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    1aff59be
    perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task · 1aff59be
    Yunlong Song authored
    
    Since there is sem_wait for each task in the wait_for_tasks(), e.g.
    sem_wait(&task->work_done_sem).
    
    The sem_wait can continue only when work_done_sem is greater than 0, or
    it will be blocked.
    
    For perf sched replay, one task may sem_post the work_done_sem of
    another task, which causes the work_done_sem of that task processed in a
    reasonable sequence, e.g. sem_post, sem_wait, sem_wait, sem_post...
    
    This sequence simulates the sched process of the running tasks at the
    time when perf sched record runs.
    
    As a result, all the tasks are required and their threads must be
    successfully created.
    
    If any one (task A) of the tasks fails to create its thread, then
    another task (task B), whose work_done_sem needs sem_post from that
    failed task A, may likely block itself due to seg_wait.
    
    And this is a dead halt, since task B's thread_func cannot continue at
    all.
    
    To solve this problem, perf sched replay should exit once any task fails
    to create its thread.
    
    Example:
    
    Test environment: x86_64 with 160 cores
    
    Before this patch:
    
     $ perf sched replay
     ...
     Error: sys_perf_event_open() syscall returned with -1 (Too many open
     files)
     ------------------------------------------------------------    <- dead halt
    
    After this patch:
    
     $ perf sched replay
     ...
     task   1551 (           <unknown>:         0), nr_events: 10
     Error: sys_perf_event_open() syscall returned with -1 (Too many open
     files)
     $
    
    As shown above, perf sched replay finishes the process after printing an
    error message and does not block itself.
    
    Signed-off-by: default avatarYunlong Song <yunlong.song@huawei.com>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Wang Nan <wangnan0@huawei.com>
    Link: http://lkml.kernel.org/r/1427809596-29559-7-git-send-email-yunlong.song@huawei.com
    
    
    Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
    1aff59be
    History
    perf sched replay: Handle the dead halt of sem_wait when create_tasks() fails for any task
    Yunlong Song authored
    
    Since there is sem_wait for each task in the wait_for_tasks(), e.g.
    sem_wait(&task->work_done_sem).
    
    The sem_wait can continue only when work_done_sem is greater than 0, or
    it will be blocked.
    
    For perf sched replay, one task may sem_post the work_done_sem of
    another task, which causes the work_done_sem of that task processed in a
    reasonable sequence, e.g. sem_post, sem_wait, sem_wait, sem_post...
    
    This sequence simulates the sched process of the running tasks at the
    time when perf sched record runs.
    
    As a result, all the tasks are required and their threads must be
    successfully created.
    
    If any one (task A) of the tasks fails to create its thread, then
    another task (task B), whose work_done_sem needs sem_post from that
    failed task A, may likely block itself due to seg_wait.
    
    And this is a dead halt, since task B's thread_func cannot continue at
    all.
    
    To solve this problem, perf sched replay should exit once any task fails
    to create its thread.
    
    Example:
    
    Test environment: x86_64 with 160 cores
    
    Before this patch:
    
     $ perf sched replay
     ...
     Error: sys_perf_event_open() syscall returned with -1 (Too many open
     files)
     ------------------------------------------------------------    <- dead halt
    
    After this patch:
    
     $ perf sched replay
     ...
     task   1551 (           <unknown>:         0), nr_events: 10
     Error: sys_perf_event_open() syscall returned with -1 (Too many open
     files)
     $
    
    As shown above, perf sched replay finishes the process after printing an
    error message and does not block itself.
    
    Signed-off-by: default avatarYunlong Song <yunlong.song@huawei.com>
    Cc: Paul Mackerras <paulus@samba.org>
    Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
    Cc: Wang Nan <wangnan0@huawei.com>
    Link: http://lkml.kernel.org/r/1427809596-29559-7-git-send-email-yunlong.song@huawei.com
    
    
    Signed-off-by: default avatarArnaldo Carvalho de Melo <acme@redhat.com>
builtin-sched.c 44.25 KiB
#include "builtin.h"
#include "perf.h"

#include "util/util.h"
#include "util/evlist.h"
#include "util/cache.h"
#include "util/evsel.h"
#include "util/symbol.h"
#include "util/thread.h"
#include "util/header.h"
#include "util/session.h"
#include "util/tool.h"
#include "util/cloexec.h"

#include "util/parse-options.h"
#include "util/trace-event.h"

#include "util/debug.h"

#include <sys/prctl.h>
#include <sys/resource.h>

#include <semaphore.h>
#include <pthread.h>
#include <math.h>
#include <api/fs/fs.h>

#define PR_SET_NAME		15               /* Set process name */
#define MAX_CPUS		4096
#define COMM_LEN		20
#define SYM_LEN			129
#define MAX_PID			1024000

struct sched_atom;

struct task_desc {
	unsigned long		nr;
	unsigned long		pid;
	char			comm[COMM_LEN];

	unsigned long		nr_events;
	unsigned long		curr_event;
	struct sched_atom	**atoms;

	pthread_t		thread;
	sem_t			sleep_sem;

	sem_t			ready_for_work;
	sem_t			work_done_sem;

	u64			cpu_usage;
};

enum sched_event_type {
	SCHED_EVENT_RUN,
	SCHED_EVENT_SLEEP,
	SCHED_EVENT_WAKEUP,
	SCHED_EVENT_MIGRATION,
};

struct sched_atom {
	enum sched_event_type	type;
	int			specific_wait;
	u64			timestamp;
	u64			duration;
	unsigned long		nr;
	sem_t			*wait_sem;
	struct task_desc	*wakee;
};
#define TASK_STATE_TO_CHAR_STR "RSDTtZXxKWP"

enum thread_state {
	THREAD_SLEEPING = 0,
	THREAD_WAIT_CPU,
	THREAD_SCHED_IN,
	THREAD_IGNORE
};

struct work_atom {
	struct list_head	list;
	enum thread_state	state;
	u64			sched_out_time;
	u64			wake_up_time;
	u64			sched_in_time;
	u64			runtime;
};

struct work_atoms {
	struct list_head	work_list;
	struct thread		*thread;
	struct rb_node		node;
	u64			max_lat;
	u64			max_lat_at;
	u64			total_lat;
	u64			nb_atoms;
	u64			total_runtime;
};

typedef int (*sort_fn_t)(struct work_atoms *, struct work_atoms *);

struct perf_sched;

struct trace_sched_handler {
	int (*switch_event)(struct perf_sched *sched, struct perf_evsel *evsel,
			    struct perf_sample *sample, struct machine *machine);

	int (*runtime_event)(struct perf_sched *sched, struct perf_evsel *evsel,
			     struct perf_sample *sample, struct machine *machine);

	int (*wakeup_event)(struct perf_sched *sched, struct perf_evsel *evsel,
			    struct perf_sample *sample, struct machine *machine);

	/* PERF_RECORD_FORK event, not sched_process_fork tracepoint */
	int (*fork_event)(struct perf_sched *sched, union perf_event *event,
			  struct machine *machine);

	int (*migrate_task_event)(struct perf_sched *sched,
				  struct perf_evsel *evsel,
				  struct perf_sample *sample,
				  struct machine *machine);
};

struct perf_sched {
	struct perf_tool tool;
	const char	 *sort_order;
	unsigned long	 nr_tasks;
	struct task_desc **pid_to_task;
	struct task_desc **tasks;
	const struct trace_sched_handler *tp_handler;
	pthread_mutex_t	 start_work_mutex;
	pthread_mutex_t	 work_done_wait_mutex;
	int		 profile_cpu;
/*
 * Track the current task - that way we can know whether there's any
 * weird events, such as a task being switched away that is not current.
 */
	int		 max_cpu;
	u32		 curr_pid[MAX_CPUS];
	struct thread	 *curr_thread[MAX_CPUS];
	char		 next_shortname1;
	char		 next_shortname2;
	unsigned int	 replay_repeat;
	unsigned long	 nr_run_events;
	unsigned long	 nr_sleep_events;
	unsigned long	 nr_wakeup_events;
	unsigned long	 nr_sleep_corrections;
	unsigned long	 nr_run_events_optimized;
	unsigned long	 targetless_wakeups;
	unsigned long	 multitarget_wakeups;
	unsigned long	 nr_runs;
	unsigned long	 nr_timestamps;
	unsigned long	 nr_unordered_timestamps;
	unsigned long	 nr_context_switch_bugs;
	unsigned long	 nr_events;
	unsigned long	 nr_lost_chunks;
	unsigned long	 nr_lost_events;
	u64		 run_measurement_overhead;
	u64		 sleep_measurement_overhead;
	u64		 start_time;
	u64		 cpu_usage;
	u64		 runavg_cpu_usage;
	u64		 parent_cpu_usage;
	u64		 runavg_parent_cpu_usage;
	u64		 sum_runtime;
	u64		 sum_fluct;
	u64		 run_avg;
	u64		 all_runtime;
	u64		 all_count;
	u64		 cpu_last_switched[MAX_CPUS];
	struct rb_root	 atom_root, sorted_atom_root;
	struct list_head sort_list, cmp_pid;
};

static u64 get_nsecs(void)
{
	struct timespec ts;

	clock_gettime(CLOCK_MONOTONIC, &ts);

	return ts.tv_sec * 1000000000ULL + ts.tv_nsec;
}

static void burn_nsecs(struct perf_sched *sched, u64 nsecs)
{
	u64 T0 = get_nsecs(), T1;

	do {
		T1 = get_nsecs();
	} while (T1 + sched->run_measurement_overhead < T0 + nsecs);
}

static void sleep_nsecs(u64 nsecs)
{
	struct timespec ts;

	ts.tv_nsec = nsecs % 999999999;
	ts.tv_sec = nsecs / 999999999;

	nanosleep(&ts, NULL);
}

static void calibrate_run_measurement_overhead(struct perf_sched *sched)
{
	u64 T0, T1, delta, min_delta = 1000000000ULL;
	int i;

	for (i = 0; i < 10; i++) {
		T0 = get_nsecs();
		burn_nsecs(sched, 0);
		T1 = get_nsecs();
		delta = T1-T0;
		min_delta = min(min_delta, delta);
	}
	sched->run_measurement_overhead = min_delta;

	printf("run measurement overhead: %" PRIu64 " nsecs\n", min_delta);
}

static void calibrate_sleep_measurement_overhead(struct perf_sched *sched)
{
	u64 T0, T1, delta, min_delta = 1000000000ULL;
	int i;

	for (i = 0; i < 10; i++) {
		T0 = get_nsecs();
		sleep_nsecs(10000);
		T1 = get_nsecs();
		delta = T1-T0;
		min_delta = min(min_delta, delta);
	}
	min_delta -= 10000;
	sched->sleep_measurement_overhead = min_delta;

	printf("sleep measurement overhead: %" PRIu64 " nsecs\n", min_delta);
}

static struct sched_atom *
get_new_event(struct task_desc *task, u64 timestamp)
{
	struct sched_atom *event = zalloc(sizeof(*event));
	unsigned long idx = task->nr_events;
	size_t size;

	event->timestamp = timestamp;
	event->nr = idx;

	task->nr_events++;
	size = sizeof(struct sched_atom *) * task->nr_events;
	task->atoms = realloc(task->atoms, size);
	BUG_ON(!task->atoms);

	task->atoms[idx] = event;

	return event;
}

static struct sched_atom *last_event(struct task_desc *task)
{
	if (!task->nr_events)
		return NULL;

	return task->atoms[task->nr_events - 1];
}

static void add_sched_event_run(struct perf_sched *sched, struct task_desc *task,
				u64 timestamp, u64 duration)
{
	struct sched_atom *event, *curr_event = last_event(task);

	/*
	 * optimize an existing RUN event by merging this one
	 * to it:
	 */
	if (curr_event && curr_event->type == SCHED_EVENT_RUN) {
		sched->nr_run_events_optimized++;
		curr_event->duration += duration;
		return;
	}
	event = get_new_event(task, timestamp);

	event->type = SCHED_EVENT_RUN;
	event->duration = duration;

	sched->nr_run_events++;
}

static void add_sched_event_wakeup(struct perf_sched *sched, struct task_desc *task,
				   u64 timestamp, struct task_desc *wakee)
{
	struct sched_atom *event, *wakee_event;

	event = get_new_event(task, timestamp);
	event->type = SCHED_EVENT_WAKEUP;
	event->wakee = wakee;

	wakee_event = last_event(wakee);
	if (!wakee_event || wakee_event->type != SCHED_EVENT_SLEEP) {
		sched->targetless_wakeups++;
		return;
	}
	if (wakee_event->wait_sem) {
		sched->multitarget_wakeups++;
		return;
	}

	wakee_event->wait_sem = zalloc(sizeof(*wakee_event->wait_sem));
	sem_init(wakee_event->wait_sem, 0, 0);
	wakee_event->specific_wait = 1;
	event->wait_sem = wakee_event->wait_sem;

	sched->nr_wakeup_events++;
}

static void add_sched_event_sleep(struct perf_sched *sched, struct task_desc *task,
				  u64 timestamp, u64 task_state __maybe_unused)
{
	struct sched_atom *event = get_new_event(task, timestamp);

	event->type = SCHED_EVENT_SLEEP;

	sched->nr_sleep_events++;
}

static struct task_desc *register_pid(struct perf_sched *sched,
				      unsigned long pid, const char *comm)
{
	struct task_desc *task;
	static int pid_max;

	if (sched->pid_to_task == NULL) {
		if (sysctl__read_int("kernel/pid_max", &pid_max) < 0)
			pid_max = MAX_PID;
		BUG_ON((sched->pid_to_task = calloc(pid_max, sizeof(struct task_desc *))) == NULL);
	}
	if (pid >= (unsigned long)pid_max) {
		BUG_ON((sched->pid_to_task = realloc(sched->pid_to_task, (pid + 1) *
			sizeof(struct task_desc *))) == NULL);
		while (pid >= (unsigned long)pid_max)
			sched->pid_to_task[pid_max++] = NULL;
	}

	task = sched->pid_to_task[pid];

	if (task)
		return task;

	task = zalloc(sizeof(*task));
	task->pid = pid;
	task->nr = sched->nr_tasks;
	strcpy(task->comm, comm);
	/*
	 * every task starts in sleeping state - this gets ignored
	 * if there's no wakeup pointing to this sleep state:
	 */
	add_sched_event_sleep(sched, task, 0, 0);

	sched->pid_to_task[pid] = task;
	sched->nr_tasks++;
	sched->tasks = realloc(sched->tasks, sched->nr_tasks * sizeof(struct task_desc *));
	BUG_ON(!sched->tasks);
	sched->tasks[task->nr] = task;

	if (verbose)
		printf("registered task #%ld, PID %ld (%s)\n", sched->nr_tasks, pid, comm);

	return task;
}


static void print_task_traces(struct perf_sched *sched)
{
	struct task_desc *task;
	unsigned long i;

	for (i = 0; i < sched->nr_tasks; i++) {
		task = sched->tasks[i];
		printf("task %6ld (%20s:%10ld), nr_events: %ld\n",
			task->nr, task->comm, task->pid, task->nr_events);
	}
}

static void add_cross_task_wakeups(struct perf_sched *sched)
{
	struct task_desc *task1, *task2;
	unsigned long i, j;

	for (i = 0; i < sched->nr_tasks; i++) {
		task1 = sched->tasks[i];
		j = i + 1;
		if (j == sched->nr_tasks)
			j = 0;
		task2 = sched->tasks[j];
		add_sched_event_wakeup(sched, task1, 0, task2);
	}
}

static void perf_sched__process_event(struct perf_sched *sched,
				      struct sched_atom *atom)
{
	int ret = 0;

	switch (atom->type) {
		case SCHED_EVENT_RUN:
			burn_nsecs(sched, atom->duration);
			break;
		case SCHED_EVENT_SLEEP:
			if (atom->wait_sem)
				ret = sem_wait(atom->wait_sem);
			BUG_ON(ret);
			break;
		case SCHED_EVENT_WAKEUP:
			if (atom->wait_sem)
				ret = sem_post(atom->wait_sem);
			BUG_ON(ret);
			break;
		case SCHED_EVENT_MIGRATION:
			break;
		default:
			BUG_ON(1);
	}
}

static u64 get_cpu_usage_nsec_parent(void)
{
	struct rusage ru;
	u64 sum;
	int err;

	err = getrusage(RUSAGE_SELF, &ru);
	BUG_ON(err);

	sum =  ru.ru_utime.tv_sec*1e9 + ru.ru_utime.tv_usec*1e3;
	sum += ru.ru_stime.tv_sec*1e9 + ru.ru_stime.tv_usec*1e3;

	return sum;
}

static int self_open_counters(void)
{
	struct perf_event_attr attr;
	char sbuf[STRERR_BUFSIZE];
	int fd;

	memset(&attr, 0, sizeof(attr));

	attr.type = PERF_TYPE_SOFTWARE;
	attr.config = PERF_COUNT_SW_TASK_CLOCK;

	fd = sys_perf_event_open(&attr, 0, -1, -1,
				 perf_event_open_cloexec_flag());

	if (fd < 0) {
		pr_err("Error: sys_perf_event_open() syscall returned "
		       "with %d (%s)\n", fd,
		       strerror_r(errno, sbuf, sizeof(sbuf)));
		exit(EXIT_FAILURE);
	}
	return fd;
}

static u64 get_cpu_usage_nsec_self(int fd)
{
	u64 runtime;
	int ret;

	ret = read(fd, &runtime, sizeof(runtime));
	BUG_ON(ret != sizeof(runtime));

	return runtime;
}

struct sched_thread_parms {
	struct task_desc  *task;
	struct perf_sched *sched;
	int fd;
};

static void *thread_func(void *ctx)
{
	struct sched_thread_parms *parms = ctx;
	struct task_desc *this_task = parms->task;
	struct perf_sched *sched = parms->sched;
	u64 cpu_usage_0, cpu_usage_1;
	unsigned long i, ret;
	char comm2[22];
	int fd = parms->fd;

	zfree(&parms);

	sprintf(comm2, ":%s", this_task->comm);
	prctl(PR_SET_NAME, comm2);
	if (fd < 0)
		return NULL;
again:
	ret = sem_post(&this_task->ready_for_work);
	BUG_ON(ret);
	ret = pthread_mutex_lock(&sched->start_work_mutex);
	BUG_ON(ret);
	ret = pthread_mutex_unlock(&sched->start_work_mutex);
	BUG_ON(ret);

	cpu_usage_0 = get_cpu_usage_nsec_self(fd);

	for (i = 0; i < this_task->nr_events; i++) {
		this_task->curr_event = i;
		perf_sched__process_event(sched, this_task->atoms[i]);
	}

	cpu_usage_1 = get_cpu_usage_nsec_self(fd);
	this_task->cpu_usage = cpu_usage_1 - cpu_usage_0;
	ret = sem_post(&this_task->work_done_sem);
	BUG_ON(ret);

	ret = pthread_mutex_lock(&sched->work_done_wait_mutex);
	BUG_ON(ret);
	ret = pthread_mutex_unlock(&sched->work_done_wait_mutex);
	BUG_ON(ret);

	goto again;
}

static void create_tasks(struct perf_sched *sched)
{
	struct task_desc *task;
	pthread_attr_t attr;
	unsigned long i;
	int err;

	err = pthread_attr_init(&attr);
	BUG_ON(err);
	err = pthread_attr_setstacksize(&attr,
			(size_t) max(16 * 1024, PTHREAD_STACK_MIN));
	BUG_ON(err);
	err = pthread_mutex_lock(&sched->start_work_mutex);
	BUG_ON(err);
	err = pthread_mutex_lock(&sched->work_done_wait_mutex);
	BUG_ON(err);
	for (i = 0; i < sched->nr_tasks; i++) {
		struct sched_thread_parms *parms = malloc(sizeof(*parms));
		BUG_ON(parms == NULL);
		parms->task = task = sched->tasks[i];
		parms->sched = sched;
		parms->fd = self_open_counters();
		sem_init(&task->sleep_sem, 0, 0);
		sem_init(&task->ready_for_work, 0, 0);
		sem_init(&task->work_done_sem, 0, 0);
		task->curr_event = 0;
		err = pthread_create(&task->thread, &attr, thread_func, parms);
		BUG_ON(err);
	}
}

static void wait_for_tasks(struct perf_sched *sched)
{
	u64 cpu_usage_0, cpu_usage_1;
	struct task_desc *task;
	unsigned long i, ret;
	sched->start_time = get_nsecs();
	sched->cpu_usage = 0;
	pthread_mutex_unlock(&sched->work_done_wait_mutex);

	for (i = 0; i < sched->nr_tasks; i++) {
		task = sched->tasks[i];
		ret = sem_wait(&task->ready_for_work);
		BUG_ON(ret);
		sem_init(&task->ready_for_work, 0, 0);
	}
	ret = pthread_mutex_lock(&sched->work_done_wait_mutex);
	BUG_ON(ret);

	cpu_usage_0 = get_cpu_usage_nsec_parent();

	pthread_mutex_unlock(&sched->start_work_mutex);

	for (i = 0; i < sched->nr_tasks; i++) {
		task = sched->tasks[i];
		ret = sem_wait(&task->work_done_sem);
		BUG_ON(ret);
		sem_init(&task->work_done_sem, 0, 0);
		sched->cpu_usage += task->cpu_usage;
		task->cpu_usage = 0;
	}

	cpu_usage_1 = get_cpu_usage_nsec_parent();
	if (!sched->runavg_cpu_usage)
		sched->runavg_cpu_usage = sched->cpu_usage;
	sched->runavg_cpu_usage = (sched->runavg_cpu_usage * 9 + sched->cpu_usage) / 10;

	sched->parent_cpu_usage = cpu_usage_1 - cpu_usage_0;
	if (!sched->runavg_parent_cpu_usage)
		sched->runavg_parent_cpu_usage = sched->parent_cpu_usage;
	sched->runavg_parent_cpu_usage = (sched->runavg_parent_cpu_usage * 9 +
					 sched->parent_cpu_usage)/10;

	ret = pthread_mutex_lock(&sched->start_work_mutex);
	BUG_ON(ret);

	for (i = 0; i < sched->nr_tasks; i++) {
		task = sched->tasks[i];
		sem_init(&task->sleep_sem, 0, 0);
		task->curr_event = 0;
	}
}

static void run_one_test(struct perf_sched *sched)
{
	u64 T0, T1, delta, avg_delta, fluct;

	T0 = get_nsecs();
	wait_for_tasks(sched);
	T1 = get_nsecs();

	delta = T1 - T0;
	sched->sum_runtime += delta;
	sched->nr_runs++;

	avg_delta = sched->sum_runtime / sched->nr_runs;
	if (delta < avg_delta)
		fluct = avg_delta - delta;
	else
		fluct = delta - avg_delta;
	sched->sum_fluct += fluct;
	if (!sched->run_avg)
		sched->run_avg = delta;
	sched->run_avg = (sched->run_avg * 9 + delta) / 10;

	printf("#%-3ld: %0.3f, ", sched->nr_runs, (double)delta / 1000000.0);

	printf("ravg: %0.2f, ", (double)sched->run_avg / 1e6);

	printf("cpu: %0.2f / %0.2f",
		(double)sched->cpu_usage / 1e6, (double)sched->runavg_cpu_usage / 1e6);

#if 0
	/*
	 * rusage statistics done by the parent, these are less
	 * accurate than the sched->sum_exec_runtime based statistics:
	 */
	printf(" [%0.2f / %0.2f]",
		(double)sched->parent_cpu_usage/1e6,
		(double)sched->runavg_parent_cpu_usage/1e6);
#endif

	printf("\n");

	if (sched->nr_sleep_corrections)
		printf(" (%ld sleep corrections)\n", sched->nr_sleep_corrections);
	sched->nr_sleep_corrections = 0;
}

static void test_calibrations(struct perf_sched *sched)
{
	u64 T0, T1;

	T0 = get_nsecs();
	burn_nsecs(sched, 1e6);
	T1 = get_nsecs();

	printf("the run test took %" PRIu64 " nsecs\n", T1 - T0);

	T0 = get_nsecs();
	sleep_nsecs(1e6);
	T1 = get_nsecs();

	printf("the sleep test took %" PRIu64 " nsecs\n", T1 - T0);
}

static int
replay_wakeup_event(struct perf_sched *sched,
		    struct perf_evsel *evsel, struct perf_sample *sample,
		    struct machine *machine __maybe_unused)
{
	const char *comm = perf_evsel__strval(evsel, sample, "comm");
	const u32 pid	 = perf_evsel__intval(evsel, sample, "pid");
	struct task_desc *waker, *wakee;

	if (verbose) {
		printf("sched_wakeup event %p\n", evsel);

		printf(" ... pid %d woke up %s/%d\n", sample->tid, comm, pid);
	}

	waker = register_pid(sched, sample->tid, "<unknown>");
	wakee = register_pid(sched, pid, comm);

	add_sched_event_wakeup(sched, waker, sample->time, wakee);
	return 0;
}

static int replay_switch_event(struct perf_sched *sched,
			       struct perf_evsel *evsel,
			       struct perf_sample *sample,
			       struct machine *machine __maybe_unused)
{
	const char *prev_comm  = perf_evsel__strval(evsel, sample, "prev_comm"),
		   *next_comm  = perf_evsel__strval(evsel, sample, "next_comm");
	const u32 prev_pid = perf_evsel__intval(evsel, sample, "prev_pid"),
		  next_pid = perf_evsel__intval(evsel, sample, "next_pid");
	const u64 prev_state = perf_evsel__intval(evsel, sample, "prev_state");
	struct task_desc *prev, __maybe_unused *next;
	u64 timestamp0, timestamp = sample->time;
	int cpu = sample->cpu;
	s64 delta;

	if (verbose)
		printf("sched_switch event %p\n", evsel);

	if (cpu >= MAX_CPUS || cpu < 0)
		return 0;

	timestamp0 = sched->cpu_last_switched[cpu];
	if (timestamp0)
		delta = timestamp - timestamp0;
	else
		delta = 0;

	if (delta < 0) {
		pr_err("hm, delta: %" PRIu64 " < 0 ?\n", delta);
		return -1;
	}

	pr_debug(" ... switch from %s/%d to %s/%d [ran %" PRIu64 " nsecs]\n",
		 prev_comm, prev_pid, next_comm, next_pid, delta);

	prev = register_pid(sched, prev_pid, prev_comm);
	next = register_pid(sched, next_pid, next_comm);

	sched->cpu_last_switched[cpu] = timestamp;

	add_sched_event_run(sched, prev, timestamp, delta);
	add_sched_event_sleep(sched, prev, timestamp, prev_state);

	return 0;
}

static int replay_fork_event(struct perf_sched *sched,
			     union perf_event *event,
			     struct machine *machine)
{
	struct thread *child, *parent;

	child = machine__findnew_thread(machine, event->fork.pid,
					event->fork.tid);
	parent = machine__findnew_thread(machine, event->fork.ppid,
					 event->fork.ptid);

	if (child == NULL || parent == NULL) {
		pr_debug("thread does not exist on fork event: child %p, parent %p\n",
				 child, parent);
		return 0;
	}

	if (verbose) {
		printf("fork event\n");
		printf("... parent: %s/%d\n", thread__comm_str(parent), parent->tid);
		printf("...  child: %s/%d\n", thread__comm_str(child), child->tid);
	}

	register_pid(sched, parent->tid, thread__comm_str(parent));
	register_pid(sched, child->tid, thread__comm_str(child));
	return 0;
}

struct sort_dimension {
	const char		*name;
	sort_fn_t		cmp;
	struct list_head	list;
};

static int
thread_lat_cmp(struct list_head *list, struct work_atoms *l, struct work_atoms *r)
{
	struct sort_dimension *sort;
	int ret = 0;

	BUG_ON(list_empty(list));

	list_for_each_entry(sort, list, list) {
		ret = sort->cmp(l, r);
		if (ret)
			return ret;
	}

	return ret;
}

static struct work_atoms *
thread_atoms_search(struct rb_root *root, struct thread *thread,
			 struct list_head *sort_list)
{
	struct rb_node *node = root->rb_node;
	struct work_atoms key = { .thread = thread };

	while (node) {
		struct work_atoms *atoms;
		int cmp;

		atoms = container_of(node, struct work_atoms, node);

		cmp = thread_lat_cmp(sort_list, &key, atoms);
		if (cmp > 0)
			node = node->rb_left;
		else if (cmp < 0)
			node = node->rb_right;
		else {
			BUG_ON(thread != atoms->thread);
			return atoms;
		}
	}
	return NULL;
}

static void
__thread_latency_insert(struct rb_root *root, struct work_atoms *data,
			 struct list_head *sort_list)
{
	struct rb_node **new = &(root->rb_node), *parent = NULL;

	while (*new) {
		struct work_atoms *this;
		int cmp;

		this = container_of(*new, struct work_atoms, node);
		parent = *new;

		cmp = thread_lat_cmp(sort_list, data, this);

		if (cmp > 0)
			new = &((*new)->rb_left);
		else
			new = &((*new)->rb_right);
	}

	rb_link_node(&data->node, parent, new);
	rb_insert_color(&data->node, root);
}
static int thread_atoms_insert(struct perf_sched *sched, struct thread *thread)
{
	struct work_atoms *atoms = zalloc(sizeof(*atoms));
	if (!atoms) {
		pr_err("No memory at %s\n", __func__);
		return -1;
	}

	atoms->thread = thread__get(thread);
	INIT_LIST_HEAD(&atoms->work_list);
	__thread_latency_insert(&sched->atom_root, atoms, &sched->cmp_pid);
	return 0;
}

static char sched_out_state(u64 prev_state)
{
	const char *str = TASK_STATE_TO_CHAR_STR;

	return str[prev_state];
}

static int
add_sched_out_event(struct work_atoms *atoms,
		    char run_state,
		    u64 timestamp)
{
	struct work_atom *atom = zalloc(sizeof(*atom));
	if (!atom) {
		pr_err("Non memory at %s", __func__);
		return -1;
	}

	atom->sched_out_time = timestamp;

	if (run_state == 'R') {
		atom->state = THREAD_WAIT_CPU;
		atom->wake_up_time = atom->sched_out_time;
	}

	list_add_tail(&atom->list, &atoms->work_list);
	return 0;
}

static void
add_runtime_event(struct work_atoms *atoms, u64 delta,
		  u64 timestamp __maybe_unused)
{
	struct work_atom *atom;

	BUG_ON(list_empty(&atoms->work_list));

	atom = list_entry(atoms->work_list.prev, struct work_atom, list);

	atom->runtime += delta;
	atoms->total_runtime += delta;
}

static void
add_sched_in_event(struct work_atoms *atoms, u64 timestamp)
{
	struct work_atom *atom;
	u64 delta;

	if (list_empty(&atoms->work_list))
		return;

	atom = list_entry(atoms->work_list.prev, struct work_atom, list);

	if (atom->state != THREAD_WAIT_CPU)
		return;

	if (timestamp < atom->wake_up_time) {
		atom->state = THREAD_IGNORE;
		return;
	}

	atom->state = THREAD_SCHED_IN;
	atom->sched_in_time = timestamp;

	delta = atom->sched_in_time - atom->wake_up_time;
	atoms->total_lat += delta;
	if (delta > atoms->max_lat) {
		atoms->max_lat = delta;
		atoms->max_lat_at = timestamp;
	}
	atoms->nb_atoms++;
}

static int latency_switch_event(struct perf_sched *sched,
				struct perf_evsel *evsel,
				struct perf_sample *sample,
				struct machine *machine)
{
	const u32 prev_pid = perf_evsel__intval(evsel, sample, "prev_pid"),
		  next_pid = perf_evsel__intval(evsel, sample, "next_pid");
	const u64 prev_state = perf_evsel__intval(evsel, sample, "prev_state");
	struct work_atoms *out_events, *in_events;
	struct thread *sched_out, *sched_in;
	u64 timestamp0, timestamp = sample->time;
	int cpu = sample->cpu;
	s64 delta;

	BUG_ON(cpu >= MAX_CPUS || cpu < 0);

	timestamp0 = sched->cpu_last_switched[cpu];
	sched->cpu_last_switched[cpu] = timestamp;
	if (timestamp0)
		delta = timestamp - timestamp0;
	else
		delta = 0;

	if (delta < 0) {
		pr_err("hm, delta: %" PRIu64 " < 0 ?\n", delta);
		return -1;
	}

	sched_out = machine__findnew_thread(machine, -1, prev_pid);
	sched_in = machine__findnew_thread(machine, -1, next_pid);

	out_events = thread_atoms_search(&sched->atom_root, sched_out, &sched->cmp_pid);
	if (!out_events) {
		if (thread_atoms_insert(sched, sched_out))
			return -1;
		out_events = thread_atoms_search(&sched->atom_root, sched_out, &sched->cmp_pid);
		if (!out_events) {
			pr_err("out-event: Internal tree error");
			return -1;
		}
	}
	if (add_sched_out_event(out_events, sched_out_state(prev_state), timestamp))
		return -1;

	in_events = thread_atoms_search(&sched->atom_root, sched_in, &sched->cmp_pid);
	if (!in_events) {
		if (thread_atoms_insert(sched, sched_in))
			return -1;
		in_events = thread_atoms_search(&sched->atom_root, sched_in, &sched->cmp_pid);
		if (!in_events) {
			pr_err("in-event: Internal tree error");
			return -1;
		}
		/*
		 * Take came in we have not heard about yet,
		 * add in an initial atom in runnable state:
		 */
		if (add_sched_out_event(in_events, 'R', timestamp))
			return -1;
	}
	add_sched_in_event(in_events, timestamp);

	return 0;
}

static int latency_runtime_event(struct perf_sched *sched,
				 struct perf_evsel *evsel,
				 struct perf_sample *sample,
				 struct machine *machine)
{
	const u32 pid	   = perf_evsel__intval(evsel, sample, "pid");
	const u64 runtime  = perf_evsel__intval(evsel, sample, "runtime");
	struct thread *thread = machine__findnew_thread(machine, -1, pid);
	struct work_atoms *atoms = thread_atoms_search(&sched->atom_root, thread, &sched->cmp_pid);
	u64 timestamp = sample->time;
	int cpu = sample->cpu;

	BUG_ON(cpu >= MAX_CPUS || cpu < 0);
	if (!atoms) {
		if (thread_atoms_insert(sched, thread))
			return -1;
		atoms = thread_atoms_search(&sched->atom_root, thread, &sched->cmp_pid);
		if (!atoms) {
			pr_err("in-event: Internal tree error");
			return -1;
		}
		if (add_sched_out_event(atoms, 'R', timestamp))
			return -1;
	}

	add_runtime_event(atoms, runtime, timestamp);
	return 0;
}

static int latency_wakeup_event(struct perf_sched *sched,
				struct perf_evsel *evsel,
				struct perf_sample *sample,
				struct machine *machine)
{
	const u32 pid	  = perf_evsel__intval(evsel, sample, "pid");
	struct work_atoms *atoms;
	struct work_atom *atom;
	struct thread *wakee;
	u64 timestamp = sample->time;

	wakee = machine__findnew_thread(machine, -1, pid);
	atoms = thread_atoms_search(&sched->atom_root, wakee, &sched->cmp_pid);
	if (!atoms) {
		if (thread_atoms_insert(sched, wakee))
			return -1;
		atoms = thread_atoms_search(&sched->atom_root, wakee, &sched->cmp_pid);
		if (!atoms) {
			pr_err("wakeup-event: Internal tree error");
			return -1;
		}
		if (add_sched_out_event(atoms, 'S', timestamp))
			return -1;
	}

	BUG_ON(list_empty(&atoms->work_list));

	atom = list_entry(atoms->work_list.prev, struct work_atom, list);

	/*
	 * As we do not guarantee the wakeup event happens when
	 * task is out of run queue, also may happen when task is
	 * on run queue and wakeup only change ->state to TASK_RUNNING,
	 * then we should not set the ->wake_up_time when wake up a
	 * task which is on run queue.
	 *
	 * You WILL be missing events if you've recorded only
	 * one CPU, or are only looking at only one, so don't
	 * skip in this case.
	 */
	if (sched->profile_cpu == -1 && atom->state != THREAD_SLEEPING)
		return 0;

	sched->nr_timestamps++;
	if (atom->sched_out_time > timestamp) {
		sched->nr_unordered_timestamps++;
		return 0;
	}

	atom->state = THREAD_WAIT_CPU;
	atom->wake_up_time = timestamp;
	return 0;
}

static int latency_migrate_task_event(struct perf_sched *sched,
				      struct perf_evsel *evsel,
				      struct perf_sample *sample,
				      struct machine *machine)
{
	const u32 pid = perf_evsel__intval(evsel, sample, "pid");
	u64 timestamp = sample->time;
	struct work_atoms *atoms;
	struct work_atom *atom;
	struct thread *migrant;

	/*
	 * Only need to worry about migration when profiling one CPU.
	 */
	if (sched->profile_cpu == -1)
		return 0;

	migrant = machine__findnew_thread(machine, -1, pid);
	atoms = thread_atoms_search(&sched->atom_root, migrant, &sched->cmp_pid);
	if (!atoms) {
		if (thread_atoms_insert(sched, migrant))
			return -1;
		register_pid(sched, migrant->tid, thread__comm_str(migrant));
		atoms = thread_atoms_search(&sched->atom_root, migrant, &sched->cmp_pid);
		if (!atoms) {
			pr_err("migration-event: Internal tree error");
			return -1;
		}
		if (add_sched_out_event(atoms, 'R', timestamp))
			return -1;
	}

	BUG_ON(list_empty(&atoms->work_list));

	atom = list_entry(atoms->work_list.prev, struct work_atom, list);
	atom->sched_in_time = atom->sched_out_time = atom->wake_up_time = timestamp;

	sched->nr_timestamps++;

	if (atom->sched_out_time > timestamp)
		sched->nr_unordered_timestamps++;

	return 0;
}

static void output_lat_thread(struct perf_sched *sched, struct work_atoms *work_list)
{
	int i;
	int ret;
	u64 avg;

	if (!work_list->nb_atoms)
		return;
	/*
	 * Ignore idle threads:
	 */
	if (!strcmp(thread__comm_str(work_list->thread), "swapper"))
		return;

	sched->all_runtime += work_list->total_runtime;
	sched->all_count   += work_list->nb_atoms;

	ret = printf("  %s:%d ", thread__comm_str(work_list->thread), work_list->thread->tid);

	for (i = 0; i < 24 - ret; i++)
		printf(" ");

	avg = work_list->total_lat / work_list->nb_atoms;

	printf("|%11.3f ms |%9" PRIu64 " | avg:%9.3f ms | max:%9.3f ms | max at: %13.6f s\n",
	      (double)work_list->total_runtime / 1e6,
		 work_list->nb_atoms, (double)avg / 1e6,
		 (double)work_list->max_lat / 1e6,
		 (double)work_list->max_lat_at / 1e9);
}

static int pid_cmp(struct work_atoms *l, struct work_atoms *r)
{
	if (l->thread->tid < r->thread->tid)
		return -1;
	if (l->thread->tid > r->thread->tid)
		return 1;

	return 0;
}

static int avg_cmp(struct work_atoms *l, struct work_atoms *r)
{
	u64 avgl, avgr;

	if (!l->nb_atoms)
		return -1;

	if (!r->nb_atoms)
		return 1;

	avgl = l->total_lat / l->nb_atoms;
	avgr = r->total_lat / r->nb_atoms;

	if (avgl < avgr)
		return -1;
	if (avgl > avgr)
		return 1;

	return 0;
}

static int max_cmp(struct work_atoms *l, struct work_atoms *r)
{
	if (l->max_lat < r->max_lat)
		return -1;
	if (l->max_lat > r->max_lat)
		return 1;
	return 0;
}

static int switch_cmp(struct work_atoms *l, struct work_atoms *r)
{
	if (l->nb_atoms < r->nb_atoms)
		return -1;
	if (l->nb_atoms > r->nb_atoms)
		return 1;

	return 0;
}

static int runtime_cmp(struct work_atoms *l, struct work_atoms *r)
{
	if (l->total_runtime < r->total_runtime)
		return -1;
	if (l->total_runtime > r->total_runtime)
		return 1;

	return 0;
}

static int sort_dimension__add(const char *tok, struct list_head *list)
{
	size_t i;
	static struct sort_dimension avg_sort_dimension = {
		.name = "avg",
		.cmp  = avg_cmp,
	};
	static struct sort_dimension max_sort_dimension = {
		.name = "max",
		.cmp  = max_cmp,
	};
	static struct sort_dimension pid_sort_dimension = {
		.name = "pid",
		.cmp  = pid_cmp,
	};
	static struct sort_dimension runtime_sort_dimension = {
		.name = "runtime",
		.cmp  = runtime_cmp,
	};
	static struct sort_dimension switch_sort_dimension = {
		.name = "switch",
		.cmp  = switch_cmp,
	};
	struct sort_dimension *available_sorts[] = {
		&pid_sort_dimension,
		&avg_sort_dimension,
		&max_sort_dimension,
		&switch_sort_dimension,
		&runtime_sort_dimension,
	};

	for (i = 0; i < ARRAY_SIZE(available_sorts); i++) {
		if (!strcmp(available_sorts[i]->name, tok)) {
			list_add_tail(&available_sorts[i]->list, list);

			return 0;
		}
	}

	return -1;
}

static void perf_sched__sort_lat(struct perf_sched *sched)
{
	struct rb_node *node;

	for (;;) {
		struct work_atoms *data;
		node = rb_first(&sched->atom_root);
		if (!node)
			break;

		rb_erase(node, &sched->atom_root);
		data = rb_entry(node, struct work_atoms, node);
		__thread_latency_insert(&sched->sorted_atom_root, data, &sched->sort_list);
	}
}

static int process_sched_wakeup_event(struct perf_tool *tool,
				      struct perf_evsel *evsel,
				      struct perf_sample *sample,
				      struct machine *machine)
{
	struct perf_sched *sched = container_of(tool, struct perf_sched, tool);

	if (sched->tp_handler->wakeup_event)
		return sched->tp_handler->wakeup_event(sched, evsel, sample, machine);

	return 0;
}

static int map_switch_event(struct perf_sched *sched, struct perf_evsel *evsel,
			    struct perf_sample *sample, struct machine *machine)
{
	const u32 next_pid = perf_evsel__intval(evsel, sample, "next_pid");
	struct thread *sched_in;
	int new_shortname;
	u64 timestamp0, timestamp = sample->time;
	s64 delta;
	int cpu, this_cpu = sample->cpu;

	BUG_ON(this_cpu >= MAX_CPUS || this_cpu < 0);

	if (this_cpu > sched->max_cpu)
		sched->max_cpu = this_cpu;

	timestamp0 = sched->cpu_last_switched[this_cpu];
	sched->cpu_last_switched[this_cpu] = timestamp;
	if (timestamp0)
		delta = timestamp - timestamp0;
	else
		delta = 0;

	if (delta < 0) {
		pr_err("hm, delta: %" PRIu64 " < 0 ?\n", delta);
		return -1;
	}

	sched_in = machine__findnew_thread(machine, -1, next_pid);

	sched->curr_thread[this_cpu] = sched_in;

	printf("  ");

	new_shortname = 0;
	if (!sched_in->shortname[0]) {
		if (!strcmp(thread__comm_str(sched_in), "swapper")) {
			/*
			 * Don't allocate a letter-number for swapper:0
			 * as a shortname. Instead, we use '.' for it.
			 */
			sched_in->shortname[0] = '.';
			sched_in->shortname[1] = ' ';
		} else {
			sched_in->shortname[0] = sched->next_shortname1;
			sched_in->shortname[1] = sched->next_shortname2;
			if (sched->next_shortname1 < 'Z') {
				sched->next_shortname1++;
			} else {
				sched->next_shortname1 = 'A';
				if (sched->next_shortname2 < '9')
					sched->next_shortname2++;
				else
					sched->next_shortname2 = '0';
			}
		}
		new_shortname = 1;
	}

	for (cpu = 0; cpu <= sched->max_cpu; cpu++) {
		if (cpu != this_cpu)
			printf(" ");
		else
			printf("*");

		if (sched->curr_thread[cpu])
			printf("%2s ", sched->curr_thread[cpu]->shortname);
		else
			printf("   ");
	}

	printf("  %12.6f secs ", (double)timestamp/1e9);
	if (new_shortname) {
		printf("%s => %s:%d\n",
		       sched_in->shortname, thread__comm_str(sched_in), sched_in->tid);
	} else {
		printf("\n");
	}

	return 0;
}

static int process_sched_switch_event(struct perf_tool *tool,
				      struct perf_evsel *evsel,
				      struct perf_sample *sample,
				      struct machine *machine)
{
	struct perf_sched *sched = container_of(tool, struct perf_sched, tool);
	int this_cpu = sample->cpu, err = 0;
	u32 prev_pid = perf_evsel__intval(evsel, sample, "prev_pid"),
	    next_pid = perf_evsel__intval(evsel, sample, "next_pid");

	if (sched->curr_pid[this_cpu] != (u32)-1) {
		/*
		 * Are we trying to switch away a PID that is
		 * not current?
		 */
		if (sched->curr_pid[this_cpu] != prev_pid)
			sched->nr_context_switch_bugs++;
	}

	if (sched->tp_handler->switch_event)
		err = sched->tp_handler->switch_event(sched, evsel, sample, machine);

	sched->curr_pid[this_cpu] = next_pid;
	return err;
}

static int process_sched_runtime_event(struct perf_tool *tool,
				       struct perf_evsel *evsel,
				       struct perf_sample *sample,
				       struct machine *machine)
{
	struct perf_sched *sched = container_of(tool, struct perf_sched, tool);

	if (sched->tp_handler->runtime_event)
		return sched->tp_handler->runtime_event(sched, evsel, sample, machine);

	return 0;
}

static int perf_sched__process_fork_event(struct perf_tool *tool,
					  union perf_event *event,
					  struct perf_sample *sample,
					  struct machine *machine)
{
	struct perf_sched *sched = container_of(tool, struct perf_sched, tool);

	/* run the fork event through the perf machineruy */
	perf_event__process_fork(tool, event, sample, machine);

	/* and then run additional processing needed for this command */
	if (sched->tp_handler->fork_event)
		return sched->tp_handler->fork_event(sched, event, machine);

	return 0;
}

static int process_sched_migrate_task_event(struct perf_tool *tool,
					    struct perf_evsel *evsel,
					    struct perf_sample *sample,
					    struct machine *machine)
{
	struct perf_sched *sched = container_of(tool, struct perf_sched, tool);

	if (sched->tp_handler->migrate_task_event)
		return sched->tp_handler->migrate_task_event(sched, evsel, sample, machine);

	return 0;
}

typedef int (*tracepoint_handler)(struct perf_tool *tool,
				  struct perf_evsel *evsel,
				  struct perf_sample *sample,
				  struct machine *machine);

static int perf_sched__process_tracepoint_sample(struct perf_tool *tool __maybe_unused,
						 union perf_event *event __maybe_unused,
						 struct perf_sample *sample,
						 struct perf_evsel *evsel,
						 struct machine *machine)
{
	int err = 0;

	if (evsel->handler != NULL) {
		tracepoint_handler f = evsel->handler;
		err = f(tool, evsel, sample, machine);
	}

	return err;
}

static int perf_sched__read_events(struct perf_sched *sched)
{
	const struct perf_evsel_str_handler handlers[] = {
		{ "sched:sched_switch",	      process_sched_switch_event, },
		{ "sched:sched_stat_runtime", process_sched_runtime_event, },
		{ "sched:sched_wakeup",	      process_sched_wakeup_event, },
		{ "sched:sched_wakeup_new",   process_sched_wakeup_event, },
		{ "sched:sched_migrate_task", process_sched_migrate_task_event, },
	};
	struct perf_session *session;
	struct perf_data_file file = {
		.path = input_name,
		.mode = PERF_DATA_MODE_READ,
	};
	int rc = -1;

	session = perf_session__new(&file, false, &sched->tool);
	if (session == NULL) {
		pr_debug("No Memory for session\n");
		return -1;
	}

	symbol__init(&session->header.env);

	if (perf_session__set_tracepoints_handlers(session, handlers))
		goto out_delete;

	if (perf_session__has_traces(session, "record -R")) {
		int err = perf_session__process_events(session);
		if (err) {
			pr_err("Failed to process events, error %d", err);
			goto out_delete;
		}

		sched->nr_events      = session->evlist->stats.nr_events[0];
		sched->nr_lost_events = session->evlist->stats.total_lost;
		sched->nr_lost_chunks = session->evlist->stats.nr_events[PERF_RECORD_LOST];
	}

	rc = 0;
out_delete:
	perf_session__delete(session);
	return rc;
}

static void print_bad_events(struct perf_sched *sched)
{
	if (sched->nr_unordered_timestamps && sched->nr_timestamps) {
		printf("  INFO: %.3f%% unordered timestamps (%ld out of %ld)\n",
			(double)sched->nr_unordered_timestamps/(double)sched->nr_timestamps*100.0,
			sched->nr_unordered_timestamps, sched->nr_timestamps);
	}
	if (sched->nr_lost_events && sched->nr_events) {
		printf("  INFO: %.3f%% lost events (%ld out of %ld, in %ld chunks)\n",
			(double)sched->nr_lost_events/(double)sched->nr_events * 100.0,
			sched->nr_lost_events, sched->nr_events, sched->nr_lost_chunks);
	}
	if (sched->nr_context_switch_bugs && sched->nr_timestamps) {
		printf("  INFO: %.3f%% context switch bugs (%ld out of %ld)",
			(double)sched->nr_context_switch_bugs/(double)sched->nr_timestamps*100.0,
			sched->nr_context_switch_bugs, sched->nr_timestamps);
		if (sched->nr_lost_events)
			printf(" (due to lost events?)");
		printf("\n");
	}
}

static int perf_sched__lat(struct perf_sched *sched)
{
	struct rb_node *next;

	setup_pager();

	if (perf_sched__read_events(sched))
		return -1;

	perf_sched__sort_lat(sched);

	printf("\n -----------------------------------------------------------------------------------------------------------------\n");
	printf("  Task                  |   Runtime ms  | Switches | Average delay ms | Maximum delay ms | Maximum delay at       |\n");
	printf(" -----------------------------------------------------------------------------------------------------------------\n");

	next = rb_first(&sched->sorted_atom_root);
	while (next) {
		struct work_atoms *work_list;

		work_list = rb_entry(next, struct work_atoms, node);
		output_lat_thread(sched, work_list);
		next = rb_next(next);
		thread__zput(work_list->thread);
	}

	printf(" -----------------------------------------------------------------------------------------------------------------\n");
	printf("  TOTAL:                |%11.3f ms |%9" PRIu64 " |\n",
		(double)sched->all_runtime / 1e6, sched->all_count);

	printf(" ---------------------------------------------------\n");

	print_bad_events(sched);
	printf("\n");

	return 0;
}

static int perf_sched__map(struct perf_sched *sched)
{
	sched->max_cpu = sysconf(_SC_NPROCESSORS_CONF);

	setup_pager();
	if (perf_sched__read_events(sched))
		return -1;
	print_bad_events(sched);
	return 0;
}

static int perf_sched__replay(struct perf_sched *sched)
{
	unsigned long i;

	calibrate_run_measurement_overhead(sched);
	calibrate_sleep_measurement_overhead(sched);

	test_calibrations(sched);

	if (perf_sched__read_events(sched))
		return -1;

	printf("nr_run_events:        %ld\n", sched->nr_run_events);
	printf("nr_sleep_events:      %ld\n", sched->nr_sleep_events);
	printf("nr_wakeup_events:     %ld\n", sched->nr_wakeup_events);

	if (sched->targetless_wakeups)
		printf("target-less wakeups:  %ld\n", sched->targetless_wakeups);
	if (sched->multitarget_wakeups)
		printf("multi-target wakeups: %ld\n", sched->multitarget_wakeups);
	if (sched->nr_run_events_optimized)
		printf("run atoms optimized: %ld\n",
			sched->nr_run_events_optimized);

	print_task_traces(sched);
	add_cross_task_wakeups(sched);

	create_tasks(sched);
	printf("------------------------------------------------------------\n");
	for (i = 0; i < sched->replay_repeat; i++)
		run_one_test(sched);

	return 0;
}

static void setup_sorting(struct perf_sched *sched, const struct option *options,
			  const char * const usage_msg[])
{
	char *tmp, *tok, *str = strdup(sched->sort_order);

	for (tok = strtok_r(str, ", ", &tmp);
			tok; tok = strtok_r(NULL, ", ", &tmp)) {
		if (sort_dimension__add(tok, &sched->sort_list) < 0) {
			error("Unknown --sort key: `%s'", tok);
			usage_with_options(usage_msg, options);
		}
	}

	free(str);

	sort_dimension__add("pid", &sched->cmp_pid);
}

static int __cmd_record(int argc, const char **argv)
{
	unsigned int rec_argc, i, j;
	const char **rec_argv;
	const char * const record_args[] = {
		"record",
		"-a",
		"-R",
		"-m", "1024",
		"-c", "1",
		"-e", "sched:sched_switch",
		"-e", "sched:sched_stat_wait",
		"-e", "sched:sched_stat_sleep",
		"-e", "sched:sched_stat_iowait",
		"-e", "sched:sched_stat_runtime",
		"-e", "sched:sched_process_fork",
		"-e", "sched:sched_wakeup",
		"-e", "sched:sched_wakeup_new",
		"-e", "sched:sched_migrate_task",
	};

	rec_argc = ARRAY_SIZE(record_args) + argc - 1;
	rec_argv = calloc(rec_argc + 1, sizeof(char *));

	if (rec_argv == NULL)
		return -ENOMEM;

	for (i = 0; i < ARRAY_SIZE(record_args); i++)
		rec_argv[i] = strdup(record_args[i]);

	for (j = 1; j < (unsigned int)argc; j++, i++)
		rec_argv[i] = argv[j];

	BUG_ON(i != rec_argc);

	return cmd_record(i, rec_argv, NULL);
}

int cmd_sched(int argc, const char **argv, const char *prefix __maybe_unused)
{
	const char default_sort_order[] = "avg, max, switch, runtime";
	struct perf_sched sched = {
		.tool = {
			.sample		 = perf_sched__process_tracepoint_sample,
			.comm		 = perf_event__process_comm,
			.lost		 = perf_event__process_lost,
			.fork		 = perf_sched__process_fork_event,
			.ordered_events = true,
		},
		.cmp_pid	      = LIST_HEAD_INIT(sched.cmp_pid),
		.sort_list	      = LIST_HEAD_INIT(sched.sort_list),
		.start_work_mutex     = PTHREAD_MUTEX_INITIALIZER,
		.work_done_wait_mutex = PTHREAD_MUTEX_INITIALIZER,
		.sort_order	      = default_sort_order,
		.replay_repeat	      = 10,
		.profile_cpu	      = -1,
		.next_shortname1      = 'A',
		.next_shortname2      = '0',
	};
	const struct option latency_options[] = {
	OPT_STRING('s', "sort", &sched.sort_order, "key[,key2...]",
		   "sort by key(s): runtime, switch, avg, max"),
	OPT_INCR('v', "verbose", &verbose,
		    "be more verbose (show symbol address, etc)"),
	OPT_INTEGER('C', "CPU", &sched.profile_cpu,
		    "CPU to profile on"),
	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
		    "dump raw trace in ASCII"),
	OPT_END()
	};
	const struct option replay_options[] = {
	OPT_UINTEGER('r', "repeat", &sched.replay_repeat,
		     "repeat the workload replay N times (-1: infinite)"),
	OPT_INCR('v', "verbose", &verbose,
		    "be more verbose (show symbol address, etc)"),
	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
		    "dump raw trace in ASCII"),
	OPT_END()
	};
	const struct option sched_options[] = {
	OPT_STRING('i', "input", &input_name, "file",
		    "input file name"),
	OPT_INCR('v', "verbose", &verbose,
		    "be more verbose (show symbol address, etc)"),
	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
		    "dump raw trace in ASCII"),
	OPT_END()
	};
	const char * const latency_usage[] = {
		"perf sched latency [<options>]",
		NULL
	};
	const char * const replay_usage[] = {
		"perf sched replay [<options>]",
		NULL
	};
	const char *const sched_subcommands[] = { "record", "latency", "map",
						  "replay", "script", NULL };
	const char *sched_usage[] = {
		NULL,
		NULL
	};
	struct trace_sched_handler lat_ops  = {
		.wakeup_event	    = latency_wakeup_event,
		.switch_event	    = latency_switch_event,
		.runtime_event	    = latency_runtime_event,
		.migrate_task_event = latency_migrate_task_event,
	};
	struct trace_sched_handler map_ops  = {
		.switch_event	    = map_switch_event,
	};
	struct trace_sched_handler replay_ops  = {
		.wakeup_event	    = replay_wakeup_event,
		.switch_event	    = replay_switch_event,
		.fork_event	    = replay_fork_event,
	};
	unsigned int i;

	for (i = 0; i < ARRAY_SIZE(sched.curr_pid); i++)
		sched.curr_pid[i] = -1;

	argc = parse_options_subcommand(argc, argv, sched_options, sched_subcommands,
					sched_usage, PARSE_OPT_STOP_AT_NON_OPTION);
	if (!argc)
		usage_with_options(sched_usage, sched_options);

	/*
	 * Aliased to 'perf script' for now:
	 */
	if (!strcmp(argv[0], "script"))
		return cmd_script(argc, argv, prefix);

	if (!strncmp(argv[0], "rec", 3)) {
		return __cmd_record(argc, argv);
	} else if (!strncmp(argv[0], "lat", 3)) {
		sched.tp_handler = &lat_ops;
		if (argc > 1) {
			argc = parse_options(argc, argv, latency_options, latency_usage, 0);
			if (argc)
				usage_with_options(latency_usage, latency_options);
		}
		setup_sorting(&sched, latency_options, latency_usage);
		return perf_sched__lat(&sched);
	} else if (!strcmp(argv[0], "map")) {
		sched.tp_handler = &map_ops;
		setup_sorting(&sched, latency_options, latency_usage);
		return perf_sched__map(&sched);
	} else if (!strncmp(argv[0], "rep", 3)) {
		sched.tp_handler = &replay_ops;
		if (argc) {
			argc = parse_options(argc, argv, replay_options, replay_usage, 0);
			if (argc)
				usage_with_options(replay_usage, replay_options);
		}
		return perf_sched__replay(&sched);
	} else {
		usage_with_options(sched_usage, sched_options);
	}

	return 0;
}