xref: /linux/tools/perf/builtin-sched.c (revision ca55b2fef3a9373fcfc30f82fd26bc7fccbda732)
1 #include "builtin.h"
2 #include "perf.h"
3 
4 #include "util/util.h"
5 #include "util/evlist.h"
6 #include "util/cache.h"
7 #include "util/evsel.h"
8 #include "util/symbol.h"
9 #include "util/thread.h"
10 #include "util/header.h"
11 #include "util/session.h"
12 #include "util/tool.h"
13 #include "util/cloexec.h"
14 
15 #include "util/parse-options.h"
16 #include "util/trace-event.h"
17 
18 #include "util/debug.h"
19 
20 #include <sys/prctl.h>
21 #include <sys/resource.h>
22 
23 #include <semaphore.h>
24 #include <pthread.h>
25 #include <math.h>
26 #include <api/fs/fs.h>
27 
28 #define PR_SET_NAME		15               /* Set process name */
29 #define MAX_CPUS		4096
30 #define COMM_LEN		20
31 #define SYM_LEN			129
32 #define MAX_PID			1024000
33 
34 struct sched_atom;
35 
36 struct task_desc {
37 	unsigned long		nr;
38 	unsigned long		pid;
39 	char			comm[COMM_LEN];
40 
41 	unsigned long		nr_events;
42 	unsigned long		curr_event;
43 	struct sched_atom	**atoms;
44 
45 	pthread_t		thread;
46 	sem_t			sleep_sem;
47 
48 	sem_t			ready_for_work;
49 	sem_t			work_done_sem;
50 
51 	u64			cpu_usage;
52 };
53 
54 enum sched_event_type {
55 	SCHED_EVENT_RUN,
56 	SCHED_EVENT_SLEEP,
57 	SCHED_EVENT_WAKEUP,
58 	SCHED_EVENT_MIGRATION,
59 };
60 
61 struct sched_atom {
62 	enum sched_event_type	type;
63 	int			specific_wait;
64 	u64			timestamp;
65 	u64			duration;
66 	unsigned long		nr;
67 	sem_t			*wait_sem;
68 	struct task_desc	*wakee;
69 };
70 
71 #define TASK_STATE_TO_CHAR_STR "RSDTtZXxKWP"
72 
73 enum thread_state {
74 	THREAD_SLEEPING = 0,
75 	THREAD_WAIT_CPU,
76 	THREAD_SCHED_IN,
77 	THREAD_IGNORE
78 };
79 
80 struct work_atom {
81 	struct list_head	list;
82 	enum thread_state	state;
83 	u64			sched_out_time;
84 	u64			wake_up_time;
85 	u64			sched_in_time;
86 	u64			runtime;
87 };
88 
89 struct work_atoms {
90 	struct list_head	work_list;
91 	struct thread		*thread;
92 	struct rb_node		node;
93 	u64			max_lat;
94 	u64			max_lat_at;
95 	u64			total_lat;
96 	u64			nb_atoms;
97 	u64			total_runtime;
98 	int			num_merged;
99 };
100 
101 typedef int (*sort_fn_t)(struct work_atoms *, struct work_atoms *);
102 
103 struct perf_sched;
104 
105 struct trace_sched_handler {
106 	int (*switch_event)(struct perf_sched *sched, struct perf_evsel *evsel,
107 			    struct perf_sample *sample, struct machine *machine);
108 
109 	int (*runtime_event)(struct perf_sched *sched, struct perf_evsel *evsel,
110 			     struct perf_sample *sample, struct machine *machine);
111 
112 	int (*wakeup_event)(struct perf_sched *sched, struct perf_evsel *evsel,
113 			    struct perf_sample *sample, struct machine *machine);
114 
115 	/* PERF_RECORD_FORK event, not sched_process_fork tracepoint */
116 	int (*fork_event)(struct perf_sched *sched, union perf_event *event,
117 			  struct machine *machine);
118 
119 	int (*migrate_task_event)(struct perf_sched *sched,
120 				  struct perf_evsel *evsel,
121 				  struct perf_sample *sample,
122 				  struct machine *machine);
123 };
124 
125 struct perf_sched {
126 	struct perf_tool tool;
127 	const char	 *sort_order;
128 	unsigned long	 nr_tasks;
129 	struct task_desc **pid_to_task;
130 	struct task_desc **tasks;
131 	const struct trace_sched_handler *tp_handler;
132 	pthread_mutex_t	 start_work_mutex;
133 	pthread_mutex_t	 work_done_wait_mutex;
134 	int		 profile_cpu;
135 /*
136  * Track the current task - that way we can know whether there's any
137  * weird events, such as a task being switched away that is not current.
138  */
139 	int		 max_cpu;
140 	u32		 curr_pid[MAX_CPUS];
141 	struct thread	 *curr_thread[MAX_CPUS];
142 	char		 next_shortname1;
143 	char		 next_shortname2;
144 	unsigned int	 replay_repeat;
145 	unsigned long	 nr_run_events;
146 	unsigned long	 nr_sleep_events;
147 	unsigned long	 nr_wakeup_events;
148 	unsigned long	 nr_sleep_corrections;
149 	unsigned long	 nr_run_events_optimized;
150 	unsigned long	 targetless_wakeups;
151 	unsigned long	 multitarget_wakeups;
152 	unsigned long	 nr_runs;
153 	unsigned long	 nr_timestamps;
154 	unsigned long	 nr_unordered_timestamps;
155 	unsigned long	 nr_context_switch_bugs;
156 	unsigned long	 nr_events;
157 	unsigned long	 nr_lost_chunks;
158 	unsigned long	 nr_lost_events;
159 	u64		 run_measurement_overhead;
160 	u64		 sleep_measurement_overhead;
161 	u64		 start_time;
162 	u64		 cpu_usage;
163 	u64		 runavg_cpu_usage;
164 	u64		 parent_cpu_usage;
165 	u64		 runavg_parent_cpu_usage;
166 	u64		 sum_runtime;
167 	u64		 sum_fluct;
168 	u64		 run_avg;
169 	u64		 all_runtime;
170 	u64		 all_count;
171 	u64		 cpu_last_switched[MAX_CPUS];
172 	struct rb_root	 atom_root, sorted_atom_root, merged_atom_root;
173 	struct list_head sort_list, cmp_pid;
174 	bool force;
175 	bool skip_merge;
176 };
177 
178 static u64 get_nsecs(void)
179 {
180 	struct timespec ts;
181 
182 	clock_gettime(CLOCK_MONOTONIC, &ts);
183 
184 	return ts.tv_sec * 1000000000ULL + ts.tv_nsec;
185 }
186 
187 static void burn_nsecs(struct perf_sched *sched, u64 nsecs)
188 {
189 	u64 T0 = get_nsecs(), T1;
190 
191 	do {
192 		T1 = get_nsecs();
193 	} while (T1 + sched->run_measurement_overhead < T0 + nsecs);
194 }
195 
196 static void sleep_nsecs(u64 nsecs)
197 {
198 	struct timespec ts;
199 
200 	ts.tv_nsec = nsecs % 999999999;
201 	ts.tv_sec = nsecs / 999999999;
202 
203 	nanosleep(&ts, NULL);
204 }
205 
206 static void calibrate_run_measurement_overhead(struct perf_sched *sched)
207 {
208 	u64 T0, T1, delta, min_delta = 1000000000ULL;
209 	int i;
210 
211 	for (i = 0; i < 10; i++) {
212 		T0 = get_nsecs();
213 		burn_nsecs(sched, 0);
214 		T1 = get_nsecs();
215 		delta = T1-T0;
216 		min_delta = min(min_delta, delta);
217 	}
218 	sched->run_measurement_overhead = min_delta;
219 
220 	printf("run measurement overhead: %" PRIu64 " nsecs\n", min_delta);
221 }
222 
223 static void calibrate_sleep_measurement_overhead(struct perf_sched *sched)
224 {
225 	u64 T0, T1, delta, min_delta = 1000000000ULL;
226 	int i;
227 
228 	for (i = 0; i < 10; i++) {
229 		T0 = get_nsecs();
230 		sleep_nsecs(10000);
231 		T1 = get_nsecs();
232 		delta = T1-T0;
233 		min_delta = min(min_delta, delta);
234 	}
235 	min_delta -= 10000;
236 	sched->sleep_measurement_overhead = min_delta;
237 
238 	printf("sleep measurement overhead: %" PRIu64 " nsecs\n", min_delta);
239 }
240 
241 static struct sched_atom *
242 get_new_event(struct task_desc *task, u64 timestamp)
243 {
244 	struct sched_atom *event = zalloc(sizeof(*event));
245 	unsigned long idx = task->nr_events;
246 	size_t size;
247 
248 	event->timestamp = timestamp;
249 	event->nr = idx;
250 
251 	task->nr_events++;
252 	size = sizeof(struct sched_atom *) * task->nr_events;
253 	task->atoms = realloc(task->atoms, size);
254 	BUG_ON(!task->atoms);
255 
256 	task->atoms[idx] = event;
257 
258 	return event;
259 }
260 
261 static struct sched_atom *last_event(struct task_desc *task)
262 {
263 	if (!task->nr_events)
264 		return NULL;
265 
266 	return task->atoms[task->nr_events - 1];
267 }
268 
269 static void add_sched_event_run(struct perf_sched *sched, struct task_desc *task,
270 				u64 timestamp, u64 duration)
271 {
272 	struct sched_atom *event, *curr_event = last_event(task);
273 
274 	/*
275 	 * optimize an existing RUN event by merging this one
276 	 * to it:
277 	 */
278 	if (curr_event && curr_event->type == SCHED_EVENT_RUN) {
279 		sched->nr_run_events_optimized++;
280 		curr_event->duration += duration;
281 		return;
282 	}
283 
284 	event = get_new_event(task, timestamp);
285 
286 	event->type = SCHED_EVENT_RUN;
287 	event->duration = duration;
288 
289 	sched->nr_run_events++;
290 }
291 
292 static void add_sched_event_wakeup(struct perf_sched *sched, struct task_desc *task,
293 				   u64 timestamp, struct task_desc *wakee)
294 {
295 	struct sched_atom *event, *wakee_event;
296 
297 	event = get_new_event(task, timestamp);
298 	event->type = SCHED_EVENT_WAKEUP;
299 	event->wakee = wakee;
300 
301 	wakee_event = last_event(wakee);
302 	if (!wakee_event || wakee_event->type != SCHED_EVENT_SLEEP) {
303 		sched->targetless_wakeups++;
304 		return;
305 	}
306 	if (wakee_event->wait_sem) {
307 		sched->multitarget_wakeups++;
308 		return;
309 	}
310 
311 	wakee_event->wait_sem = zalloc(sizeof(*wakee_event->wait_sem));
312 	sem_init(wakee_event->wait_sem, 0, 0);
313 	wakee_event->specific_wait = 1;
314 	event->wait_sem = wakee_event->wait_sem;
315 
316 	sched->nr_wakeup_events++;
317 }
318 
319 static void add_sched_event_sleep(struct perf_sched *sched, struct task_desc *task,
320 				  u64 timestamp, u64 task_state __maybe_unused)
321 {
322 	struct sched_atom *event = get_new_event(task, timestamp);
323 
324 	event->type = SCHED_EVENT_SLEEP;
325 
326 	sched->nr_sleep_events++;
327 }
328 
329 static struct task_desc *register_pid(struct perf_sched *sched,
330 				      unsigned long pid, const char *comm)
331 {
332 	struct task_desc *task;
333 	static int pid_max;
334 
335 	if (sched->pid_to_task == NULL) {
336 		if (sysctl__read_int("kernel/pid_max", &pid_max) < 0)
337 			pid_max = MAX_PID;
338 		BUG_ON((sched->pid_to_task = calloc(pid_max, sizeof(struct task_desc *))) == NULL);
339 	}
340 	if (pid >= (unsigned long)pid_max) {
341 		BUG_ON((sched->pid_to_task = realloc(sched->pid_to_task, (pid + 1) *
342 			sizeof(struct task_desc *))) == NULL);
343 		while (pid >= (unsigned long)pid_max)
344 			sched->pid_to_task[pid_max++] = NULL;
345 	}
346 
347 	task = sched->pid_to_task[pid];
348 
349 	if (task)
350 		return task;
351 
352 	task = zalloc(sizeof(*task));
353 	task->pid = pid;
354 	task->nr = sched->nr_tasks;
355 	strcpy(task->comm, comm);
356 	/*
357 	 * every task starts in sleeping state - this gets ignored
358 	 * if there's no wakeup pointing to this sleep state:
359 	 */
360 	add_sched_event_sleep(sched, task, 0, 0);
361 
362 	sched->pid_to_task[pid] = task;
363 	sched->nr_tasks++;
364 	sched->tasks = realloc(sched->tasks, sched->nr_tasks * sizeof(struct task_desc *));
365 	BUG_ON(!sched->tasks);
366 	sched->tasks[task->nr] = task;
367 
368 	if (verbose)
369 		printf("registered task #%ld, PID %ld (%s)\n", sched->nr_tasks, pid, comm);
370 
371 	return task;
372 }
373 
374 
375 static void print_task_traces(struct perf_sched *sched)
376 {
377 	struct task_desc *task;
378 	unsigned long i;
379 
380 	for (i = 0; i < sched->nr_tasks; i++) {
381 		task = sched->tasks[i];
382 		printf("task %6ld (%20s:%10ld), nr_events: %ld\n",
383 			task->nr, task->comm, task->pid, task->nr_events);
384 	}
385 }
386 
387 static void add_cross_task_wakeups(struct perf_sched *sched)
388 {
389 	struct task_desc *task1, *task2;
390 	unsigned long i, j;
391 
392 	for (i = 0; i < sched->nr_tasks; i++) {
393 		task1 = sched->tasks[i];
394 		j = i + 1;
395 		if (j == sched->nr_tasks)
396 			j = 0;
397 		task2 = sched->tasks[j];
398 		add_sched_event_wakeup(sched, task1, 0, task2);
399 	}
400 }
401 
402 static void perf_sched__process_event(struct perf_sched *sched,
403 				      struct sched_atom *atom)
404 {
405 	int ret = 0;
406 
407 	switch (atom->type) {
408 		case SCHED_EVENT_RUN:
409 			burn_nsecs(sched, atom->duration);
410 			break;
411 		case SCHED_EVENT_SLEEP:
412 			if (atom->wait_sem)
413 				ret = sem_wait(atom->wait_sem);
414 			BUG_ON(ret);
415 			break;
416 		case SCHED_EVENT_WAKEUP:
417 			if (atom->wait_sem)
418 				ret = sem_post(atom->wait_sem);
419 			BUG_ON(ret);
420 			break;
421 		case SCHED_EVENT_MIGRATION:
422 			break;
423 		default:
424 			BUG_ON(1);
425 	}
426 }
427 
428 static u64 get_cpu_usage_nsec_parent(void)
429 {
430 	struct rusage ru;
431 	u64 sum;
432 	int err;
433 
434 	err = getrusage(RUSAGE_SELF, &ru);
435 	BUG_ON(err);
436 
437 	sum =  ru.ru_utime.tv_sec*1e9 + ru.ru_utime.tv_usec*1e3;
438 	sum += ru.ru_stime.tv_sec*1e9 + ru.ru_stime.tv_usec*1e3;
439 
440 	return sum;
441 }
442 
443 static int self_open_counters(struct perf_sched *sched, unsigned long cur_task)
444 {
445 	struct perf_event_attr attr;
446 	char sbuf[STRERR_BUFSIZE], info[STRERR_BUFSIZE];
447 	int fd;
448 	struct rlimit limit;
449 	bool need_privilege = false;
450 
451 	memset(&attr, 0, sizeof(attr));
452 
453 	attr.type = PERF_TYPE_SOFTWARE;
454 	attr.config = PERF_COUNT_SW_TASK_CLOCK;
455 
456 force_again:
457 	fd = sys_perf_event_open(&attr, 0, -1, -1,
458 				 perf_event_open_cloexec_flag());
459 
460 	if (fd < 0) {
461 		if (errno == EMFILE) {
462 			if (sched->force) {
463 				BUG_ON(getrlimit(RLIMIT_NOFILE, &limit) == -1);
464 				limit.rlim_cur += sched->nr_tasks - cur_task;
465 				if (limit.rlim_cur > limit.rlim_max) {
466 					limit.rlim_max = limit.rlim_cur;
467 					need_privilege = true;
468 				}
469 				if (setrlimit(RLIMIT_NOFILE, &limit) == -1) {
470 					if (need_privilege && errno == EPERM)
471 						strcpy(info, "Need privilege\n");
472 				} else
473 					goto force_again;
474 			} else
475 				strcpy(info, "Have a try with -f option\n");
476 		}
477 		pr_err("Error: sys_perf_event_open() syscall returned "
478 		       "with %d (%s)\n%s", fd,
479 		       strerror_r(errno, sbuf, sizeof(sbuf)), info);
480 		exit(EXIT_FAILURE);
481 	}
482 	return fd;
483 }
484 
485 static u64 get_cpu_usage_nsec_self(int fd)
486 {
487 	u64 runtime;
488 	int ret;
489 
490 	ret = read(fd, &runtime, sizeof(runtime));
491 	BUG_ON(ret != sizeof(runtime));
492 
493 	return runtime;
494 }
495 
496 struct sched_thread_parms {
497 	struct task_desc  *task;
498 	struct perf_sched *sched;
499 	int fd;
500 };
501 
502 static void *thread_func(void *ctx)
503 {
504 	struct sched_thread_parms *parms = ctx;
505 	struct task_desc *this_task = parms->task;
506 	struct perf_sched *sched = parms->sched;
507 	u64 cpu_usage_0, cpu_usage_1;
508 	unsigned long i, ret;
509 	char comm2[22];
510 	int fd = parms->fd;
511 
512 	zfree(&parms);
513 
514 	sprintf(comm2, ":%s", this_task->comm);
515 	prctl(PR_SET_NAME, comm2);
516 	if (fd < 0)
517 		return NULL;
518 again:
519 	ret = sem_post(&this_task->ready_for_work);
520 	BUG_ON(ret);
521 	ret = pthread_mutex_lock(&sched->start_work_mutex);
522 	BUG_ON(ret);
523 	ret = pthread_mutex_unlock(&sched->start_work_mutex);
524 	BUG_ON(ret);
525 
526 	cpu_usage_0 = get_cpu_usage_nsec_self(fd);
527 
528 	for (i = 0; i < this_task->nr_events; i++) {
529 		this_task->curr_event = i;
530 		perf_sched__process_event(sched, this_task->atoms[i]);
531 	}
532 
533 	cpu_usage_1 = get_cpu_usage_nsec_self(fd);
534 	this_task->cpu_usage = cpu_usage_1 - cpu_usage_0;
535 	ret = sem_post(&this_task->work_done_sem);
536 	BUG_ON(ret);
537 
538 	ret = pthread_mutex_lock(&sched->work_done_wait_mutex);
539 	BUG_ON(ret);
540 	ret = pthread_mutex_unlock(&sched->work_done_wait_mutex);
541 	BUG_ON(ret);
542 
543 	goto again;
544 }
545 
546 static void create_tasks(struct perf_sched *sched)
547 {
548 	struct task_desc *task;
549 	pthread_attr_t attr;
550 	unsigned long i;
551 	int err;
552 
553 	err = pthread_attr_init(&attr);
554 	BUG_ON(err);
555 	err = pthread_attr_setstacksize(&attr,
556 			(size_t) max(16 * 1024, PTHREAD_STACK_MIN));
557 	BUG_ON(err);
558 	err = pthread_mutex_lock(&sched->start_work_mutex);
559 	BUG_ON(err);
560 	err = pthread_mutex_lock(&sched->work_done_wait_mutex);
561 	BUG_ON(err);
562 	for (i = 0; i < sched->nr_tasks; i++) {
563 		struct sched_thread_parms *parms = malloc(sizeof(*parms));
564 		BUG_ON(parms == NULL);
565 		parms->task = task = sched->tasks[i];
566 		parms->sched = sched;
567 		parms->fd = self_open_counters(sched, i);
568 		sem_init(&task->sleep_sem, 0, 0);
569 		sem_init(&task->ready_for_work, 0, 0);
570 		sem_init(&task->work_done_sem, 0, 0);
571 		task->curr_event = 0;
572 		err = pthread_create(&task->thread, &attr, thread_func, parms);
573 		BUG_ON(err);
574 	}
575 }
576 
577 static void wait_for_tasks(struct perf_sched *sched)
578 {
579 	u64 cpu_usage_0, cpu_usage_1;
580 	struct task_desc *task;
581 	unsigned long i, ret;
582 
583 	sched->start_time = get_nsecs();
584 	sched->cpu_usage = 0;
585 	pthread_mutex_unlock(&sched->work_done_wait_mutex);
586 
587 	for (i = 0; i < sched->nr_tasks; i++) {
588 		task = sched->tasks[i];
589 		ret = sem_wait(&task->ready_for_work);
590 		BUG_ON(ret);
591 		sem_init(&task->ready_for_work, 0, 0);
592 	}
593 	ret = pthread_mutex_lock(&sched->work_done_wait_mutex);
594 	BUG_ON(ret);
595 
596 	cpu_usage_0 = get_cpu_usage_nsec_parent();
597 
598 	pthread_mutex_unlock(&sched->start_work_mutex);
599 
600 	for (i = 0; i < sched->nr_tasks; i++) {
601 		task = sched->tasks[i];
602 		ret = sem_wait(&task->work_done_sem);
603 		BUG_ON(ret);
604 		sem_init(&task->work_done_sem, 0, 0);
605 		sched->cpu_usage += task->cpu_usage;
606 		task->cpu_usage = 0;
607 	}
608 
609 	cpu_usage_1 = get_cpu_usage_nsec_parent();
610 	if (!sched->runavg_cpu_usage)
611 		sched->runavg_cpu_usage = sched->cpu_usage;
612 	sched->runavg_cpu_usage = (sched->runavg_cpu_usage * (sched->replay_repeat - 1) + sched->cpu_usage) / sched->replay_repeat;
613 
614 	sched->parent_cpu_usage = cpu_usage_1 - cpu_usage_0;
615 	if (!sched->runavg_parent_cpu_usage)
616 		sched->runavg_parent_cpu_usage = sched->parent_cpu_usage;
617 	sched->runavg_parent_cpu_usage = (sched->runavg_parent_cpu_usage * (sched->replay_repeat - 1) +
618 					 sched->parent_cpu_usage)/sched->replay_repeat;
619 
620 	ret = pthread_mutex_lock(&sched->start_work_mutex);
621 	BUG_ON(ret);
622 
623 	for (i = 0; i < sched->nr_tasks; i++) {
624 		task = sched->tasks[i];
625 		sem_init(&task->sleep_sem, 0, 0);
626 		task->curr_event = 0;
627 	}
628 }
629 
630 static void run_one_test(struct perf_sched *sched)
631 {
632 	u64 T0, T1, delta, avg_delta, fluct;
633 
634 	T0 = get_nsecs();
635 	wait_for_tasks(sched);
636 	T1 = get_nsecs();
637 
638 	delta = T1 - T0;
639 	sched->sum_runtime += delta;
640 	sched->nr_runs++;
641 
642 	avg_delta = sched->sum_runtime / sched->nr_runs;
643 	if (delta < avg_delta)
644 		fluct = avg_delta - delta;
645 	else
646 		fluct = delta - avg_delta;
647 	sched->sum_fluct += fluct;
648 	if (!sched->run_avg)
649 		sched->run_avg = delta;
650 	sched->run_avg = (sched->run_avg * (sched->replay_repeat - 1) + delta) / sched->replay_repeat;
651 
652 	printf("#%-3ld: %0.3f, ", sched->nr_runs, (double)delta / 1000000.0);
653 
654 	printf("ravg: %0.2f, ", (double)sched->run_avg / 1e6);
655 
656 	printf("cpu: %0.2f / %0.2f",
657 		(double)sched->cpu_usage / 1e6, (double)sched->runavg_cpu_usage / 1e6);
658 
659 #if 0
660 	/*
661 	 * rusage statistics done by the parent, these are less
662 	 * accurate than the sched->sum_exec_runtime based statistics:
663 	 */
664 	printf(" [%0.2f / %0.2f]",
665 		(double)sched->parent_cpu_usage/1e6,
666 		(double)sched->runavg_parent_cpu_usage/1e6);
667 #endif
668 
669 	printf("\n");
670 
671 	if (sched->nr_sleep_corrections)
672 		printf(" (%ld sleep corrections)\n", sched->nr_sleep_corrections);
673 	sched->nr_sleep_corrections = 0;
674 }
675 
676 static void test_calibrations(struct perf_sched *sched)
677 {
678 	u64 T0, T1;
679 
680 	T0 = get_nsecs();
681 	burn_nsecs(sched, 1e6);
682 	T1 = get_nsecs();
683 
684 	printf("the run test took %" PRIu64 " nsecs\n", T1 - T0);
685 
686 	T0 = get_nsecs();
687 	sleep_nsecs(1e6);
688 	T1 = get_nsecs();
689 
690 	printf("the sleep test took %" PRIu64 " nsecs\n", T1 - T0);
691 }
692 
693 static int
694 replay_wakeup_event(struct perf_sched *sched,
695 		    struct perf_evsel *evsel, struct perf_sample *sample,
696 		    struct machine *machine __maybe_unused)
697 {
698 	const char *comm = perf_evsel__strval(evsel, sample, "comm");
699 	const u32 pid	 = perf_evsel__intval(evsel, sample, "pid");
700 	struct task_desc *waker, *wakee;
701 
702 	if (verbose) {
703 		printf("sched_wakeup event %p\n", evsel);
704 
705 		printf(" ... pid %d woke up %s/%d\n", sample->tid, comm, pid);
706 	}
707 
708 	waker = register_pid(sched, sample->tid, "<unknown>");
709 	wakee = register_pid(sched, pid, comm);
710 
711 	add_sched_event_wakeup(sched, waker, sample->time, wakee);
712 	return 0;
713 }
714 
715 static int replay_switch_event(struct perf_sched *sched,
716 			       struct perf_evsel *evsel,
717 			       struct perf_sample *sample,
718 			       struct machine *machine __maybe_unused)
719 {
720 	const char *prev_comm  = perf_evsel__strval(evsel, sample, "prev_comm"),
721 		   *next_comm  = perf_evsel__strval(evsel, sample, "next_comm");
722 	const u32 prev_pid = perf_evsel__intval(evsel, sample, "prev_pid"),
723 		  next_pid = perf_evsel__intval(evsel, sample, "next_pid");
724 	const u64 prev_state = perf_evsel__intval(evsel, sample, "prev_state");
725 	struct task_desc *prev, __maybe_unused *next;
726 	u64 timestamp0, timestamp = sample->time;
727 	int cpu = sample->cpu;
728 	s64 delta;
729 
730 	if (verbose)
731 		printf("sched_switch event %p\n", evsel);
732 
733 	if (cpu >= MAX_CPUS || cpu < 0)
734 		return 0;
735 
736 	timestamp0 = sched->cpu_last_switched[cpu];
737 	if (timestamp0)
738 		delta = timestamp - timestamp0;
739 	else
740 		delta = 0;
741 
742 	if (delta < 0) {
743 		pr_err("hm, delta: %" PRIu64 " < 0 ?\n", delta);
744 		return -1;
745 	}
746 
747 	pr_debug(" ... switch from %s/%d to %s/%d [ran %" PRIu64 " nsecs]\n",
748 		 prev_comm, prev_pid, next_comm, next_pid, delta);
749 
750 	prev = register_pid(sched, prev_pid, prev_comm);
751 	next = register_pid(sched, next_pid, next_comm);
752 
753 	sched->cpu_last_switched[cpu] = timestamp;
754 
755 	add_sched_event_run(sched, prev, timestamp, delta);
756 	add_sched_event_sleep(sched, prev, timestamp, prev_state);
757 
758 	return 0;
759 }
760 
761 static int replay_fork_event(struct perf_sched *sched,
762 			     union perf_event *event,
763 			     struct machine *machine)
764 {
765 	struct thread *child, *parent;
766 
767 	child = machine__findnew_thread(machine, event->fork.pid,
768 					event->fork.tid);
769 	parent = machine__findnew_thread(machine, event->fork.ppid,
770 					 event->fork.ptid);
771 
772 	if (child == NULL || parent == NULL) {
773 		pr_debug("thread does not exist on fork event: child %p, parent %p\n",
774 				 child, parent);
775 		goto out_put;
776 	}
777 
778 	if (verbose) {
779 		printf("fork event\n");
780 		printf("... parent: %s/%d\n", thread__comm_str(parent), parent->tid);
781 		printf("...  child: %s/%d\n", thread__comm_str(child), child->tid);
782 	}
783 
784 	register_pid(sched, parent->tid, thread__comm_str(parent));
785 	register_pid(sched, child->tid, thread__comm_str(child));
786 out_put:
787 	thread__put(child);
788 	thread__put(parent);
789 	return 0;
790 }
791 
792 struct sort_dimension {
793 	const char		*name;
794 	sort_fn_t		cmp;
795 	struct list_head	list;
796 };
797 
798 static int
799 thread_lat_cmp(struct list_head *list, struct work_atoms *l, struct work_atoms *r)
800 {
801 	struct sort_dimension *sort;
802 	int ret = 0;
803 
804 	BUG_ON(list_empty(list));
805 
806 	list_for_each_entry(sort, list, list) {
807 		ret = sort->cmp(l, r);
808 		if (ret)
809 			return ret;
810 	}
811 
812 	return ret;
813 }
814 
815 static struct work_atoms *
816 thread_atoms_search(struct rb_root *root, struct thread *thread,
817 			 struct list_head *sort_list)
818 {
819 	struct rb_node *node = root->rb_node;
820 	struct work_atoms key = { .thread = thread };
821 
822 	while (node) {
823 		struct work_atoms *atoms;
824 		int cmp;
825 
826 		atoms = container_of(node, struct work_atoms, node);
827 
828 		cmp = thread_lat_cmp(sort_list, &key, atoms);
829 		if (cmp > 0)
830 			node = node->rb_left;
831 		else if (cmp < 0)
832 			node = node->rb_right;
833 		else {
834 			BUG_ON(thread != atoms->thread);
835 			return atoms;
836 		}
837 	}
838 	return NULL;
839 }
840 
841 static void
842 __thread_latency_insert(struct rb_root *root, struct work_atoms *data,
843 			 struct list_head *sort_list)
844 {
845 	struct rb_node **new = &(root->rb_node), *parent = NULL;
846 
847 	while (*new) {
848 		struct work_atoms *this;
849 		int cmp;
850 
851 		this = container_of(*new, struct work_atoms, node);
852 		parent = *new;
853 
854 		cmp = thread_lat_cmp(sort_list, data, this);
855 
856 		if (cmp > 0)
857 			new = &((*new)->rb_left);
858 		else
859 			new = &((*new)->rb_right);
860 	}
861 
862 	rb_link_node(&data->node, parent, new);
863 	rb_insert_color(&data->node, root);
864 }
865 
866 static int thread_atoms_insert(struct perf_sched *sched, struct thread *thread)
867 {
868 	struct work_atoms *atoms = zalloc(sizeof(*atoms));
869 	if (!atoms) {
870 		pr_err("No memory at %s\n", __func__);
871 		return -1;
872 	}
873 
874 	atoms->thread = thread__get(thread);
875 	INIT_LIST_HEAD(&atoms->work_list);
876 	__thread_latency_insert(&sched->atom_root, atoms, &sched->cmp_pid);
877 	return 0;
878 }
879 
880 static char sched_out_state(u64 prev_state)
881 {
882 	const char *str = TASK_STATE_TO_CHAR_STR;
883 
884 	return str[prev_state];
885 }
886 
887 static int
888 add_sched_out_event(struct work_atoms *atoms,
889 		    char run_state,
890 		    u64 timestamp)
891 {
892 	struct work_atom *atom = zalloc(sizeof(*atom));
893 	if (!atom) {
894 		pr_err("Non memory at %s", __func__);
895 		return -1;
896 	}
897 
898 	atom->sched_out_time = timestamp;
899 
900 	if (run_state == 'R') {
901 		atom->state = THREAD_WAIT_CPU;
902 		atom->wake_up_time = atom->sched_out_time;
903 	}
904 
905 	list_add_tail(&atom->list, &atoms->work_list);
906 	return 0;
907 }
908 
909 static void
910 add_runtime_event(struct work_atoms *atoms, u64 delta,
911 		  u64 timestamp __maybe_unused)
912 {
913 	struct work_atom *atom;
914 
915 	BUG_ON(list_empty(&atoms->work_list));
916 
917 	atom = list_entry(atoms->work_list.prev, struct work_atom, list);
918 
919 	atom->runtime += delta;
920 	atoms->total_runtime += delta;
921 }
922 
923 static void
924 add_sched_in_event(struct work_atoms *atoms, u64 timestamp)
925 {
926 	struct work_atom *atom;
927 	u64 delta;
928 
929 	if (list_empty(&atoms->work_list))
930 		return;
931 
932 	atom = list_entry(atoms->work_list.prev, struct work_atom, list);
933 
934 	if (atom->state != THREAD_WAIT_CPU)
935 		return;
936 
937 	if (timestamp < atom->wake_up_time) {
938 		atom->state = THREAD_IGNORE;
939 		return;
940 	}
941 
942 	atom->state = THREAD_SCHED_IN;
943 	atom->sched_in_time = timestamp;
944 
945 	delta = atom->sched_in_time - atom->wake_up_time;
946 	atoms->total_lat += delta;
947 	if (delta > atoms->max_lat) {
948 		atoms->max_lat = delta;
949 		atoms->max_lat_at = timestamp;
950 	}
951 	atoms->nb_atoms++;
952 }
953 
954 static int latency_switch_event(struct perf_sched *sched,
955 				struct perf_evsel *evsel,
956 				struct perf_sample *sample,
957 				struct machine *machine)
958 {
959 	const u32 prev_pid = perf_evsel__intval(evsel, sample, "prev_pid"),
960 		  next_pid = perf_evsel__intval(evsel, sample, "next_pid");
961 	const u64 prev_state = perf_evsel__intval(evsel, sample, "prev_state");
962 	struct work_atoms *out_events, *in_events;
963 	struct thread *sched_out, *sched_in;
964 	u64 timestamp0, timestamp = sample->time;
965 	int cpu = sample->cpu, err = -1;
966 	s64 delta;
967 
968 	BUG_ON(cpu >= MAX_CPUS || cpu < 0);
969 
970 	timestamp0 = sched->cpu_last_switched[cpu];
971 	sched->cpu_last_switched[cpu] = timestamp;
972 	if (timestamp0)
973 		delta = timestamp - timestamp0;
974 	else
975 		delta = 0;
976 
977 	if (delta < 0) {
978 		pr_err("hm, delta: %" PRIu64 " < 0 ?\n", delta);
979 		return -1;
980 	}
981 
982 	sched_out = machine__findnew_thread(machine, -1, prev_pid);
983 	sched_in = machine__findnew_thread(machine, -1, next_pid);
984 	if (sched_out == NULL || sched_in == NULL)
985 		goto out_put;
986 
987 	out_events = thread_atoms_search(&sched->atom_root, sched_out, &sched->cmp_pid);
988 	if (!out_events) {
989 		if (thread_atoms_insert(sched, sched_out))
990 			goto out_put;
991 		out_events = thread_atoms_search(&sched->atom_root, sched_out, &sched->cmp_pid);
992 		if (!out_events) {
993 			pr_err("out-event: Internal tree error");
994 			goto out_put;
995 		}
996 	}
997 	if (add_sched_out_event(out_events, sched_out_state(prev_state), timestamp))
998 		return -1;
999 
1000 	in_events = thread_atoms_search(&sched->atom_root, sched_in, &sched->cmp_pid);
1001 	if (!in_events) {
1002 		if (thread_atoms_insert(sched, sched_in))
1003 			goto out_put;
1004 		in_events = thread_atoms_search(&sched->atom_root, sched_in, &sched->cmp_pid);
1005 		if (!in_events) {
1006 			pr_err("in-event: Internal tree error");
1007 			goto out_put;
1008 		}
1009 		/*
1010 		 * Take came in we have not heard about yet,
1011 		 * add in an initial atom in runnable state:
1012 		 */
1013 		if (add_sched_out_event(in_events, 'R', timestamp))
1014 			goto out_put;
1015 	}
1016 	add_sched_in_event(in_events, timestamp);
1017 	err = 0;
1018 out_put:
1019 	thread__put(sched_out);
1020 	thread__put(sched_in);
1021 	return err;
1022 }
1023 
1024 static int latency_runtime_event(struct perf_sched *sched,
1025 				 struct perf_evsel *evsel,
1026 				 struct perf_sample *sample,
1027 				 struct machine *machine)
1028 {
1029 	const u32 pid	   = perf_evsel__intval(evsel, sample, "pid");
1030 	const u64 runtime  = perf_evsel__intval(evsel, sample, "runtime");
1031 	struct thread *thread = machine__findnew_thread(machine, -1, pid);
1032 	struct work_atoms *atoms = thread_atoms_search(&sched->atom_root, thread, &sched->cmp_pid);
1033 	u64 timestamp = sample->time;
1034 	int cpu = sample->cpu, err = -1;
1035 
1036 	if (thread == NULL)
1037 		return -1;
1038 
1039 	BUG_ON(cpu >= MAX_CPUS || cpu < 0);
1040 	if (!atoms) {
1041 		if (thread_atoms_insert(sched, thread))
1042 			goto out_put;
1043 		atoms = thread_atoms_search(&sched->atom_root, thread, &sched->cmp_pid);
1044 		if (!atoms) {
1045 			pr_err("in-event: Internal tree error");
1046 			goto out_put;
1047 		}
1048 		if (add_sched_out_event(atoms, 'R', timestamp))
1049 			goto out_put;
1050 	}
1051 
1052 	add_runtime_event(atoms, runtime, timestamp);
1053 	err = 0;
1054 out_put:
1055 	thread__put(thread);
1056 	return err;
1057 }
1058 
1059 static int latency_wakeup_event(struct perf_sched *sched,
1060 				struct perf_evsel *evsel,
1061 				struct perf_sample *sample,
1062 				struct machine *machine)
1063 {
1064 	const u32 pid	  = perf_evsel__intval(evsel, sample, "pid");
1065 	struct work_atoms *atoms;
1066 	struct work_atom *atom;
1067 	struct thread *wakee;
1068 	u64 timestamp = sample->time;
1069 	int err = -1;
1070 
1071 	wakee = machine__findnew_thread(machine, -1, pid);
1072 	if (wakee == NULL)
1073 		return -1;
1074 	atoms = thread_atoms_search(&sched->atom_root, wakee, &sched->cmp_pid);
1075 	if (!atoms) {
1076 		if (thread_atoms_insert(sched, wakee))
1077 			goto out_put;
1078 		atoms = thread_atoms_search(&sched->atom_root, wakee, &sched->cmp_pid);
1079 		if (!atoms) {
1080 			pr_err("wakeup-event: Internal tree error");
1081 			goto out_put;
1082 		}
1083 		if (add_sched_out_event(atoms, 'S', timestamp))
1084 			goto out_put;
1085 	}
1086 
1087 	BUG_ON(list_empty(&atoms->work_list));
1088 
1089 	atom = list_entry(atoms->work_list.prev, struct work_atom, list);
1090 
1091 	/*
1092 	 * As we do not guarantee the wakeup event happens when
1093 	 * task is out of run queue, also may happen when task is
1094 	 * on run queue and wakeup only change ->state to TASK_RUNNING,
1095 	 * then we should not set the ->wake_up_time when wake up a
1096 	 * task which is on run queue.
1097 	 *
1098 	 * You WILL be missing events if you've recorded only
1099 	 * one CPU, or are only looking at only one, so don't
1100 	 * skip in this case.
1101 	 */
1102 	if (sched->profile_cpu == -1 && atom->state != THREAD_SLEEPING)
1103 		goto out_ok;
1104 
1105 	sched->nr_timestamps++;
1106 	if (atom->sched_out_time > timestamp) {
1107 		sched->nr_unordered_timestamps++;
1108 		goto out_ok;
1109 	}
1110 
1111 	atom->state = THREAD_WAIT_CPU;
1112 	atom->wake_up_time = timestamp;
1113 out_ok:
1114 	err = 0;
1115 out_put:
1116 	thread__put(wakee);
1117 	return err;
1118 }
1119 
1120 static int latency_migrate_task_event(struct perf_sched *sched,
1121 				      struct perf_evsel *evsel,
1122 				      struct perf_sample *sample,
1123 				      struct machine *machine)
1124 {
1125 	const u32 pid = perf_evsel__intval(evsel, sample, "pid");
1126 	u64 timestamp = sample->time;
1127 	struct work_atoms *atoms;
1128 	struct work_atom *atom;
1129 	struct thread *migrant;
1130 	int err = -1;
1131 
1132 	/*
1133 	 * Only need to worry about migration when profiling one CPU.
1134 	 */
1135 	if (sched->profile_cpu == -1)
1136 		return 0;
1137 
1138 	migrant = machine__findnew_thread(machine, -1, pid);
1139 	if (migrant == NULL)
1140 		return -1;
1141 	atoms = thread_atoms_search(&sched->atom_root, migrant, &sched->cmp_pid);
1142 	if (!atoms) {
1143 		if (thread_atoms_insert(sched, migrant))
1144 			goto out_put;
1145 		register_pid(sched, migrant->tid, thread__comm_str(migrant));
1146 		atoms = thread_atoms_search(&sched->atom_root, migrant, &sched->cmp_pid);
1147 		if (!atoms) {
1148 			pr_err("migration-event: Internal tree error");
1149 			goto out_put;
1150 		}
1151 		if (add_sched_out_event(atoms, 'R', timestamp))
1152 			goto out_put;
1153 	}
1154 
1155 	BUG_ON(list_empty(&atoms->work_list));
1156 
1157 	atom = list_entry(atoms->work_list.prev, struct work_atom, list);
1158 	atom->sched_in_time = atom->sched_out_time = atom->wake_up_time = timestamp;
1159 
1160 	sched->nr_timestamps++;
1161 
1162 	if (atom->sched_out_time > timestamp)
1163 		sched->nr_unordered_timestamps++;
1164 	err = 0;
1165 out_put:
1166 	thread__put(migrant);
1167 	return err;
1168 }
1169 
1170 static void output_lat_thread(struct perf_sched *sched, struct work_atoms *work_list)
1171 {
1172 	int i;
1173 	int ret;
1174 	u64 avg;
1175 
1176 	if (!work_list->nb_atoms)
1177 		return;
1178 	/*
1179 	 * Ignore idle threads:
1180 	 */
1181 	if (!strcmp(thread__comm_str(work_list->thread), "swapper"))
1182 		return;
1183 
1184 	sched->all_runtime += work_list->total_runtime;
1185 	sched->all_count   += work_list->nb_atoms;
1186 
1187 	if (work_list->num_merged > 1)
1188 		ret = printf("  %s:(%d) ", thread__comm_str(work_list->thread), work_list->num_merged);
1189 	else
1190 		ret = printf("  %s:%d ", thread__comm_str(work_list->thread), work_list->thread->tid);
1191 
1192 	for (i = 0; i < 24 - ret; i++)
1193 		printf(" ");
1194 
1195 	avg = work_list->total_lat / work_list->nb_atoms;
1196 
1197 	printf("|%11.3f ms |%9" PRIu64 " | avg:%9.3f ms | max:%9.3f ms | max at: %13.6f s\n",
1198 	      (double)work_list->total_runtime / 1e6,
1199 		 work_list->nb_atoms, (double)avg / 1e6,
1200 		 (double)work_list->max_lat / 1e6,
1201 		 (double)work_list->max_lat_at / 1e9);
1202 }
1203 
1204 static int pid_cmp(struct work_atoms *l, struct work_atoms *r)
1205 {
1206 	if (l->thread->tid < r->thread->tid)
1207 		return -1;
1208 	if (l->thread->tid > r->thread->tid)
1209 		return 1;
1210 
1211 	return 0;
1212 }
1213 
1214 static int avg_cmp(struct work_atoms *l, struct work_atoms *r)
1215 {
1216 	u64 avgl, avgr;
1217 
1218 	if (!l->nb_atoms)
1219 		return -1;
1220 
1221 	if (!r->nb_atoms)
1222 		return 1;
1223 
1224 	avgl = l->total_lat / l->nb_atoms;
1225 	avgr = r->total_lat / r->nb_atoms;
1226 
1227 	if (avgl < avgr)
1228 		return -1;
1229 	if (avgl > avgr)
1230 		return 1;
1231 
1232 	return 0;
1233 }
1234 
1235 static int max_cmp(struct work_atoms *l, struct work_atoms *r)
1236 {
1237 	if (l->max_lat < r->max_lat)
1238 		return -1;
1239 	if (l->max_lat > r->max_lat)
1240 		return 1;
1241 
1242 	return 0;
1243 }
1244 
1245 static int switch_cmp(struct work_atoms *l, struct work_atoms *r)
1246 {
1247 	if (l->nb_atoms < r->nb_atoms)
1248 		return -1;
1249 	if (l->nb_atoms > r->nb_atoms)
1250 		return 1;
1251 
1252 	return 0;
1253 }
1254 
1255 static int runtime_cmp(struct work_atoms *l, struct work_atoms *r)
1256 {
1257 	if (l->total_runtime < r->total_runtime)
1258 		return -1;
1259 	if (l->total_runtime > r->total_runtime)
1260 		return 1;
1261 
1262 	return 0;
1263 }
1264 
1265 static int sort_dimension__add(const char *tok, struct list_head *list)
1266 {
1267 	size_t i;
1268 	static struct sort_dimension avg_sort_dimension = {
1269 		.name = "avg",
1270 		.cmp  = avg_cmp,
1271 	};
1272 	static struct sort_dimension max_sort_dimension = {
1273 		.name = "max",
1274 		.cmp  = max_cmp,
1275 	};
1276 	static struct sort_dimension pid_sort_dimension = {
1277 		.name = "pid",
1278 		.cmp  = pid_cmp,
1279 	};
1280 	static struct sort_dimension runtime_sort_dimension = {
1281 		.name = "runtime",
1282 		.cmp  = runtime_cmp,
1283 	};
1284 	static struct sort_dimension switch_sort_dimension = {
1285 		.name = "switch",
1286 		.cmp  = switch_cmp,
1287 	};
1288 	struct sort_dimension *available_sorts[] = {
1289 		&pid_sort_dimension,
1290 		&avg_sort_dimension,
1291 		&max_sort_dimension,
1292 		&switch_sort_dimension,
1293 		&runtime_sort_dimension,
1294 	};
1295 
1296 	for (i = 0; i < ARRAY_SIZE(available_sorts); i++) {
1297 		if (!strcmp(available_sorts[i]->name, tok)) {
1298 			list_add_tail(&available_sorts[i]->list, list);
1299 
1300 			return 0;
1301 		}
1302 	}
1303 
1304 	return -1;
1305 }
1306 
1307 static void perf_sched__sort_lat(struct perf_sched *sched)
1308 {
1309 	struct rb_node *node;
1310 	struct rb_root *root = &sched->atom_root;
1311 again:
1312 	for (;;) {
1313 		struct work_atoms *data;
1314 		node = rb_first(root);
1315 		if (!node)
1316 			break;
1317 
1318 		rb_erase(node, root);
1319 		data = rb_entry(node, struct work_atoms, node);
1320 		__thread_latency_insert(&sched->sorted_atom_root, data, &sched->sort_list);
1321 	}
1322 	if (root == &sched->atom_root) {
1323 		root = &sched->merged_atom_root;
1324 		goto again;
1325 	}
1326 }
1327 
1328 static int process_sched_wakeup_event(struct perf_tool *tool,
1329 				      struct perf_evsel *evsel,
1330 				      struct perf_sample *sample,
1331 				      struct machine *machine)
1332 {
1333 	struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
1334 
1335 	if (sched->tp_handler->wakeup_event)
1336 		return sched->tp_handler->wakeup_event(sched, evsel, sample, machine);
1337 
1338 	return 0;
1339 }
1340 
1341 static int map_switch_event(struct perf_sched *sched, struct perf_evsel *evsel,
1342 			    struct perf_sample *sample, struct machine *machine)
1343 {
1344 	const u32 next_pid = perf_evsel__intval(evsel, sample, "next_pid");
1345 	struct thread *sched_in;
1346 	int new_shortname;
1347 	u64 timestamp0, timestamp = sample->time;
1348 	s64 delta;
1349 	int cpu, this_cpu = sample->cpu;
1350 
1351 	BUG_ON(this_cpu >= MAX_CPUS || this_cpu < 0);
1352 
1353 	if (this_cpu > sched->max_cpu)
1354 		sched->max_cpu = this_cpu;
1355 
1356 	timestamp0 = sched->cpu_last_switched[this_cpu];
1357 	sched->cpu_last_switched[this_cpu] = timestamp;
1358 	if (timestamp0)
1359 		delta = timestamp - timestamp0;
1360 	else
1361 		delta = 0;
1362 
1363 	if (delta < 0) {
1364 		pr_err("hm, delta: %" PRIu64 " < 0 ?\n", delta);
1365 		return -1;
1366 	}
1367 
1368 	sched_in = machine__findnew_thread(machine, -1, next_pid);
1369 	if (sched_in == NULL)
1370 		return -1;
1371 
1372 	sched->curr_thread[this_cpu] = thread__get(sched_in);
1373 
1374 	printf("  ");
1375 
1376 	new_shortname = 0;
1377 	if (!sched_in->shortname[0]) {
1378 		if (!strcmp(thread__comm_str(sched_in), "swapper")) {
1379 			/*
1380 			 * Don't allocate a letter-number for swapper:0
1381 			 * as a shortname. Instead, we use '.' for it.
1382 			 */
1383 			sched_in->shortname[0] = '.';
1384 			sched_in->shortname[1] = ' ';
1385 		} else {
1386 			sched_in->shortname[0] = sched->next_shortname1;
1387 			sched_in->shortname[1] = sched->next_shortname2;
1388 
1389 			if (sched->next_shortname1 < 'Z') {
1390 				sched->next_shortname1++;
1391 			} else {
1392 				sched->next_shortname1 = 'A';
1393 				if (sched->next_shortname2 < '9')
1394 					sched->next_shortname2++;
1395 				else
1396 					sched->next_shortname2 = '0';
1397 			}
1398 		}
1399 		new_shortname = 1;
1400 	}
1401 
1402 	for (cpu = 0; cpu <= sched->max_cpu; cpu++) {
1403 		if (cpu != this_cpu)
1404 			printf(" ");
1405 		else
1406 			printf("*");
1407 
1408 		if (sched->curr_thread[cpu])
1409 			printf("%2s ", sched->curr_thread[cpu]->shortname);
1410 		else
1411 			printf("   ");
1412 	}
1413 
1414 	printf("  %12.6f secs ", (double)timestamp/1e9);
1415 	if (new_shortname) {
1416 		printf("%s => %s:%d\n",
1417 		       sched_in->shortname, thread__comm_str(sched_in), sched_in->tid);
1418 	} else {
1419 		printf("\n");
1420 	}
1421 
1422 	thread__put(sched_in);
1423 
1424 	return 0;
1425 }
1426 
1427 static int process_sched_switch_event(struct perf_tool *tool,
1428 				      struct perf_evsel *evsel,
1429 				      struct perf_sample *sample,
1430 				      struct machine *machine)
1431 {
1432 	struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
1433 	int this_cpu = sample->cpu, err = 0;
1434 	u32 prev_pid = perf_evsel__intval(evsel, sample, "prev_pid"),
1435 	    next_pid = perf_evsel__intval(evsel, sample, "next_pid");
1436 
1437 	if (sched->curr_pid[this_cpu] != (u32)-1) {
1438 		/*
1439 		 * Are we trying to switch away a PID that is
1440 		 * not current?
1441 		 */
1442 		if (sched->curr_pid[this_cpu] != prev_pid)
1443 			sched->nr_context_switch_bugs++;
1444 	}
1445 
1446 	if (sched->tp_handler->switch_event)
1447 		err = sched->tp_handler->switch_event(sched, evsel, sample, machine);
1448 
1449 	sched->curr_pid[this_cpu] = next_pid;
1450 	return err;
1451 }
1452 
1453 static int process_sched_runtime_event(struct perf_tool *tool,
1454 				       struct perf_evsel *evsel,
1455 				       struct perf_sample *sample,
1456 				       struct machine *machine)
1457 {
1458 	struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
1459 
1460 	if (sched->tp_handler->runtime_event)
1461 		return sched->tp_handler->runtime_event(sched, evsel, sample, machine);
1462 
1463 	return 0;
1464 }
1465 
1466 static int perf_sched__process_fork_event(struct perf_tool *tool,
1467 					  union perf_event *event,
1468 					  struct perf_sample *sample,
1469 					  struct machine *machine)
1470 {
1471 	struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
1472 
1473 	/* run the fork event through the perf machineruy */
1474 	perf_event__process_fork(tool, event, sample, machine);
1475 
1476 	/* and then run additional processing needed for this command */
1477 	if (sched->tp_handler->fork_event)
1478 		return sched->tp_handler->fork_event(sched, event, machine);
1479 
1480 	return 0;
1481 }
1482 
1483 static int process_sched_migrate_task_event(struct perf_tool *tool,
1484 					    struct perf_evsel *evsel,
1485 					    struct perf_sample *sample,
1486 					    struct machine *machine)
1487 {
1488 	struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
1489 
1490 	if (sched->tp_handler->migrate_task_event)
1491 		return sched->tp_handler->migrate_task_event(sched, evsel, sample, machine);
1492 
1493 	return 0;
1494 }
1495 
1496 typedef int (*tracepoint_handler)(struct perf_tool *tool,
1497 				  struct perf_evsel *evsel,
1498 				  struct perf_sample *sample,
1499 				  struct machine *machine);
1500 
1501 static int perf_sched__process_tracepoint_sample(struct perf_tool *tool __maybe_unused,
1502 						 union perf_event *event __maybe_unused,
1503 						 struct perf_sample *sample,
1504 						 struct perf_evsel *evsel,
1505 						 struct machine *machine)
1506 {
1507 	int err = 0;
1508 
1509 	if (evsel->handler != NULL) {
1510 		tracepoint_handler f = evsel->handler;
1511 		err = f(tool, evsel, sample, machine);
1512 	}
1513 
1514 	return err;
1515 }
1516 
1517 static int perf_sched__read_events(struct perf_sched *sched)
1518 {
1519 	const struct perf_evsel_str_handler handlers[] = {
1520 		{ "sched:sched_switch",	      process_sched_switch_event, },
1521 		{ "sched:sched_stat_runtime", process_sched_runtime_event, },
1522 		{ "sched:sched_wakeup",	      process_sched_wakeup_event, },
1523 		{ "sched:sched_wakeup_new",   process_sched_wakeup_event, },
1524 		{ "sched:sched_migrate_task", process_sched_migrate_task_event, },
1525 	};
1526 	struct perf_session *session;
1527 	struct perf_data_file file = {
1528 		.path = input_name,
1529 		.mode = PERF_DATA_MODE_READ,
1530 		.force = sched->force,
1531 	};
1532 	int rc = -1;
1533 
1534 	session = perf_session__new(&file, false, &sched->tool);
1535 	if (session == NULL) {
1536 		pr_debug("No Memory for session\n");
1537 		return -1;
1538 	}
1539 
1540 	symbol__init(&session->header.env);
1541 
1542 	if (perf_session__set_tracepoints_handlers(session, handlers))
1543 		goto out_delete;
1544 
1545 	if (perf_session__has_traces(session, "record -R")) {
1546 		int err = perf_session__process_events(session);
1547 		if (err) {
1548 			pr_err("Failed to process events, error %d", err);
1549 			goto out_delete;
1550 		}
1551 
1552 		sched->nr_events      = session->evlist->stats.nr_events[0];
1553 		sched->nr_lost_events = session->evlist->stats.total_lost;
1554 		sched->nr_lost_chunks = session->evlist->stats.nr_events[PERF_RECORD_LOST];
1555 	}
1556 
1557 	rc = 0;
1558 out_delete:
1559 	perf_session__delete(session);
1560 	return rc;
1561 }
1562 
1563 static void print_bad_events(struct perf_sched *sched)
1564 {
1565 	if (sched->nr_unordered_timestamps && sched->nr_timestamps) {
1566 		printf("  INFO: %.3f%% unordered timestamps (%ld out of %ld)\n",
1567 			(double)sched->nr_unordered_timestamps/(double)sched->nr_timestamps*100.0,
1568 			sched->nr_unordered_timestamps, sched->nr_timestamps);
1569 	}
1570 	if (sched->nr_lost_events && sched->nr_events) {
1571 		printf("  INFO: %.3f%% lost events (%ld out of %ld, in %ld chunks)\n",
1572 			(double)sched->nr_lost_events/(double)sched->nr_events * 100.0,
1573 			sched->nr_lost_events, sched->nr_events, sched->nr_lost_chunks);
1574 	}
1575 	if (sched->nr_context_switch_bugs && sched->nr_timestamps) {
1576 		printf("  INFO: %.3f%% context switch bugs (%ld out of %ld)",
1577 			(double)sched->nr_context_switch_bugs/(double)sched->nr_timestamps*100.0,
1578 			sched->nr_context_switch_bugs, sched->nr_timestamps);
1579 		if (sched->nr_lost_events)
1580 			printf(" (due to lost events?)");
1581 		printf("\n");
1582 	}
1583 }
1584 
1585 static void __merge_work_atoms(struct rb_root *root, struct work_atoms *data)
1586 {
1587 	struct rb_node **new = &(root->rb_node), *parent = NULL;
1588 	struct work_atoms *this;
1589 	const char *comm = thread__comm_str(data->thread), *this_comm;
1590 
1591 	while (*new) {
1592 		int cmp;
1593 
1594 		this = container_of(*new, struct work_atoms, node);
1595 		parent = *new;
1596 
1597 		this_comm = thread__comm_str(this->thread);
1598 		cmp = strcmp(comm, this_comm);
1599 		if (cmp > 0) {
1600 			new = &((*new)->rb_left);
1601 		} else if (cmp < 0) {
1602 			new = &((*new)->rb_right);
1603 		} else {
1604 			this->num_merged++;
1605 			this->total_runtime += data->total_runtime;
1606 			this->nb_atoms += data->nb_atoms;
1607 			this->total_lat += data->total_lat;
1608 			list_splice(&data->work_list, &this->work_list);
1609 			if (this->max_lat < data->max_lat) {
1610 				this->max_lat = data->max_lat;
1611 				this->max_lat_at = data->max_lat_at;
1612 			}
1613 			zfree(&data);
1614 			return;
1615 		}
1616 	}
1617 
1618 	data->num_merged++;
1619 	rb_link_node(&data->node, parent, new);
1620 	rb_insert_color(&data->node, root);
1621 }
1622 
1623 static void perf_sched__merge_lat(struct perf_sched *sched)
1624 {
1625 	struct work_atoms *data;
1626 	struct rb_node *node;
1627 
1628 	if (sched->skip_merge)
1629 		return;
1630 
1631 	while ((node = rb_first(&sched->atom_root))) {
1632 		rb_erase(node, &sched->atom_root);
1633 		data = rb_entry(node, struct work_atoms, node);
1634 		__merge_work_atoms(&sched->merged_atom_root, data);
1635 	}
1636 }
1637 
1638 static int perf_sched__lat(struct perf_sched *sched)
1639 {
1640 	struct rb_node *next;
1641 
1642 	setup_pager();
1643 
1644 	if (perf_sched__read_events(sched))
1645 		return -1;
1646 
1647 	perf_sched__merge_lat(sched);
1648 	perf_sched__sort_lat(sched);
1649 
1650 	printf("\n -----------------------------------------------------------------------------------------------------------------\n");
1651 	printf("  Task                  |   Runtime ms  | Switches | Average delay ms | Maximum delay ms | Maximum delay at       |\n");
1652 	printf(" -----------------------------------------------------------------------------------------------------------------\n");
1653 
1654 	next = rb_first(&sched->sorted_atom_root);
1655 
1656 	while (next) {
1657 		struct work_atoms *work_list;
1658 
1659 		work_list = rb_entry(next, struct work_atoms, node);
1660 		output_lat_thread(sched, work_list);
1661 		next = rb_next(next);
1662 		thread__zput(work_list->thread);
1663 	}
1664 
1665 	printf(" -----------------------------------------------------------------------------------------------------------------\n");
1666 	printf("  TOTAL:                |%11.3f ms |%9" PRIu64 " |\n",
1667 		(double)sched->all_runtime / 1e6, sched->all_count);
1668 
1669 	printf(" ---------------------------------------------------\n");
1670 
1671 	print_bad_events(sched);
1672 	printf("\n");
1673 
1674 	return 0;
1675 }
1676 
1677 static int perf_sched__map(struct perf_sched *sched)
1678 {
1679 	sched->max_cpu = sysconf(_SC_NPROCESSORS_CONF);
1680 
1681 	setup_pager();
1682 	if (perf_sched__read_events(sched))
1683 		return -1;
1684 	print_bad_events(sched);
1685 	return 0;
1686 }
1687 
1688 static int perf_sched__replay(struct perf_sched *sched)
1689 {
1690 	unsigned long i;
1691 
1692 	calibrate_run_measurement_overhead(sched);
1693 	calibrate_sleep_measurement_overhead(sched);
1694 
1695 	test_calibrations(sched);
1696 
1697 	if (perf_sched__read_events(sched))
1698 		return -1;
1699 
1700 	printf("nr_run_events:        %ld\n", sched->nr_run_events);
1701 	printf("nr_sleep_events:      %ld\n", sched->nr_sleep_events);
1702 	printf("nr_wakeup_events:     %ld\n", sched->nr_wakeup_events);
1703 
1704 	if (sched->targetless_wakeups)
1705 		printf("target-less wakeups:  %ld\n", sched->targetless_wakeups);
1706 	if (sched->multitarget_wakeups)
1707 		printf("multi-target wakeups: %ld\n", sched->multitarget_wakeups);
1708 	if (sched->nr_run_events_optimized)
1709 		printf("run atoms optimized: %ld\n",
1710 			sched->nr_run_events_optimized);
1711 
1712 	print_task_traces(sched);
1713 	add_cross_task_wakeups(sched);
1714 
1715 	create_tasks(sched);
1716 	printf("------------------------------------------------------------\n");
1717 	for (i = 0; i < sched->replay_repeat; i++)
1718 		run_one_test(sched);
1719 
1720 	return 0;
1721 }
1722 
1723 static void setup_sorting(struct perf_sched *sched, const struct option *options,
1724 			  const char * const usage_msg[])
1725 {
1726 	char *tmp, *tok, *str = strdup(sched->sort_order);
1727 
1728 	for (tok = strtok_r(str, ", ", &tmp);
1729 			tok; tok = strtok_r(NULL, ", ", &tmp)) {
1730 		if (sort_dimension__add(tok, &sched->sort_list) < 0) {
1731 			error("Unknown --sort key: `%s'", tok);
1732 			usage_with_options(usage_msg, options);
1733 		}
1734 	}
1735 
1736 	free(str);
1737 
1738 	sort_dimension__add("pid", &sched->cmp_pid);
1739 }
1740 
1741 static int __cmd_record(int argc, const char **argv)
1742 {
1743 	unsigned int rec_argc, i, j;
1744 	const char **rec_argv;
1745 	const char * const record_args[] = {
1746 		"record",
1747 		"-a",
1748 		"-R",
1749 		"-m", "1024",
1750 		"-c", "1",
1751 		"-e", "sched:sched_switch",
1752 		"-e", "sched:sched_stat_wait",
1753 		"-e", "sched:sched_stat_sleep",
1754 		"-e", "sched:sched_stat_iowait",
1755 		"-e", "sched:sched_stat_runtime",
1756 		"-e", "sched:sched_process_fork",
1757 		"-e", "sched:sched_wakeup",
1758 		"-e", "sched:sched_wakeup_new",
1759 		"-e", "sched:sched_migrate_task",
1760 	};
1761 
1762 	rec_argc = ARRAY_SIZE(record_args) + argc - 1;
1763 	rec_argv = calloc(rec_argc + 1, sizeof(char *));
1764 
1765 	if (rec_argv == NULL)
1766 		return -ENOMEM;
1767 
1768 	for (i = 0; i < ARRAY_SIZE(record_args); i++)
1769 		rec_argv[i] = strdup(record_args[i]);
1770 
1771 	for (j = 1; j < (unsigned int)argc; j++, i++)
1772 		rec_argv[i] = argv[j];
1773 
1774 	BUG_ON(i != rec_argc);
1775 
1776 	return cmd_record(i, rec_argv, NULL);
1777 }
1778 
1779 int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused)
1780 {
1781 	const char default_sort_order[] = "avg, max, switch, runtime";
1782 	struct perf_sched sched = {
1783 		.tool = {
1784 			.sample		 = perf_sched__process_tracepoint_sample,
1785 			.comm		 = perf_event__process_comm,
1786 			.lost		 = perf_event__process_lost,
1787 			.fork		 = perf_sched__process_fork_event,
1788 			.ordered_events = true,
1789 		},
1790 		.cmp_pid	      = LIST_HEAD_INIT(sched.cmp_pid),
1791 		.sort_list	      = LIST_HEAD_INIT(sched.sort_list),
1792 		.start_work_mutex     = PTHREAD_MUTEX_INITIALIZER,
1793 		.work_done_wait_mutex = PTHREAD_MUTEX_INITIALIZER,
1794 		.sort_order	      = default_sort_order,
1795 		.replay_repeat	      = 10,
1796 		.profile_cpu	      = -1,
1797 		.next_shortname1      = 'A',
1798 		.next_shortname2      = '0',
1799 		.skip_merge           = 0,
1800 	};
1801 	const struct option latency_options[] = {
1802 	OPT_STRING('s', "sort", &sched.sort_order, "key[,key2...]",
1803 		   "sort by key(s): runtime, switch, avg, max"),
1804 	OPT_INCR('v', "verbose", &verbose,
1805 		    "be more verbose (show symbol address, etc)"),
1806 	OPT_INTEGER('C', "CPU", &sched.profile_cpu,
1807 		    "CPU to profile on"),
1808 	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
1809 		    "dump raw trace in ASCII"),
1810 	OPT_BOOLEAN('p', "pids", &sched.skip_merge,
1811 		    "latency stats per pid instead of per comm"),
1812 	OPT_END()
1813 	};
1814 	const struct option replay_options[] = {
1815 	OPT_UINTEGER('r', "repeat", &sched.replay_repeat,
1816 		     "repeat the workload replay N times (-1: infinite)"),
1817 	OPT_INCR('v', "verbose", &verbose,
1818 		    "be more verbose (show symbol address, etc)"),
1819 	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
1820 		    "dump raw trace in ASCII"),
1821 	OPT_BOOLEAN('f', "force", &sched.force, "don't complain, do it"),
1822 	OPT_END()
1823 	};
1824 	const struct option sched_options[] = {
1825 	OPT_STRING('i', "input", &input_name, "file",
1826 		    "input file name"),
1827 	OPT_INCR('v', "verbose", &verbose,
1828 		    "be more verbose (show symbol address, etc)"),
1829 	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
1830 		    "dump raw trace in ASCII"),
1831 	OPT_END()
1832 	};
1833 	const char * const latency_usage[] = {
1834 		"perf sched latency [<options>]",
1835 		NULL
1836 	};
1837 	const char * const replay_usage[] = {
1838 		"perf sched replay [<options>]",
1839 		NULL
1840 	};
1841 	const char *const sched_subcommands[] = { "record", "latency", "map",
1842 						  "replay", "script", NULL };
1843 	const char *sched_usage[] = {
1844 		NULL,
1845 		NULL
1846 	};
1847 	struct trace_sched_handler lat_ops  = {
1848 		.wakeup_event	    = latency_wakeup_event,
1849 		.switch_event	    = latency_switch_event,
1850 		.runtime_event	    = latency_runtime_event,
1851 		.migrate_task_event = latency_migrate_task_event,
1852 	};
1853 	struct trace_sched_handler map_ops  = {
1854 		.switch_event	    = map_switch_event,
1855 	};
1856 	struct trace_sched_handler replay_ops  = {
1857 		.wakeup_event	    = replay_wakeup_event,
1858 		.switch_event	    = replay_switch_event,
1859 		.fork_event	    = replay_fork_event,
1860 	};
1861 	unsigned int i;
1862 
1863 	for (i = 0; i < ARRAY_SIZE(sched.curr_pid); i++)
1864 		sched.curr_pid[i] = -1;
1865 
1866 	argc = parse_options_subcommand(argc, argv, sched_options, sched_subcommands,
1867 					sched_usage, PARSE_OPT_STOP_AT_NON_OPTION);
1868 	if (!argc)
1869 		usage_with_options(sched_usage, sched_options);
1870 
1871 	/*
1872 	 * Aliased to 'perf script' for now:
1873 	 */
1874 	if (!strcmp(argv[0], "script"))
1875 		return cmd_script(argc, argv, prefix);
1876 
1877 	if (!strncmp(argv[0], "rec", 3)) {
1878 		return __cmd_record(argc, argv);
1879 	} else if (!strncmp(argv[0], "lat", 3)) {
1880 		sched.tp_handler = &lat_ops;
1881 		if (argc > 1) {
1882 			argc = parse_options(argc, argv, latency_options, latency_usage, 0);
1883 			if (argc)
1884 				usage_with_options(latency_usage, latency_options);
1885 		}
1886 		setup_sorting(&sched, latency_options, latency_usage);
1887 		return perf_sched__lat(&sched);
1888 	} else if (!strcmp(argv[0], "map")) {
1889 		sched.tp_handler = &map_ops;
1890 		setup_sorting(&sched, latency_options, latency_usage);
1891 		return perf_sched__map(&sched);
1892 	} else if (!strncmp(argv[0], "rep", 3)) {
1893 		sched.tp_handler = &replay_ops;
1894 		if (argc) {
1895 			argc = parse_options(argc, argv, replay_options, replay_usage, 0);
1896 			if (argc)
1897 				usage_with_options(replay_usage, replay_options);
1898 		}
1899 		return perf_sched__replay(&sched);
1900 	} else {
1901 		usage_with_options(sched_usage, sched_options);
1902 	}
1903 
1904 	return 0;
1905 }
1906