ENXIO) &&
1462             evsel->attr.type   == PERF_TYPE_HARDWARE &&
1463             evsel->attr.config == PERF_COUNT_HW_CPU_CYCLES) {
1464                 /*
1465                  * If it's cycles then fall back to hrtimer based
1466                  * cpu-clock-tick sw counter, which is always available even if
1467                  * no PMU support.
1468                  *
1469                  * PPC returns ENXIO until 2.6.37 (behavior changed with commit
1470                  * b0a873e).
1471                  */
1472                 scnprintf(msg, msgsize, "%s",
1473 "The cycles event is not supported, trying to fall back to cpu-clock-ticks");
1474
1475                 evsel->attr.type   = PERF_TYPE_SOFTWARE;
1476                 evsel->attr.config = PERF_COUNT_SW_CPU_CLOCK;
1477
1478                 free(evsel->name);
1479                 evsel->name = NULL;
1480                 return true;
1481         }
1482
1483         return false;
1484 }
1485
1486 int perf_evsel__open_strerror(struct perf_evsel *evsel,
1487                               struct perf_target *target,
1488                               int err, char *msg, size_t size)
1489 {
1490         switch (err) {
1491         case EPERM:
1492         case EACCES:
1493                 return scnprintf(msg, size, "%s",
1494                  "You may not have permission to collect %sstats.\n"
1495                  "Consider tweaking /proc/sys/kernel/perf_event_paranoid:\n"
1496                  " -1 - Not paranoid at all\n"
1497                  "  0 - Disallow raw tracepoint access for unpriv\n"
1498                  "  1 - Disallow cpu events for unpriv\n"
1499                  "  2 - Disallow kernel profiling for unpriv",
1500                                  target->system_wide ? "system-wide " : "");
1501         case ENOENT:
1502                 return scnprintf(msg, size, "The %s event is not supported.",
1503                                  perf_evsel__name(evsel));
1504         case EMFILE:
1505                 return scnprintf(msg, size, "%s",
1506                          "Too many events are opened.\n"
1507                          "Try again after reducing the number of events.");
1508         case ENODEV:
1509                 if (target->cpu_list)
1510                         return scnprintf(msg, size, "%s",
1511          "No such device - did you specify an out-of-range profile CPU?\n");
1512                 break;
1513         case EOPNOTSUPP:
1514                 if (evsel->attr.precise_ip)
1515                         return scnprintf(msg, size, "%s",
1516         "\'precise\' request may not be supported. Try removing 'p' modifier.");
1517 #if defined(__i386__) || defined(__x86_64__)
1518                 if (evsel->attr.type == PERF_TYPE_HARDWARE)
1519                         return scnprintf(msg, size, "%s",
1520         "No hardware sampling interrupt available.\n"
1521         "No APIC? If so then you can boot the kernel with the \"lapic\" boot parameter to force-enable it.");
1522 #endif
1523                 break;
1524         default:
1525                 break;
1526         }
1527
1528         return scnprintf(msg, size,
1529         "The sys_perf_event_open() syscall returned with %d (%s) for event (%s).  \n"
1530         "/bin/dmesg may provide additional information.\n"
1531         "No CONFIG_PERF_EVENTS=y kernel support configured?\n",
1532                          err, strerror(err), perf_evsel__name(evsel));
1533 }