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perf_counter tools: Use fork and remove munmap events
[deliverable/linux.git] / Documentation / perf_counter / builtin-top.c
1 /*
2 * builtin-top.c
3 *
4 * Builtin top command: Display a continuously updated profile of
5 * any workload, CPU or specific PID.
6 *
7 * Copyright (C) 2008, Red Hat Inc, Ingo Molnar <mingo@redhat.com>
8 *
9 * Improvements and fixes by:
10 *
11 * Arjan van de Ven <arjan@linux.intel.com>
12 * Yanmin Zhang <yanmin.zhang@intel.com>
13 * Wu Fengguang <fengguang.wu@intel.com>
14 * Mike Galbraith <efault@gmx.de>
15 * Paul Mackerras <paulus@samba.org>
16 *
17 * Released under the GPL v2. (and only v2, not any later version)
18 */
19 #include "builtin.h"
20
21 #include "perf.h"
22
23 #include "util/symbol.h"
24 #include "util/color.h"
25 #include "util/util.h"
26 #include "util/rbtree.h"
27 #include "util/parse-options.h"
28 #include "util/parse-events.h"
29
30 #include <assert.h>
31 #include <fcntl.h>
32
33 #include <stdio.h>
34
35 #include <errno.h>
36 #include <time.h>
37 #include <sched.h>
38 #include <pthread.h>
39
40 #include <sys/syscall.h>
41 #include <sys/ioctl.h>
42 #include <sys/poll.h>
43 #include <sys/prctl.h>
44 #include <sys/wait.h>
45 #include <sys/uio.h>
46 #include <sys/mman.h>
47
48 #include <linux/unistd.h>
49 #include <linux/types.h>
50
51 static int system_wide = 0;
52
53 static __u64 default_event_id[MAX_COUNTERS] = {
54 EID(PERF_TYPE_SOFTWARE, PERF_COUNT_TASK_CLOCK),
55 EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CONTEXT_SWITCHES),
56 EID(PERF_TYPE_SOFTWARE, PERF_COUNT_CPU_MIGRATIONS),
57 EID(PERF_TYPE_SOFTWARE, PERF_COUNT_PAGE_FAULTS),
58
59 EID(PERF_TYPE_HARDWARE, PERF_COUNT_CPU_CYCLES),
60 EID(PERF_TYPE_HARDWARE, PERF_COUNT_INSTRUCTIONS),
61 EID(PERF_TYPE_HARDWARE, PERF_COUNT_CACHE_REFERENCES),
62 EID(PERF_TYPE_HARDWARE, PERF_COUNT_CACHE_MISSES),
63 };
64 static int default_interval = 100000;
65 static int event_count[MAX_COUNTERS];
66 static int fd[MAX_NR_CPUS][MAX_COUNTERS];
67
68 static __u64 count_filter = 5;
69 static int print_entries = 15;
70
71 static int target_pid = -1;
72 static int profile_cpu = -1;
73 static int nr_cpus = 0;
74 static unsigned int realtime_prio = 0;
75 static int group = 0;
76 static unsigned int page_size;
77 static unsigned int mmap_pages = 16;
78 static int freq = 0;
79
80 static char *sym_filter;
81 static unsigned long filter_start;
82 static unsigned long filter_end;
83
84 static int delay_secs = 2;
85 static int zero;
86 static int dump_symtab;
87
88 static const unsigned int default_count[] = {
89 1000000,
90 1000000,
91 10000,
92 10000,
93 1000000,
94 10000,
95 };
96
97 /*
98 * Symbols
99 */
100
101 static uint64_t min_ip;
102 static uint64_t max_ip = -1ll;
103
104 struct sym_entry {
105 struct rb_node rb_node;
106 struct list_head node;
107 unsigned long count[MAX_COUNTERS];
108 unsigned long snap_count;
109 double weight;
110 int skip;
111 };
112
113 struct sym_entry *sym_filter_entry;
114
115 struct dso *kernel_dso;
116
117 /*
118 * Symbols will be added here in record_ip and will get out
119 * after decayed.
120 */
121 static LIST_HEAD(active_symbols);
122 static pthread_mutex_t active_symbols_lock = PTHREAD_MUTEX_INITIALIZER;
123
124 /*
125 * Ordering weight: count-1 * count-2 * ... / count-n
126 */
127 static double sym_weight(const struct sym_entry *sym)
128 {
129 double weight = sym->snap_count;
130 int counter;
131
132 for (counter = 1; counter < nr_counters-1; counter++)
133 weight *= sym->count[counter];
134
135 weight /= (sym->count[counter] + 1);
136
137 return weight;
138 }
139
140 static long events;
141 static long userspace_events;
142 static const char CONSOLE_CLEAR[] = "\e[H\e[2J";
143
144 static void __list_insert_active_sym(struct sym_entry *syme)
145 {
146 list_add(&syme->node, &active_symbols);
147 }
148
149 static void list_remove_active_sym(struct sym_entry *syme)
150 {
151 pthread_mutex_lock(&active_symbols_lock);
152 list_del_init(&syme->node);
153 pthread_mutex_unlock(&active_symbols_lock);
154 }
155
156 static void rb_insert_active_sym(struct rb_root *tree, struct sym_entry *se)
157 {
158 struct rb_node **p = &tree->rb_node;
159 struct rb_node *parent = NULL;
160 struct sym_entry *iter;
161
162 while (*p != NULL) {
163 parent = *p;
164 iter = rb_entry(parent, struct sym_entry, rb_node);
165
166 if (se->weight > iter->weight)
167 p = &(*p)->rb_left;
168 else
169 p = &(*p)->rb_right;
170 }
171
172 rb_link_node(&se->rb_node, parent, p);
173 rb_insert_color(&se->rb_node, tree);
174 }
175
176 static void print_sym_table(void)
177 {
178 int printed = 0, j;
179 int counter;
180 float events_per_sec = events/delay_secs;
181 float kevents_per_sec = (events-userspace_events)/delay_secs;
182 float sum_kevents = 0.0;
183 struct sym_entry *syme, *n;
184 struct rb_root tmp = RB_ROOT;
185 struct rb_node *nd;
186
187 events = userspace_events = 0;
188
189 /* Sort the active symbols */
190 pthread_mutex_lock(&active_symbols_lock);
191 syme = list_entry(active_symbols.next, struct sym_entry, node);
192 pthread_mutex_unlock(&active_symbols_lock);
193
194 list_for_each_entry_safe_from(syme, n, &active_symbols, node) {
195 syme->snap_count = syme->count[0];
196 if (syme->snap_count != 0) {
197 syme->weight = sym_weight(syme);
198 rb_insert_active_sym(&tmp, syme);
199 sum_kevents += syme->snap_count;
200
201 for (j = 0; j < nr_counters; j++)
202 syme->count[j] = zero ? 0 : syme->count[j] * 7 / 8;
203 } else
204 list_remove_active_sym(syme);
205 }
206
207 write(1, CONSOLE_CLEAR, strlen(CONSOLE_CLEAR));
208
209 printf(
210 "------------------------------------------------------------------------------\n");
211 printf( " PerfTop:%8.0f irqs/sec kernel:%4.1f%% [",
212 events_per_sec,
213 100.0 - (100.0*((events_per_sec-kevents_per_sec)/events_per_sec)));
214
215 if (nr_counters == 1)
216 printf("%d ", event_count[0]);
217
218 for (counter = 0; counter < nr_counters; counter++) {
219 if (counter)
220 printf("/");
221
222 printf("%s", event_name(counter));
223 }
224
225 printf( "], ");
226
227 if (target_pid != -1)
228 printf(" (target_pid: %d", target_pid);
229 else
230 printf(" (all");
231
232 if (profile_cpu != -1)
233 printf(", cpu: %d)\n", profile_cpu);
234 else {
235 if (target_pid != -1)
236 printf(")\n");
237 else
238 printf(", %d CPUs)\n", nr_cpus);
239 }
240
241 printf("------------------------------------------------------------------------------\n\n");
242
243 if (nr_counters == 1)
244 printf(" events pcnt");
245 else
246 printf(" weight events pcnt");
247
248 printf(" RIP kernel function\n"
249 " ______ ______ _____ ________________ _______________\n\n"
250 );
251
252 for (nd = rb_first(&tmp); nd; nd = rb_next(nd)) {
253 struct sym_entry *syme = rb_entry(nd, struct sym_entry, rb_node);
254 struct symbol *sym = (struct symbol *)(syme + 1);
255 char *color = PERF_COLOR_NORMAL;
256 double pcnt;
257
258 if (++printed > print_entries || syme->snap_count < count_filter)
259 continue;
260
261 pcnt = 100.0 - (100.0 * ((sum_kevents - syme->snap_count) /
262 sum_kevents));
263
264 /*
265 * We color high-overhead entries in red, low-overhead
266 * entries in green - and keep the middle ground normal:
267 */
268 if (pcnt >= 5.0)
269 color = PERF_COLOR_RED;
270 if (pcnt < 0.5)
271 color = PERF_COLOR_GREEN;
272
273 if (nr_counters == 1)
274 printf("%19.2f - ", syme->weight);
275 else
276 printf("%8.1f %10ld - ", syme->weight, syme->snap_count);
277
278 color_fprintf(stdout, color, "%4.1f%%", pcnt);
279 printf(" - %016llx : %s\n", sym->start, sym->name);
280 }
281
282 {
283 struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
284
285 if (poll(&stdin_poll, 1, 0) == 1) {
286 printf("key pressed - exiting.\n");
287 exit(0);
288 }
289 }
290 }
291
292 static void *display_thread(void *arg)
293 {
294 printf("PerfTop refresh period: %d seconds\n", delay_secs);
295
296 while (!sleep(delay_secs))
297 print_sym_table();
298
299 return NULL;
300 }
301
302 static int symbol_filter(struct dso *self, struct symbol *sym)
303 {
304 static int filter_match;
305 struct sym_entry *syme;
306 const char *name = sym->name;
307
308 if (!strcmp(name, "_text") ||
309 !strcmp(name, "_etext") ||
310 !strcmp(name, "_sinittext") ||
311 !strncmp("init_module", name, 11) ||
312 !strncmp("cleanup_module", name, 14) ||
313 strstr(name, "_text_start") ||
314 strstr(name, "_text_end"))
315 return 1;
316
317 syme = dso__sym_priv(self, sym);
318 /* Tag events to be skipped. */
319 if (!strcmp("default_idle", name) ||
320 !strcmp("cpu_idle", name) ||
321 !strcmp("enter_idle", name) ||
322 !strcmp("exit_idle", name) ||
323 !strcmp("mwait_idle", name))
324 syme->skip = 1;
325
326 if (filter_match == 1) {
327 filter_end = sym->start;
328 filter_match = -1;
329 if (filter_end - filter_start > 10000) {
330 fprintf(stderr,
331 "hm, too large filter symbol <%s> - skipping.\n",
332 sym_filter);
333 fprintf(stderr, "symbol filter start: %016lx\n",
334 filter_start);
335 fprintf(stderr, " end: %016lx\n",
336 filter_end);
337 filter_end = filter_start = 0;
338 sym_filter = NULL;
339 sleep(1);
340 }
341 }
342
343 if (filter_match == 0 && sym_filter && !strcmp(name, sym_filter)) {
344 filter_match = 1;
345 filter_start = sym->start;
346 }
347
348
349 return 0;
350 }
351
352 static int parse_symbols(void)
353 {
354 struct rb_node *node;
355 struct symbol *sym;
356
357 kernel_dso = dso__new("[kernel]", sizeof(struct sym_entry));
358 if (kernel_dso == NULL)
359 return -1;
360
361 if (dso__load_kernel(kernel_dso, NULL, symbol_filter, 1) != 0)
362 goto out_delete_dso;
363
364 node = rb_first(&kernel_dso->syms);
365 sym = rb_entry(node, struct symbol, rb_node);
366 min_ip = sym->start;
367
368 node = rb_last(&kernel_dso->syms);
369 sym = rb_entry(node, struct symbol, rb_node);
370 max_ip = sym->end;
371
372 if (dump_symtab)
373 dso__fprintf(kernel_dso, stderr);
374
375 return 0;
376
377 out_delete_dso:
378 dso__delete(kernel_dso);
379 kernel_dso = NULL;
380 return -1;
381 }
382
383 #define TRACE_COUNT 3
384
385 /*
386 * Binary search in the histogram table and record the hit:
387 */
388 static void record_ip(uint64_t ip, int counter)
389 {
390 struct symbol *sym = dso__find_symbol(kernel_dso, ip);
391
392 if (sym != NULL) {
393 struct sym_entry *syme = dso__sym_priv(kernel_dso, sym);
394
395 if (!syme->skip) {
396 syme->count[counter]++;
397 pthread_mutex_lock(&active_symbols_lock);
398 if (list_empty(&syme->node) || !syme->node.next)
399 __list_insert_active_sym(syme);
400 pthread_mutex_unlock(&active_symbols_lock);
401 return;
402 }
403 }
404
405 events--;
406 }
407
408 static void process_event(uint64_t ip, int counter)
409 {
410 events++;
411
412 if (ip < min_ip || ip > max_ip) {
413 userspace_events++;
414 return;
415 }
416
417 record_ip(ip, counter);
418 }
419
420 struct mmap_data {
421 int counter;
422 void *base;
423 unsigned int mask;
424 unsigned int prev;
425 };
426
427 static unsigned int mmap_read_head(struct mmap_data *md)
428 {
429 struct perf_counter_mmap_page *pc = md->base;
430 int head;
431
432 head = pc->data_head;
433 rmb();
434
435 return head;
436 }
437
438 struct timeval last_read, this_read;
439
440 static void mmap_read(struct mmap_data *md)
441 {
442 unsigned int head = mmap_read_head(md);
443 unsigned int old = md->prev;
444 unsigned char *data = md->base + page_size;
445 int diff;
446
447 gettimeofday(&this_read, NULL);
448
449 /*
450 * If we're further behind than half the buffer, there's a chance
451 * the writer will bite our tail and screw up the events under us.
452 *
453 * If we somehow ended up ahead of the head, we got messed up.
454 *
455 * In either case, truncate and restart at head.
456 */
457 diff = head - old;
458 if (diff > md->mask / 2 || diff < 0) {
459 struct timeval iv;
460 unsigned long msecs;
461
462 timersub(&this_read, &last_read, &iv);
463 msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
464
465 fprintf(stderr, "WARNING: failed to keep up with mmap data."
466 " Last read %lu msecs ago.\n", msecs);
467
468 /*
469 * head points to a known good entry, start there.
470 */
471 old = head;
472 }
473
474 last_read = this_read;
475
476 for (; old != head;) {
477 struct ip_event {
478 struct perf_event_header header;
479 __u64 ip;
480 __u32 pid, target_pid;
481 };
482 struct mmap_event {
483 struct perf_event_header header;
484 __u32 pid, target_pid;
485 __u64 start;
486 __u64 len;
487 __u64 pgoff;
488 char filename[PATH_MAX];
489 };
490
491 typedef union event_union {
492 struct perf_event_header header;
493 struct ip_event ip;
494 struct mmap_event mmap;
495 } event_t;
496
497 event_t *event = (event_t *)&data[old & md->mask];
498
499 event_t event_copy;
500
501 size_t size = event->header.size;
502
503 /*
504 * Event straddles the mmap boundary -- header should always
505 * be inside due to u64 alignment of output.
506 */
507 if ((old & md->mask) + size != ((old + size) & md->mask)) {
508 unsigned int offset = old;
509 unsigned int len = min(sizeof(*event), size), cpy;
510 void *dst = &event_copy;
511
512 do {
513 cpy = min(md->mask + 1 - (offset & md->mask), len);
514 memcpy(dst, &data[offset & md->mask], cpy);
515 offset += cpy;
516 dst += cpy;
517 len -= cpy;
518 } while (len);
519
520 event = &event_copy;
521 }
522
523 old += size;
524
525 if (event->header.misc & PERF_EVENT_MISC_OVERFLOW) {
526 if (event->header.type & PERF_SAMPLE_IP)
527 process_event(event->ip.ip, md->counter);
528 }
529 }
530
531 md->prev = old;
532 }
533
534 static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS];
535 static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
536
537 static int __cmd_top(void)
538 {
539 struct perf_counter_attr attr;
540 pthread_t thread;
541 int i, counter, group_fd, nr_poll = 0;
542 unsigned int cpu;
543 int ret;
544
545 for (i = 0; i < nr_cpus; i++) {
546 group_fd = -1;
547 for (counter = 0; counter < nr_counters; counter++) {
548
549 cpu = profile_cpu;
550 if (target_pid == -1 && profile_cpu == -1)
551 cpu = i;
552
553 memset(&attr, 0, sizeof(attr));
554 attr.config = event_id[counter];
555 attr.sample_period = event_count[counter];
556 attr.sample_type = PERF_SAMPLE_IP | PERF_SAMPLE_TID;
557 attr.freq = freq;
558
559 fd[i][counter] = sys_perf_counter_open(&attr, target_pid, cpu, group_fd, 0);
560 if (fd[i][counter] < 0) {
561 int err = errno;
562
563 error("syscall returned with %d (%s)\n",
564 fd[i][counter], strerror(err));
565 if (err == EPERM)
566 printf("Are you root?\n");
567 exit(-1);
568 }
569 assert(fd[i][counter] >= 0);
570 fcntl(fd[i][counter], F_SETFL, O_NONBLOCK);
571
572 /*
573 * First counter acts as the group leader:
574 */
575 if (group && group_fd == -1)
576 group_fd = fd[i][counter];
577
578 event_array[nr_poll].fd = fd[i][counter];
579 event_array[nr_poll].events = POLLIN;
580 nr_poll++;
581
582 mmap_array[i][counter].counter = counter;
583 mmap_array[i][counter].prev = 0;
584 mmap_array[i][counter].mask = mmap_pages*page_size - 1;
585 mmap_array[i][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
586 PROT_READ, MAP_SHARED, fd[i][counter], 0);
587 if (mmap_array[i][counter].base == MAP_FAILED)
588 die("failed to mmap with %d (%s)\n", errno, strerror(errno));
589 }
590 }
591
592 if (pthread_create(&thread, NULL, display_thread, NULL)) {
593 printf("Could not create display thread.\n");
594 exit(-1);
595 }
596
597 if (realtime_prio) {
598 struct sched_param param;
599
600 param.sched_priority = realtime_prio;
601 if (sched_setscheduler(0, SCHED_FIFO, &param)) {
602 printf("Could not set realtime priority.\n");
603 exit(-1);
604 }
605 }
606
607 while (1) {
608 int hits = events;
609
610 for (i = 0; i < nr_cpus; i++) {
611 for (counter = 0; counter < nr_counters; counter++)
612 mmap_read(&mmap_array[i][counter]);
613 }
614
615 if (hits == events)
616 ret = poll(event_array, nr_poll, 100);
617 }
618
619 return 0;
620 }
621
622 static const char * const top_usage[] = {
623 "perf top [<options>]",
624 NULL
625 };
626
627 static char events_help_msg[EVENTS_HELP_MAX];
628
629 static const struct option options[] = {
630 OPT_CALLBACK('e', "event", NULL, "event",
631 events_help_msg, parse_events),
632 OPT_INTEGER('c', "count", &default_interval,
633 "event period to sample"),
634 OPT_INTEGER('p', "pid", &target_pid,
635 "profile events on existing pid"),
636 OPT_BOOLEAN('a', "all-cpus", &system_wide,
637 "system-wide collection from all CPUs"),
638 OPT_INTEGER('C', "CPU", &profile_cpu,
639 "CPU to profile on"),
640 OPT_INTEGER('m', "mmap-pages", &mmap_pages,
641 "number of mmap data pages"),
642 OPT_INTEGER('r', "realtime", &realtime_prio,
643 "collect data with this RT SCHED_FIFO priority"),
644 OPT_INTEGER('d', "delay", &delay_secs,
645 "number of seconds to delay between refreshes"),
646 OPT_BOOLEAN('D', "dump-symtab", &dump_symtab,
647 "dump the symbol table used for profiling"),
648 OPT_INTEGER('f', "count-filter", &count_filter,
649 "only display functions with more events than this"),
650 OPT_BOOLEAN('g', "group", &group,
651 "put the counters into a counter group"),
652 OPT_STRING('s', "sym-filter", &sym_filter, "pattern",
653 "only display symbols matchig this pattern"),
654 OPT_BOOLEAN('z', "zero", &group,
655 "zero history across updates"),
656 OPT_INTEGER('F', "freq", &freq,
657 "profile at this frequency"),
658 OPT_INTEGER('E', "entries", &print_entries,
659 "display this many functions"),
660 OPT_END()
661 };
662
663 int cmd_top(int argc, const char **argv, const char *prefix)
664 {
665 int counter;
666
667 page_size = sysconf(_SC_PAGE_SIZE);
668
669 create_events_help(events_help_msg);
670 memcpy(event_id, default_event_id, sizeof(default_event_id));
671
672 argc = parse_options(argc, argv, options, top_usage, 0);
673 if (argc)
674 usage_with_options(top_usage, options);
675
676 if (freq) {
677 default_interval = freq;
678 freq = 1;
679 }
680
681 /* CPU and PID are mutually exclusive */
682 if (target_pid != -1 && profile_cpu != -1) {
683 printf("WARNING: PID switch overriding CPU\n");
684 sleep(1);
685 profile_cpu = -1;
686 }
687
688 if (!nr_counters) {
689 nr_counters = 1;
690 event_id[0] = 0;
691 }
692
693 for (counter = 0; counter < nr_counters; counter++) {
694 if (event_count[counter])
695 continue;
696
697 event_count[counter] = default_interval;
698 }
699
700 nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
701 assert(nr_cpus <= MAX_NR_CPUS);
702 assert(nr_cpus >= 0);
703
704 if (target_pid != -1 || profile_cpu != -1)
705 nr_cpus = 1;
706
707 parse_symbols();
708
709 return __cmd_top();
710 }
Linux kernel - Deliverables
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