xref: /linux/tools/perf/builtin-top.c (revision 27258e448eb301cf89e351df87aa8cb916653bf2)
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 <linux/rbtree.h>
27 #include "util/parse-options.h"
28 #include "util/parse-events.h"
29 
30 #include "util/debug.h"
31 
32 #include <assert.h>
33 #include <fcntl.h>
34 
35 #include <stdio.h>
36 #include <termios.h>
37 #include <unistd.h>
38 
39 #include <errno.h>
40 #include <time.h>
41 #include <sched.h>
42 #include <pthread.h>
43 
44 #include <sys/syscall.h>
45 #include <sys/ioctl.h>
46 #include <sys/poll.h>
47 #include <sys/prctl.h>
48 #include <sys/wait.h>
49 #include <sys/uio.h>
50 #include <sys/mman.h>
51 
52 #include <linux/unistd.h>
53 #include <linux/types.h>
54 
55 static int			fd[MAX_NR_CPUS][MAX_COUNTERS];
56 
57 static int			system_wide			=  0;
58 
59 static int			default_interval		= 100000;
60 
61 static int			count_filter			=  5;
62 static int			print_entries			= 15;
63 
64 static int			target_pid			= -1;
65 static int			inherit				=  0;
66 static int			profile_cpu			= -1;
67 static int			nr_cpus				=  0;
68 static unsigned int		realtime_prio			=  0;
69 static int			group				=  0;
70 static unsigned int		page_size;
71 static unsigned int		mmap_pages			= 16;
72 static int			freq				=  0;
73 
74 static int			delay_secs			=  2;
75 static int			zero;
76 static int			dump_symtab;
77 
78 /*
79  * Source
80  */
81 
82 struct source_line {
83 	u64			eip;
84 	unsigned long		count[MAX_COUNTERS];
85 	char			*line;
86 	struct source_line	*next;
87 };
88 
89 static char			*sym_filter			=  NULL;
90 struct sym_entry		*sym_filter_entry		=  NULL;
91 static int			sym_pcnt_filter			=  5;
92 static int			sym_counter			=  0;
93 static int			display_weighted		= -1;
94 
95 /*
96  * Symbols
97  */
98 
99 static u64			min_ip;
100 static u64			max_ip = -1ll;
101 
102 struct sym_entry {
103 	struct rb_node		rb_node;
104 	struct list_head	node;
105 	unsigned long		count[MAX_COUNTERS];
106 	unsigned long		snap_count;
107 	double			weight;
108 	int			skip;
109 	struct source_line	*source;
110 	struct source_line	*lines;
111 	struct source_line	**lines_tail;
112 	pthread_mutex_t		source_lock;
113 };
114 
115 /*
116  * Source functions
117  */
118 
119 static void parse_source(struct sym_entry *syme)
120 {
121 	struct symbol *sym;
122 	struct module *module;
123 	struct section *section = NULL;
124 	FILE *file;
125 	char command[PATH_MAX*2];
126 	const char *path = vmlinux_name;
127 	u64 start, end, len;
128 
129 	if (!syme)
130 		return;
131 
132 	if (syme->lines) {
133 		pthread_mutex_lock(&syme->source_lock);
134 		goto out_assign;
135 	}
136 
137 	sym = (struct symbol *)(syme + 1);
138 	module = sym->module;
139 
140 	if (module)
141 		path = module->path;
142 	if (!path)
143 		return;
144 
145 	start = sym->obj_start;
146 	if (!start)
147 		start = sym->start;
148 
149 	if (module) {
150 		section = module->sections->find_section(module->sections, ".text");
151 		if (section)
152 			start -= section->vma;
153 	}
154 
155 	end = start + sym->end - sym->start + 1;
156 	len = sym->end - sym->start;
157 
158 	sprintf(command, "objdump --start-address=0x%016Lx --stop-address=0x%016Lx -dS %s", start, end, path);
159 
160 	file = popen(command, "r");
161 	if (!file)
162 		return;
163 
164 	pthread_mutex_lock(&syme->source_lock);
165 	syme->lines_tail = &syme->lines;
166 	while (!feof(file)) {
167 		struct source_line *src;
168 		size_t dummy = 0;
169 		char *c;
170 
171 		src = malloc(sizeof(struct source_line));
172 		assert(src != NULL);
173 		memset(src, 0, sizeof(struct source_line));
174 
175 		if (getline(&src->line, &dummy, file) < 0)
176 			break;
177 		if (!src->line)
178 			break;
179 
180 		c = strchr(src->line, '\n');
181 		if (c)
182 			*c = 0;
183 
184 		src->next = NULL;
185 		*syme->lines_tail = src;
186 		syme->lines_tail = &src->next;
187 
188 		if (strlen(src->line)>8 && src->line[8] == ':') {
189 			src->eip = strtoull(src->line, NULL, 16);
190 			if (section)
191 				src->eip += section->vma;
192 		}
193 		if (strlen(src->line)>8 && src->line[16] == ':') {
194 			src->eip = strtoull(src->line, NULL, 16);
195 			if (section)
196 				src->eip += section->vma;
197 		}
198 	}
199 	pclose(file);
200 out_assign:
201 	sym_filter_entry = syme;
202 	pthread_mutex_unlock(&syme->source_lock);
203 }
204 
205 static void __zero_source_counters(struct sym_entry *syme)
206 {
207 	int i;
208 	struct source_line *line;
209 
210 	line = syme->lines;
211 	while (line) {
212 		for (i = 0; i < nr_counters; i++)
213 			line->count[i] = 0;
214 		line = line->next;
215 	}
216 }
217 
218 static void record_precise_ip(struct sym_entry *syme, int counter, u64 ip)
219 {
220 	struct source_line *line;
221 
222 	if (syme != sym_filter_entry)
223 		return;
224 
225 	if (pthread_mutex_trylock(&syme->source_lock))
226 		return;
227 
228 	if (!syme->source)
229 		goto out_unlock;
230 
231 	for (line = syme->lines; line; line = line->next) {
232 		if (line->eip == ip) {
233 			line->count[counter]++;
234 			break;
235 		}
236 		if (line->eip > ip)
237 			break;
238 	}
239 out_unlock:
240 	pthread_mutex_unlock(&syme->source_lock);
241 }
242 
243 static void lookup_sym_source(struct sym_entry *syme)
244 {
245 	struct symbol *symbol = (struct symbol *)(syme + 1);
246 	struct source_line *line;
247 	char pattern[PATH_MAX];
248 	char *idx;
249 
250 	sprintf(pattern, "<%s>:", symbol->name);
251 
252 	if (symbol->module) {
253 		idx = strstr(pattern, "\t");
254 		if (idx)
255 			*idx = 0;
256 	}
257 
258 	pthread_mutex_lock(&syme->source_lock);
259 	for (line = syme->lines; line; line = line->next) {
260 		if (strstr(line->line, pattern)) {
261 			syme->source = line;
262 			break;
263 		}
264 	}
265 	pthread_mutex_unlock(&syme->source_lock);
266 }
267 
268 static void show_lines(struct source_line *queue, int count, int total)
269 {
270 	int i;
271 	struct source_line *line;
272 
273 	line = queue;
274 	for (i = 0; i < count; i++) {
275 		float pcnt = 100.0*(float)line->count[sym_counter]/(float)total;
276 
277 		printf("%8li %4.1f%%\t%s\n", line->count[sym_counter], pcnt, line->line);
278 		line = line->next;
279 	}
280 }
281 
282 #define TRACE_COUNT     3
283 
284 static void show_details(struct sym_entry *syme)
285 {
286 	struct symbol *symbol;
287 	struct source_line *line;
288 	struct source_line *line_queue = NULL;
289 	int displayed = 0;
290 	int line_queue_count = 0, total = 0, more = 0;
291 
292 	if (!syme)
293 		return;
294 
295 	if (!syme->source)
296 		lookup_sym_source(syme);
297 
298 	if (!syme->source)
299 		return;
300 
301 	symbol = (struct symbol *)(syme + 1);
302 	printf("Showing %s for %s\n", event_name(sym_counter), symbol->name);
303 	printf("  Events  Pcnt (>=%d%%)\n", sym_pcnt_filter);
304 
305 	pthread_mutex_lock(&syme->source_lock);
306 	line = syme->source;
307 	while (line) {
308 		total += line->count[sym_counter];
309 		line = line->next;
310 	}
311 
312 	line = syme->source;
313 	while (line) {
314 		float pcnt = 0.0;
315 
316 		if (!line_queue_count)
317 			line_queue = line;
318 		line_queue_count++;
319 
320 		if (line->count[sym_counter])
321 			pcnt = 100.0 * line->count[sym_counter] / (float)total;
322 		if (pcnt >= (float)sym_pcnt_filter) {
323 			if (displayed <= print_entries)
324 				show_lines(line_queue, line_queue_count, total);
325 			else more++;
326 			displayed += line_queue_count;
327 			line_queue_count = 0;
328 			line_queue = NULL;
329 		} else if (line_queue_count > TRACE_COUNT) {
330 			line_queue = line_queue->next;
331 			line_queue_count--;
332 		}
333 
334 		line->count[sym_counter] = zero ? 0 : line->count[sym_counter] * 7 / 8;
335 		line = line->next;
336 	}
337 	pthread_mutex_unlock(&syme->source_lock);
338 	if (more)
339 		printf("%d lines not displayed, maybe increase display entries [e]\n", more);
340 }
341 
342 /*
343  * Symbols will be added here in record_ip and will get out
344  * after decayed.
345  */
346 static LIST_HEAD(active_symbols);
347 static pthread_mutex_t active_symbols_lock = PTHREAD_MUTEX_INITIALIZER;
348 
349 /*
350  * Ordering weight: count-1 * count-2 * ... / count-n
351  */
352 static double sym_weight(const struct sym_entry *sym)
353 {
354 	double weight = sym->snap_count;
355 	int counter;
356 
357 	if (!display_weighted)
358 		return weight;
359 
360 	for (counter = 1; counter < nr_counters-1; counter++)
361 		weight *= sym->count[counter];
362 
363 	weight /= (sym->count[counter] + 1);
364 
365 	return weight;
366 }
367 
368 static long			samples;
369 static long			userspace_samples;
370 static const char		CONSOLE_CLEAR[] = "";
371 
372 static void __list_insert_active_sym(struct sym_entry *syme)
373 {
374 	list_add(&syme->node, &active_symbols);
375 }
376 
377 static void list_remove_active_sym(struct sym_entry *syme)
378 {
379 	pthread_mutex_lock(&active_symbols_lock);
380 	list_del_init(&syme->node);
381 	pthread_mutex_unlock(&active_symbols_lock);
382 }
383 
384 static void rb_insert_active_sym(struct rb_root *tree, struct sym_entry *se)
385 {
386 	struct rb_node **p = &tree->rb_node;
387 	struct rb_node *parent = NULL;
388 	struct sym_entry *iter;
389 
390 	while (*p != NULL) {
391 		parent = *p;
392 		iter = rb_entry(parent, struct sym_entry, rb_node);
393 
394 		if (se->weight > iter->weight)
395 			p = &(*p)->rb_left;
396 		else
397 			p = &(*p)->rb_right;
398 	}
399 
400 	rb_link_node(&se->rb_node, parent, p);
401 	rb_insert_color(&se->rb_node, tree);
402 }
403 
404 static void print_sym_table(void)
405 {
406 	int printed = 0, j;
407 	int counter, snap = !display_weighted ? sym_counter : 0;
408 	float samples_per_sec = samples/delay_secs;
409 	float ksamples_per_sec = (samples-userspace_samples)/delay_secs;
410 	float sum_ksamples = 0.0;
411 	struct sym_entry *syme, *n;
412 	struct rb_root tmp = RB_ROOT;
413 	struct rb_node *nd;
414 
415 	samples = userspace_samples = 0;
416 
417 	/* Sort the active symbols */
418 	pthread_mutex_lock(&active_symbols_lock);
419 	syme = list_entry(active_symbols.next, struct sym_entry, node);
420 	pthread_mutex_unlock(&active_symbols_lock);
421 
422 	list_for_each_entry_safe_from(syme, n, &active_symbols, node) {
423 		syme->snap_count = syme->count[snap];
424 		if (syme->snap_count != 0) {
425 			syme->weight = sym_weight(syme);
426 			rb_insert_active_sym(&tmp, syme);
427 			sum_ksamples += syme->snap_count;
428 
429 			for (j = 0; j < nr_counters; j++)
430 				syme->count[j] = zero ? 0 : syme->count[j] * 7 / 8;
431 		} else
432 			list_remove_active_sym(syme);
433 	}
434 
435 	puts(CONSOLE_CLEAR);
436 
437 	printf(
438 "------------------------------------------------------------------------------\n");
439 	printf( "   PerfTop:%8.0f irqs/sec  kernel:%4.1f%% [",
440 		samples_per_sec,
441 		100.0 - (100.0*((samples_per_sec-ksamples_per_sec)/samples_per_sec)));
442 
443 	if (nr_counters == 1 || !display_weighted) {
444 		printf("%Ld", (u64)attrs[0].sample_period);
445 		if (freq)
446 			printf("Hz ");
447 		else
448 			printf(" ");
449 	}
450 
451 	if (!display_weighted)
452 		printf("%s", event_name(sym_counter));
453 	else for (counter = 0; counter < nr_counters; counter++) {
454 		if (counter)
455 			printf("/");
456 
457 		printf("%s", event_name(counter));
458 	}
459 
460 	printf( "], ");
461 
462 	if (target_pid != -1)
463 		printf(" (target_pid: %d", target_pid);
464 	else
465 		printf(" (all");
466 
467 	if (profile_cpu != -1)
468 		printf(", cpu: %d)\n", profile_cpu);
469 	else {
470 		if (target_pid != -1)
471 			printf(")\n");
472 		else
473 			printf(", %d CPUs)\n", nr_cpus);
474 	}
475 
476 	printf("------------------------------------------------------------------------------\n\n");
477 
478 	if (sym_filter_entry) {
479 		show_details(sym_filter_entry);
480 		return;
481 	}
482 
483 	if (nr_counters == 1)
484 		printf("             samples    pcnt");
485 	else
486 		printf("   weight    samples    pcnt");
487 
488 	if (verbose)
489 		printf("         RIP       ");
490 	printf("   kernel function\n");
491 	printf("   %s    _______   _____",
492 	       nr_counters == 1 ? "      " : "______");
493 	if (verbose)
494 		printf("   ________________");
495 	printf("   _______________\n\n");
496 
497 	for (nd = rb_first(&tmp); nd; nd = rb_next(nd)) {
498 		struct symbol *sym;
499 		double pcnt;
500 
501 		syme = rb_entry(nd, struct sym_entry, rb_node);
502 		sym = (struct symbol *)(syme + 1);
503 
504 		if (++printed > print_entries || (int)syme->snap_count < count_filter)
505 			continue;
506 
507 		pcnt = 100.0 - (100.0 * ((sum_ksamples - syme->snap_count) /
508 					 sum_ksamples));
509 
510 		if (nr_counters == 1 || !display_weighted)
511 			printf("%20.2f - ", syme->weight);
512 		else
513 			printf("%9.1f %10ld - ", syme->weight, syme->snap_count);
514 
515 		percent_color_fprintf(stdout, "%4.1f%%", pcnt);
516 		if (verbose)
517 			printf(" - %016llx", sym->start);
518 		printf(" : %s", sym->name);
519 		if (sym->module)
520 			printf("\t[%s]", sym->module->name);
521 		printf("\n");
522 	}
523 }
524 
525 static void prompt_integer(int *target, const char *msg)
526 {
527 	char *buf = malloc(0), *p;
528 	size_t dummy = 0;
529 	int tmp;
530 
531 	fprintf(stdout, "\n%s: ", msg);
532 	if (getline(&buf, &dummy, stdin) < 0)
533 		return;
534 
535 	p = strchr(buf, '\n');
536 	if (p)
537 		*p = 0;
538 
539 	p = buf;
540 	while(*p) {
541 		if (!isdigit(*p))
542 			goto out_free;
543 		p++;
544 	}
545 	tmp = strtoul(buf, NULL, 10);
546 	*target = tmp;
547 out_free:
548 	free(buf);
549 }
550 
551 static void prompt_percent(int *target, const char *msg)
552 {
553 	int tmp = 0;
554 
555 	prompt_integer(&tmp, msg);
556 	if (tmp >= 0 && tmp <= 100)
557 		*target = tmp;
558 }
559 
560 static void prompt_symbol(struct sym_entry **target, const char *msg)
561 {
562 	char *buf = malloc(0), *p;
563 	struct sym_entry *syme = *target, *n, *found = NULL;
564 	size_t dummy = 0;
565 
566 	/* zero counters of active symbol */
567 	if (syme) {
568 		pthread_mutex_lock(&syme->source_lock);
569 		__zero_source_counters(syme);
570 		*target = NULL;
571 		pthread_mutex_unlock(&syme->source_lock);
572 	}
573 
574 	fprintf(stdout, "\n%s: ", msg);
575 	if (getline(&buf, &dummy, stdin) < 0)
576 		goto out_free;
577 
578 	p = strchr(buf, '\n');
579 	if (p)
580 		*p = 0;
581 
582 	pthread_mutex_lock(&active_symbols_lock);
583 	syme = list_entry(active_symbols.next, struct sym_entry, node);
584 	pthread_mutex_unlock(&active_symbols_lock);
585 
586 	list_for_each_entry_safe_from(syme, n, &active_symbols, node) {
587 		struct symbol *sym = (struct symbol *)(syme + 1);
588 
589 		if (!strcmp(buf, sym->name)) {
590 			found = syme;
591 			break;
592 		}
593 	}
594 
595 	if (!found) {
596 		fprintf(stderr, "Sorry, %s is not active.\n", sym_filter);
597 		sleep(1);
598 		return;
599 	} else
600 		parse_source(found);
601 
602 out_free:
603 	free(buf);
604 }
605 
606 static void print_mapped_keys(void)
607 {
608 	char *name = NULL;
609 
610 	if (sym_filter_entry) {
611 		struct symbol *sym = (struct symbol *)(sym_filter_entry+1);
612 		name = sym->name;
613 	}
614 
615 	fprintf(stdout, "\nMapped keys:\n");
616 	fprintf(stdout, "\t[d]     display refresh delay.             \t(%d)\n", delay_secs);
617 	fprintf(stdout, "\t[e]     display entries (lines).           \t(%d)\n", print_entries);
618 
619 	if (nr_counters > 1)
620 		fprintf(stdout, "\t[E]     active event counter.              \t(%s)\n", event_name(sym_counter));
621 
622 	fprintf(stdout, "\t[f]     profile display filter (count).    \t(%d)\n", count_filter);
623 
624 	if (vmlinux_name) {
625 		fprintf(stdout, "\t[F]     annotate display filter (percent). \t(%d%%)\n", sym_pcnt_filter);
626 		fprintf(stdout, "\t[s]     annotate symbol.                   \t(%s)\n", name?: "NULL");
627 		fprintf(stdout, "\t[S]     stop annotation.\n");
628 	}
629 
630 	if (nr_counters > 1)
631 		fprintf(stdout, "\t[w]     toggle display weighted/count[E]r. \t(%d)\n", display_weighted ? 1 : 0);
632 
633 	fprintf(stdout, "\t[z]     toggle sample zeroing.             \t(%d)\n", zero ? 1 : 0);
634 	fprintf(stdout, "\t[qQ]    quit.\n");
635 }
636 
637 static int key_mapped(int c)
638 {
639 	switch (c) {
640 		case 'd':
641 		case 'e':
642 		case 'f':
643 		case 'z':
644 		case 'q':
645 		case 'Q':
646 			return 1;
647 		case 'E':
648 		case 'w':
649 			return nr_counters > 1 ? 1 : 0;
650 		case 'F':
651 		case 's':
652 		case 'S':
653 			return vmlinux_name ? 1 : 0;
654 		default:
655 			break;
656 	}
657 
658 	return 0;
659 }
660 
661 static void handle_keypress(int c)
662 {
663 	if (!key_mapped(c)) {
664 		struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
665 		struct termios tc, save;
666 
667 		print_mapped_keys();
668 		fprintf(stdout, "\nEnter selection, or unmapped key to continue: ");
669 		fflush(stdout);
670 
671 		tcgetattr(0, &save);
672 		tc = save;
673 		tc.c_lflag &= ~(ICANON | ECHO);
674 		tc.c_cc[VMIN] = 0;
675 		tc.c_cc[VTIME] = 0;
676 		tcsetattr(0, TCSANOW, &tc);
677 
678 		poll(&stdin_poll, 1, -1);
679 		c = getc(stdin);
680 
681 		tcsetattr(0, TCSAFLUSH, &save);
682 		if (!key_mapped(c))
683 			return;
684 	}
685 
686 	switch (c) {
687 		case 'd':
688 			prompt_integer(&delay_secs, "Enter display delay");
689 			break;
690 		case 'e':
691 			prompt_integer(&print_entries, "Enter display entries (lines)");
692 			break;
693 		case 'E':
694 			if (nr_counters > 1) {
695 				int i;
696 
697 				fprintf(stderr, "\nAvailable events:");
698 				for (i = 0; i < nr_counters; i++)
699 					fprintf(stderr, "\n\t%d %s", i, event_name(i));
700 
701 				prompt_integer(&sym_counter, "Enter details event counter");
702 
703 				if (sym_counter >= nr_counters) {
704 					fprintf(stderr, "Sorry, no such event, using %s.\n", event_name(0));
705 					sym_counter = 0;
706 					sleep(1);
707 				}
708 			} else sym_counter = 0;
709 			break;
710 		case 'f':
711 			prompt_integer(&count_filter, "Enter display event count filter");
712 			break;
713 		case 'F':
714 			prompt_percent(&sym_pcnt_filter, "Enter details display event filter (percent)");
715 			break;
716 		case 'q':
717 		case 'Q':
718 			printf("exiting.\n");
719 			exit(0);
720 		case 's':
721 			prompt_symbol(&sym_filter_entry, "Enter details symbol");
722 			break;
723 		case 'S':
724 			if (!sym_filter_entry)
725 				break;
726 			else {
727 				struct sym_entry *syme = sym_filter_entry;
728 
729 				pthread_mutex_lock(&syme->source_lock);
730 				sym_filter_entry = NULL;
731 				__zero_source_counters(syme);
732 				pthread_mutex_unlock(&syme->source_lock);
733 			}
734 			break;
735 		case 'w':
736 			display_weighted = ~display_weighted;
737 			break;
738 		case 'z':
739 			zero = ~zero;
740 			break;
741 		default:
742 			break;
743 	}
744 }
745 
746 static void *display_thread(void *arg __used)
747 {
748 	struct pollfd stdin_poll = { .fd = 0, .events = POLLIN };
749 	struct termios tc, save;
750 	int delay_msecs, c;
751 
752 	tcgetattr(0, &save);
753 	tc = save;
754 	tc.c_lflag &= ~(ICANON | ECHO);
755 	tc.c_cc[VMIN] = 0;
756 	tc.c_cc[VTIME] = 0;
757 
758 repeat:
759 	delay_msecs = delay_secs * 1000;
760 	tcsetattr(0, TCSANOW, &tc);
761 	/* trash return*/
762 	getc(stdin);
763 
764 	do {
765 		print_sym_table();
766 	} while (!poll(&stdin_poll, 1, delay_msecs) == 1);
767 
768 	c = getc(stdin);
769 	tcsetattr(0, TCSAFLUSH, &save);
770 
771 	handle_keypress(c);
772 	goto repeat;
773 
774 	return NULL;
775 }
776 
777 /* Tag samples to be skipped. */
778 static const char *skip_symbols[] = {
779 	"default_idle",
780 	"cpu_idle",
781 	"enter_idle",
782 	"exit_idle",
783 	"mwait_idle",
784 	"mwait_idle_with_hints",
785 	"ppc64_runlatch_off",
786 	"pseries_dedicated_idle_sleep",
787 	NULL
788 };
789 
790 static int symbol_filter(struct dso *self, struct symbol *sym)
791 {
792 	struct sym_entry *syme;
793 	const char *name = sym->name;
794 	int i;
795 
796 	/*
797 	 * ppc64 uses function descriptors and appends a '.' to the
798 	 * start of every instruction address. Remove it.
799 	 */
800 	if (name[0] == '.')
801 		name++;
802 
803 	if (!strcmp(name, "_text") ||
804 	    !strcmp(name, "_etext") ||
805 	    !strcmp(name, "_sinittext") ||
806 	    !strncmp("init_module", name, 11) ||
807 	    !strncmp("cleanup_module", name, 14) ||
808 	    strstr(name, "_text_start") ||
809 	    strstr(name, "_text_end"))
810 		return 1;
811 
812 	syme = dso__sym_priv(self, sym);
813 	pthread_mutex_init(&syme->source_lock, NULL);
814 	if (!sym_filter_entry && sym_filter && !strcmp(name, sym_filter))
815 		sym_filter_entry = syme;
816 
817 	for (i = 0; skip_symbols[i]; i++) {
818 		if (!strcmp(skip_symbols[i], name)) {
819 			syme->skip = 1;
820 			break;
821 		}
822 	}
823 
824 	return 0;
825 }
826 
827 static int parse_symbols(void)
828 {
829 	struct rb_node *node;
830 	struct symbol  *sym;
831 	int use_modules = vmlinux_name ? 1 : 0;
832 
833 	kernel_dso = dso__new("[kernel]", sizeof(struct sym_entry));
834 	if (kernel_dso == NULL)
835 		return -1;
836 
837 	if (dso__load_kernel(kernel_dso, vmlinux_name, symbol_filter, verbose, use_modules) <= 0)
838 		goto out_delete_dso;
839 
840 	node = rb_first(&kernel_dso->syms);
841 	sym = rb_entry(node, struct symbol, rb_node);
842 	min_ip = sym->start;
843 
844 	node = rb_last(&kernel_dso->syms);
845 	sym = rb_entry(node, struct symbol, rb_node);
846 	max_ip = sym->end;
847 
848 	if (dump_symtab)
849 		dso__fprintf(kernel_dso, stderr);
850 
851 	return 0;
852 
853 out_delete_dso:
854 	dso__delete(kernel_dso);
855 	kernel_dso = NULL;
856 	return -1;
857 }
858 
859 /*
860  * Binary search in the histogram table and record the hit:
861  */
862 static void record_ip(u64 ip, int counter)
863 {
864 	struct symbol *sym = dso__find_symbol(kernel_dso, ip);
865 
866 	if (sym != NULL) {
867 		struct sym_entry *syme = dso__sym_priv(kernel_dso, sym);
868 
869 		if (!syme->skip) {
870 			syme->count[counter]++;
871 			record_precise_ip(syme, counter, ip);
872 			pthread_mutex_lock(&active_symbols_lock);
873 			if (list_empty(&syme->node) || !syme->node.next)
874 				__list_insert_active_sym(syme);
875 			pthread_mutex_unlock(&active_symbols_lock);
876 			return;
877 		}
878 	}
879 
880 	samples--;
881 }
882 
883 static void process_event(u64 ip, int counter, int user)
884 {
885 	samples++;
886 
887 	if (user) {
888 		userspace_samples++;
889 		return;
890 	}
891 
892 	record_ip(ip, counter);
893 }
894 
895 struct mmap_data {
896 	int			counter;
897 	void			*base;
898 	int			mask;
899 	unsigned int		prev;
900 };
901 
902 static unsigned int mmap_read_head(struct mmap_data *md)
903 {
904 	struct perf_event_mmap_page *pc = md->base;
905 	int head;
906 
907 	head = pc->data_head;
908 	rmb();
909 
910 	return head;
911 }
912 
913 struct timeval last_read, this_read;
914 
915 static void mmap_read_counter(struct mmap_data *md)
916 {
917 	unsigned int head = mmap_read_head(md);
918 	unsigned int old = md->prev;
919 	unsigned char *data = md->base + page_size;
920 	int diff;
921 
922 	gettimeofday(&this_read, NULL);
923 
924 	/*
925 	 * If we're further behind than half the buffer, there's a chance
926 	 * the writer will bite our tail and mess up the samples under us.
927 	 *
928 	 * If we somehow ended up ahead of the head, we got messed up.
929 	 *
930 	 * In either case, truncate and restart at head.
931 	 */
932 	diff = head - old;
933 	if (diff > md->mask / 2 || diff < 0) {
934 		struct timeval iv;
935 		unsigned long msecs;
936 
937 		timersub(&this_read, &last_read, &iv);
938 		msecs = iv.tv_sec*1000 + iv.tv_usec/1000;
939 
940 		fprintf(stderr, "WARNING: failed to keep up with mmap data."
941 				"  Last read %lu msecs ago.\n", msecs);
942 
943 		/*
944 		 * head points to a known good entry, start there.
945 		 */
946 		old = head;
947 	}
948 
949 	last_read = this_read;
950 
951 	for (; old != head;) {
952 		event_t *event = (event_t *)&data[old & md->mask];
953 
954 		event_t event_copy;
955 
956 		size_t size = event->header.size;
957 
958 		/*
959 		 * Event straddles the mmap boundary -- header should always
960 		 * be inside due to u64 alignment of output.
961 		 */
962 		if ((old & md->mask) + size != ((old + size) & md->mask)) {
963 			unsigned int offset = old;
964 			unsigned int len = min(sizeof(*event), size), cpy;
965 			void *dst = &event_copy;
966 
967 			do {
968 				cpy = min(md->mask + 1 - (offset & md->mask), len);
969 				memcpy(dst, &data[offset & md->mask], cpy);
970 				offset += cpy;
971 				dst += cpy;
972 				len -= cpy;
973 			} while (len);
974 
975 			event = &event_copy;
976 		}
977 
978 		old += size;
979 
980 		if (event->header.type == PERF_RECORD_SAMPLE) {
981 			int user =
982 	(event->header.misc & PERF_RECORD_MISC_CPUMODE_MASK) == PERF_RECORD_MISC_USER;
983 			process_event(event->ip.ip, md->counter, user);
984 		}
985 	}
986 
987 	md->prev = old;
988 }
989 
990 static struct pollfd event_array[MAX_NR_CPUS * MAX_COUNTERS];
991 static struct mmap_data mmap_array[MAX_NR_CPUS][MAX_COUNTERS];
992 
993 static void mmap_read(void)
994 {
995 	int i, counter;
996 
997 	for (i = 0; i < nr_cpus; i++) {
998 		for (counter = 0; counter < nr_counters; counter++)
999 			mmap_read_counter(&mmap_array[i][counter]);
1000 	}
1001 }
1002 
1003 int nr_poll;
1004 int group_fd;
1005 
1006 static void start_counter(int i, int counter)
1007 {
1008 	struct perf_event_attr *attr;
1009 	int cpu;
1010 
1011 	cpu = profile_cpu;
1012 	if (target_pid == -1 && profile_cpu == -1)
1013 		cpu = i;
1014 
1015 	attr = attrs + counter;
1016 
1017 	attr->sample_type	= PERF_SAMPLE_IP | PERF_SAMPLE_TID;
1018 	attr->freq		= freq;
1019 	attr->inherit		= (cpu < 0) && inherit;
1020 
1021 try_again:
1022 	fd[i][counter] = sys_perf_event_open(attr, target_pid, cpu, group_fd, 0);
1023 
1024 	if (fd[i][counter] < 0) {
1025 		int err = errno;
1026 
1027 		if (err == EPERM)
1028 			die("No permission - are you root?\n");
1029 		/*
1030 		 * If it's cycles then fall back to hrtimer
1031 		 * based cpu-clock-tick sw counter, which
1032 		 * is always available even if no PMU support:
1033 		 */
1034 		if (attr->type == PERF_TYPE_HARDWARE
1035 			&& attr->config == PERF_COUNT_HW_CPU_CYCLES) {
1036 
1037 			if (verbose)
1038 				warning(" ... trying to fall back to cpu-clock-ticks\n");
1039 
1040 			attr->type = PERF_TYPE_SOFTWARE;
1041 			attr->config = PERF_COUNT_SW_CPU_CLOCK;
1042 			goto try_again;
1043 		}
1044 		printf("\n");
1045 		error("perfcounter syscall returned with %d (%s)\n",
1046 			fd[i][counter], strerror(err));
1047 		die("No CONFIG_PERF_EVENTS=y kernel support configured?\n");
1048 		exit(-1);
1049 	}
1050 	assert(fd[i][counter] >= 0);
1051 	fcntl(fd[i][counter], F_SETFL, O_NONBLOCK);
1052 
1053 	/*
1054 	 * First counter acts as the group leader:
1055 	 */
1056 	if (group && group_fd == -1)
1057 		group_fd = fd[i][counter];
1058 
1059 	event_array[nr_poll].fd = fd[i][counter];
1060 	event_array[nr_poll].events = POLLIN;
1061 	nr_poll++;
1062 
1063 	mmap_array[i][counter].counter = counter;
1064 	mmap_array[i][counter].prev = 0;
1065 	mmap_array[i][counter].mask = mmap_pages*page_size - 1;
1066 	mmap_array[i][counter].base = mmap(NULL, (mmap_pages+1)*page_size,
1067 			PROT_READ, MAP_SHARED, fd[i][counter], 0);
1068 	if (mmap_array[i][counter].base == MAP_FAILED)
1069 		die("failed to mmap with %d (%s)\n", errno, strerror(errno));
1070 }
1071 
1072 static int __cmd_top(void)
1073 {
1074 	pthread_t thread;
1075 	int i, counter;
1076 	int ret;
1077 
1078 	for (i = 0; i < nr_cpus; i++) {
1079 		group_fd = -1;
1080 		for (counter = 0; counter < nr_counters; counter++)
1081 			start_counter(i, counter);
1082 	}
1083 
1084 	/* Wait for a minimal set of events before starting the snapshot */
1085 	poll(event_array, nr_poll, 100);
1086 
1087 	mmap_read();
1088 
1089 	if (pthread_create(&thread, NULL, display_thread, NULL)) {
1090 		printf("Could not create display thread.\n");
1091 		exit(-1);
1092 	}
1093 
1094 	if (realtime_prio) {
1095 		struct sched_param param;
1096 
1097 		param.sched_priority = realtime_prio;
1098 		if (sched_setscheduler(0, SCHED_FIFO, &param)) {
1099 			printf("Could not set realtime priority.\n");
1100 			exit(-1);
1101 		}
1102 	}
1103 
1104 	while (1) {
1105 		int hits = samples;
1106 
1107 		mmap_read();
1108 
1109 		if (hits == samples)
1110 			ret = poll(event_array, nr_poll, 100);
1111 	}
1112 
1113 	return 0;
1114 }
1115 
1116 static const char * const top_usage[] = {
1117 	"perf top [<options>]",
1118 	NULL
1119 };
1120 
1121 static const struct option options[] = {
1122 	OPT_CALLBACK('e', "event", NULL, "event",
1123 		     "event selector. use 'perf list' to list available events",
1124 		     parse_events),
1125 	OPT_INTEGER('c', "count", &default_interval,
1126 		    "event period to sample"),
1127 	OPT_INTEGER('p', "pid", &target_pid,
1128 		    "profile events on existing pid"),
1129 	OPT_BOOLEAN('a', "all-cpus", &system_wide,
1130 			    "system-wide collection from all CPUs"),
1131 	OPT_INTEGER('C', "CPU", &profile_cpu,
1132 		    "CPU to profile on"),
1133 	OPT_STRING('k', "vmlinux", &vmlinux_name, "file", "vmlinux pathname"),
1134 	OPT_INTEGER('m', "mmap-pages", &mmap_pages,
1135 		    "number of mmap data pages"),
1136 	OPT_INTEGER('r', "realtime", &realtime_prio,
1137 		    "collect data with this RT SCHED_FIFO priority"),
1138 	OPT_INTEGER('d', "delay", &delay_secs,
1139 		    "number of seconds to delay between refreshes"),
1140 	OPT_BOOLEAN('D', "dump-symtab", &dump_symtab,
1141 			    "dump the symbol table used for profiling"),
1142 	OPT_INTEGER('f', "count-filter", &count_filter,
1143 		    "only display functions with more events than this"),
1144 	OPT_BOOLEAN('g', "group", &group,
1145 			    "put the counters into a counter group"),
1146 	OPT_BOOLEAN('i', "inherit", &inherit,
1147 		    "child tasks inherit counters"),
1148 	OPT_STRING('s', "sym-annotate", &sym_filter, "symbol name",
1149 		    "symbol to annotate - requires -k option"),
1150 	OPT_BOOLEAN('z', "zero", &zero,
1151 		    "zero history across updates"),
1152 	OPT_INTEGER('F', "freq", &freq,
1153 		    "profile at this frequency"),
1154 	OPT_INTEGER('E', "entries", &print_entries,
1155 		    "display this many functions"),
1156 	OPT_BOOLEAN('v', "verbose", &verbose,
1157 		    "be more verbose (show counter open errors, etc)"),
1158 	OPT_END()
1159 };
1160 
1161 int cmd_top(int argc, const char **argv, const char *prefix __used)
1162 {
1163 	int counter;
1164 
1165 	symbol__init();
1166 
1167 	page_size = sysconf(_SC_PAGE_SIZE);
1168 
1169 	argc = parse_options(argc, argv, options, top_usage, 0);
1170 	if (argc)
1171 		usage_with_options(top_usage, options);
1172 
1173 	if (freq) {
1174 		default_interval = freq;
1175 		freq = 1;
1176 	}
1177 
1178 	/* CPU and PID are mutually exclusive */
1179 	if (target_pid != -1 && profile_cpu != -1) {
1180 		printf("WARNING: PID switch overriding CPU\n");
1181 		sleep(1);
1182 		profile_cpu = -1;
1183 	}
1184 
1185 	if (!nr_counters)
1186 		nr_counters = 1;
1187 
1188 	if (delay_secs < 1)
1189 		delay_secs = 1;
1190 
1191 	parse_symbols();
1192 	parse_source(sym_filter_entry);
1193 
1194 	/*
1195 	 * Fill in the ones not specifically initialized via -c:
1196 	 */
1197 	for (counter = 0; counter < nr_counters; counter++) {
1198 		if (attrs[counter].sample_period)
1199 			continue;
1200 
1201 		attrs[counter].sample_period = default_interval;
1202 	}
1203 
1204 	nr_cpus = sysconf(_SC_NPROCESSORS_ONLN);
1205 	assert(nr_cpus <= MAX_NR_CPUS);
1206 	assert(nr_cpus >= 0);
1207 
1208 	if (target_pid != -1 || profile_cpu != -1)
1209 		nr_cpus = 1;
1210 
1211 	return __cmd_top();
1212 }
1213