#include "builtin.h"

#include "util/util.h"
#include "util/cache.h"
#include "util/symbol.h"
#include "util/thread.h"
#include "util/header.h"

#include "util/parse-options.h"

#include "perf.h"
#include "util/debug.h"

#include "util/trace-event.h"
#include <sys/types.h>

static char			const *input_name = "perf.data";
static int			input;
static unsigned long		page_size;
static unsigned long		mmap_window = 32;

static unsigned long		total_comm = 0;

static struct rb_root		threads;
static struct thread		*last_match;

static struct perf_header	*header;
static u64			sample_type;


/*
 * Scheduler benchmarks
 */
#include <sys/resource.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/time.h>
#include <sys/prctl.h>

#include <linux/unistd.h>

#include <semaphore.h>
#include <pthread.h>
#include <signal.h>
#include <values.h>
#include <string.h>
#include <unistd.h>
#include <stdlib.h>
#include <assert.h>
#include <fcntl.h>
#include <time.h>
#include <math.h>

#include <stdio.h>

#define PR_SET_NAME	15               /* Set process name */

#define BUG_ON(x)	assert(!(x))

#define DEBUG		0

typedef unsigned long long nsec_t;

#define printk(x...)		do { printf(x); fflush(stdout); } while (0)

nsec_t prev_printk;

#define __dprintk(x,y...) do {						 \
	nsec_t __now = get_nsecs(), __delta = __now - prev_printk;	 \
									 \
	prev_printk = __now;						 \
									 \
	printf("%.3f [%Ld] [%.3f]: " x, (double)__now/1e6, __now, (double)__delta/1e6, y);\
} while (0)

#if !DEBUG
# define dprintk(x...)	do { } while (0)
#else
# define dprintk(x...)	__dprintk(x)
#endif

#define __DP()		__dprintk("parent: line %d\n", __LINE__)
#define DP()		dprintk("parent: line %d\n", __LINE__)
#define D()		dprintk("task %ld: line %d\n", this_task->nr, __LINE__)


static nsec_t run_measurement_overhead;
static nsec_t sleep_measurement_overhead;

static nsec_t get_nsecs(void)
{
	struct timespec ts;

	clock_gettime(CLOCK_MONOTONIC, &ts);

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

static void burn_nsecs(nsec_t nsecs)
{
	nsec_t T0 = get_nsecs(), T1;

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

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

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

	nanosleep(&ts, NULL);
}

static void calibrate_run_measurement_overhead(void)
{
	nsec_t T0, T1, delta, min_delta = 1000000000ULL;
	int i;

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

	printk("run measurement overhead: %Ld nsecs\n", min_delta);
}

static void calibrate_sleep_measurement_overhead(void)
{
	nsec_t 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;
	sleep_measurement_overhead = min_delta;

	printk("sleep measurement overhead: %Ld nsecs\n", min_delta);
}

#define COMM_LEN	20
#define SYM_LEN		129

#define MAX_PID		65536

static unsigned long nr_tasks;

struct sched_event;

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

	unsigned long		nr_events;
	unsigned long		curr_event;
	struct sched_event	**events;

	pthread_t		thread;
	sem_t			sleep_sem;

	sem_t			ready_for_work;
	sem_t			work_done_sem;

	nsec_t			cpu_usage;
};

enum sched_event_type {
	SCHED_EVENT_RUN,
	SCHED_EVENT_SLEEP,
	SCHED_EVENT_WAKEUP,
};

struct sched_event {
	enum sched_event_type	type;
	nsec_t			timestamp;
	nsec_t			duration;
	unsigned long		nr;
	int			specific_wait;
	sem_t			*wait_sem;
	struct task_desc	*wakee;
};

static struct task_desc		*pid_to_task[MAX_PID];

static struct task_desc		**tasks;

static pthread_mutex_t		start_work_mutex = PTHREAD_MUTEX_INITIALIZER;
static nsec_t			start_time;

static pthread_mutex_t		work_done_wait_mutex = PTHREAD_MUTEX_INITIALIZER;

static unsigned long		nr_run_events;
static unsigned long		nr_sleep_events;
static unsigned long		nr_wakeup_events;

static unsigned long		nr_sleep_corrections;
static unsigned long		nr_run_events_optimized;

static struct sched_event *
get_new_event(struct task_desc *task, nsec_t timestamp)
{
	struct sched_event *event = calloc(1, sizeof(*event));
	unsigned long idx = task->nr_events;
	size_t size;

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

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

	task->events[idx] = event;

	return event;
}

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

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

static void
add_sched_event_run(struct task_desc *task, nsec_t timestamp, u64 duration)
{
	struct sched_event *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) {
		nr_run_events_optimized++;
		curr_event->duration += duration;
		return;
	}

	event = get_new_event(task, timestamp);

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

	nr_run_events++;
}

static unsigned long targetless_wakeups;
static unsigned long multitarget_wakeups;

static void
add_sched_event_wakeup(struct task_desc *task, nsec_t timestamp,
		       struct task_desc *wakee)
{
	struct sched_event *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) {
		targetless_wakeups++;
		return;
	}
	if (wakee_event->wait_sem) {
		multitarget_wakeups++;
		return;
	}

	wakee_event->wait_sem = calloc(1, 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;

	nr_wakeup_events++;
}

static void
add_sched_event_sleep(struct task_desc *task, nsec_t timestamp,
		      unsigned long uninterruptible __used)
{
	struct sched_event *event = get_new_event(task, timestamp);

	event->type = SCHED_EVENT_SLEEP;

	nr_sleep_events++;
}

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

	BUG_ON(pid >= MAX_PID);

	task = pid_to_task[pid];

	if (task)
		return task;

	task = calloc(1, sizeof(*task));
	task->pid = pid;
	task->nr = 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(task, 0, 0);

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

	printk("registered task #%ld, PID %ld (%s)\n", nr_tasks, pid, comm);

	return task;
}


static int first_trace_line = 1;

static nsec_t first_timestamp;
static nsec_t prev_timestamp;

void parse_line(char *line);

void parse_line(char *line)
{
	unsigned long param1 = 0, param2 = 0;
	char comm[COMM_LEN], comm2[COMM_LEN];
	unsigned long pid, pid2, timestamp0;
	struct task_desc *task, *task2;
	char func_str[SYM_LEN];
	nsec_t timestamp;
	int ret;

	//"   <idle> 0     0D.s3    0us+: try_to_wake_up <events/0 9> (1 0)"
	ret = sscanf(line, "%20s %5ld %*s %ldus%*c:"
			   " %128s <%20s %ld> (%ld %ld)\n",
		comm, &pid, &timestamp0,
		func_str, comm2, &pid2, &param1, &param2);
	dprintk("ret: %d\n", ret);
	if (ret != 8)
		return;

	timestamp = timestamp0 * 1000LL;

	if (first_trace_line) {
		first_trace_line = 0;
		first_timestamp = timestamp;
	}

	timestamp -= first_timestamp;
	BUG_ON(timestamp < prev_timestamp);
	prev_timestamp = timestamp;

	dprintk("parsed: %s - %ld %Ld: %s - <%s %ld> (%ld %ld)\n",
		comm,
		pid,
		timestamp,
		func_str,
		comm2,
		pid2,
		param1,
		param2);

	task = register_pid(pid, comm);
	task2 = register_pid(pid2, comm2);

	if (!strcmp(func_str, "update_curr")) {
		dprintk("%Ld: task %ld runs for %ld nsecs\n",
			timestamp, task->nr, param1);
		add_sched_event_run(task, timestamp, param1);
	} else if (!strcmp(func_str, "try_to_wake_up")) {
		dprintk("%Ld: task %ld wakes up task %ld\n",
			timestamp, task->nr, task2->nr);
		add_sched_event_wakeup(task, timestamp, task2);
	} else if (!strcmp(func_str, "deactivate_task")) {
		dprintk("%Ld: task %ld goes to sleep (uninterruptible: %ld)\n",
			timestamp, task->nr, param1);
		add_sched_event_sleep(task, timestamp, param1);
	}
}

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

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

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

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

static void
process_sched_event(struct task_desc *this_task __used, struct sched_event *event)
{
	int ret = 0;
	nsec_t now;
	long long delta;

	now = get_nsecs();
	delta = start_time + event->timestamp - now;

	dprintk("task %ld, event #%ld, %Ld, delta: %.3f (%Ld)\n",
		this_task->nr, event->nr, event->timestamp,
		(double)delta/1e6, delta);

	if (0 && delta > 0) {
		dprintk("%.3f: task %ld FIX %.3f\n",
			(double)event->timestamp/1e6,
			this_task->nr,
			(double)delta/1e6);
		sleep_nsecs(start_time + event->timestamp - now);
		nr_sleep_corrections++;
	}

	switch (event->type) {
		case SCHED_EVENT_RUN:
			dprintk("%.3f: task %ld RUN for %.3f\n",
				(double)event->timestamp/1e6,
				this_task->nr,
				(double)event->duration/1e6);
			burn_nsecs(event->duration);
			break;
		case SCHED_EVENT_SLEEP:
			dprintk("%.3f: task %ld %s SLEEP\n",
				(double)event->timestamp/1e6,
				this_task->nr, event->wait_sem ? "" : "SKIP");
			if (event->wait_sem)
				ret = sem_wait(event->wait_sem);
			BUG_ON(ret);
			break;
		case SCHED_EVENT_WAKEUP:
			dprintk("%.3f: task %ld WAKEUP => task %ld\n",
				(double)event->timestamp/1e6,
				this_task->nr,
				event->wakee->nr);
			if (event->wait_sem)
				ret = sem_post(event->wait_sem);
			BUG_ON(ret);
			break;
		default:
			BUG_ON(1);
	}
}

static nsec_t get_cpu_usage_nsec_parent(void)
{
	struct rusage ru;
	nsec_t 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 nsec_t get_cpu_usage_nsec_self(void)
{
	char filename [] = "/proc/1234567890/sched";
	unsigned long msecs, nsecs;
	char *line = NULL;
	nsec_t total = 0;
	size_t len = 0;
	ssize_t chars;
	FILE *file;
	int ret;

	sprintf(filename, "/proc/%d/sched", getpid());
	file = fopen(filename, "r");
	BUG_ON(!file);

	while ((chars = getline(&line, &len, file)) != -1) {
		dprintk("got line with length %zu :\n", chars);
		dprintk("%s", line);
		ret = sscanf(line, "se.sum_exec_runtime : %ld.%06ld\n",
			&msecs, &nsecs);
		if (ret == 2) {
			total = msecs*1e6 + nsecs;
			dprintk("total: (%ld.%06ld) %Ld\n",
				msecs, nsecs, total);
			break;
		}
	}
	if (line)
		free(line);
	fclose(file);

	return total;
}

static void *thread_func(void *ctx)
{
	struct task_desc *this_task = ctx;
	nsec_t cpu_usage_0, cpu_usage_1;
	unsigned long i, ret;
	char comm2[22];

	dprintk("task %ld started up.\n", this_task->nr);
	sprintf(comm2, ":%s", this_task->comm);
	prctl(PR_SET_NAME, comm2);

again:
	ret = sem_post(&this_task->ready_for_work);
	BUG_ON(ret);
	D();
	ret = pthread_mutex_lock(&start_work_mutex);
	BUG_ON(ret);
	ret = pthread_mutex_unlock(&start_work_mutex);
	BUG_ON(ret);
	D();

	cpu_usage_0 = get_cpu_usage_nsec_self();

	for (i = 0; i < this_task->nr_events; i++) {
		this_task->curr_event = i;
		process_sched_event(this_task, this_task->events[i]);
	}

	cpu_usage_1 = get_cpu_usage_nsec_self();
	this_task->cpu_usage = cpu_usage_1 - cpu_usage_0;

	dprintk("task %ld cpu usage: %0.3f msecs\n",
		this_task->nr, (double)this_task->cpu_usage / 1e6);

	D();
	ret = sem_post(&this_task->work_done_sem);
	BUG_ON(ret);
	D();

	ret = pthread_mutex_lock(&work_done_wait_mutex);
	BUG_ON(ret);
	ret = pthread_mutex_unlock(&work_done_wait_mutex);
	BUG_ON(ret);
	D();

	goto again;
}

static void create_tasks(void)
{
	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)(16*1024));
	BUG_ON(err);
	err = pthread_mutex_lock(&start_work_mutex);
	BUG_ON(err);
	err = pthread_mutex_lock(&work_done_wait_mutex);
	BUG_ON(err);
	for (i = 0; i < nr_tasks; i++) {
		task = tasks[i];
		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, task);
		BUG_ON(err);
	}
}

static nsec_t cpu_usage;
static nsec_t runavg_cpu_usage;
static nsec_t parent_cpu_usage;
static nsec_t runavg_parent_cpu_usage;

static void wait_for_tasks(void)
{
	nsec_t cpu_usage_0, cpu_usage_1;
	struct task_desc *task;
	unsigned long i, ret;

	DP();
	start_time = get_nsecs();
	DP();
	cpu_usage = 0;
	pthread_mutex_unlock(&work_done_wait_mutex);

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

	cpu_usage_0 = get_cpu_usage_nsec_parent();

	pthread_mutex_unlock(&start_work_mutex);

#if 0
	for (i = 0; i < nr_tasks; i++) {
		unsigned long missed;

		task = tasks[i];
		while (task->curr_event + 1 < task->nr_events) {
			dprintk("parent waiting for %ld (%ld != %ld)\n",
				i, task->curr_event, task->nr_events);
			sleep_nsecs(100000000);
		}
		missed = task->nr_events - 1 - task->curr_event;
		if (missed)
			printk("task %ld missed events: %ld\n", i, missed);
		ret = sem_post(&task->sleep_sem);
		BUG_ON(ret);
	}
#endif
	DP();
	for (i = 0; i < nr_tasks; i++) {
		task = tasks[i];
		ret = sem_wait(&task->work_done_sem);
		BUG_ON(ret);
		sem_init(&task->work_done_sem, 0, 0);
		cpu_usage += task->cpu_usage;
		task->cpu_usage = 0;
	}

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

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

	ret = pthread_mutex_lock(&start_work_mutex);
	BUG_ON(ret);

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

static int __cmd_sched(void);

static void parse_trace(void)
{
	__cmd_sched();

	printk("nr_run_events:        %ld\n", nr_run_events);
	printk("nr_sleep_events:      %ld\n", nr_sleep_events);
	printk("nr_wakeup_events:     %ld\n", nr_wakeup_events);

	if (targetless_wakeups)
		printk("target-less wakeups:  %ld\n", targetless_wakeups);
	if (multitarget_wakeups)
		printk("multi-target wakeups: %ld\n", multitarget_wakeups);
	if (nr_run_events_optimized)
		printk("run events optimized: %ld\n",
			nr_run_events_optimized);
}

static unsigned long nr_runs;
static nsec_t sum_runtime;
static nsec_t sum_fluct;
static nsec_t run_avg;

static void run_one_test(void)
{
	nsec_t T0, T1, delta, avg_delta, fluct, std_dev;

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

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

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

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

#if 0
	printk("%0.2f +- %0.2f, ",
		(double)avg_delta/1e6, (double)std_dev/1e6);
#endif
	printk("ravg: %0.2f, ",
		(double)run_avg/1e6);

	printk("cpu: %0.2f / %0.2f",
		(double)cpu_usage/1e6, (double)runavg_cpu_usage/1e6);

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

	printk("\n");

	if (nr_sleep_corrections)
		printk(" (%ld sleep corrections)\n", nr_sleep_corrections);
	nr_sleep_corrections = 0;
}

static void test_calibrations(void)
{
	nsec_t T0, T1;

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

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

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

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

static int
process_comm_event(event_t *event, unsigned long offset, unsigned long head)
{
	struct thread *thread;

	thread = threads__findnew(event->comm.pid, &threads, &last_match);

	dump_printf("%p [%p]: PERF_EVENT_COMM: %s:%d\n",
		(void *)(offset + head),
		(void *)(long)(event->header.size),
		event->comm.comm, event->comm.pid);

	if (thread == NULL ||
	    thread__set_comm(thread, event->comm.comm)) {
		dump_printf("problem processing PERF_EVENT_COMM, skipping event.\n");
		return -1;
	}
	total_comm++;

	return 0;
}

struct trace_wakeup_event {
	u32 size;

	u16 common_type;
	u8 common_flags;
	u8 common_preempt_count;
	u32 common_pid;
	u32 common_tgid;

	char comm[16];
	u32 pid;

	u32 prio;
	u32 success;
	u32 cpu;
};

static void
process_sched_wakeup_event(struct trace_wakeup_event *wakeup_event, struct event *event,
		  int cpu __used, u64 timestamp __used, struct thread *thread __used)
{
	struct task_desc *waker, *wakee;

	printf("sched_wakeup event %p\n", event);

	printf(" ... pid %d woke up %s/%d\n",
		wakeup_event->common_pid,
		wakeup_event->comm,
		wakeup_event->pid);

	waker = register_pid(wakeup_event->common_pid, "<unknown>");
	wakee = register_pid(wakeup_event->pid, wakeup_event->comm);

	add_sched_event_wakeup(waker, timestamp, wakee);
}

struct trace_switch_event {
	u32 size;

	u16 common_type;
	u8 common_flags;
	u8 common_preempt_count;
	u32 common_pid;
	u32 common_tgid;

	char prev_comm[16];
	u32 prev_pid;
	u32 prev_prio;
	u64 prev_state;
	char next_comm[16];
	u32 next_pid;
	u32 next_prio;
};

#define MAX_CPUS 4096

unsigned long cpu_last_switched[MAX_CPUS];

static void
process_sched_switch_event(struct trace_switch_event *switch_event, struct event *event,
		  int cpu __used, u64 timestamp __used, struct thread *thread __used)
{
	struct task_desc *prev, *next;
	u64 timestamp0;
	s64 delta;

	printf("sched_switch event %p\n", event);
	if (cpu >= MAX_CPUS || cpu < 0)
		return;

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

	if (delta < 0)
		die("hm, delta: %Ld < 0 ?\n", delta);

	printf(" ... switch from %s/%d to %s/%d [ran %Ld nsecs]\n",
		switch_event->prev_comm, switch_event->prev_pid,
		switch_event->next_comm, switch_event->next_pid,
		delta);

	prev = register_pid(switch_event->prev_pid, switch_event->prev_comm);
	next = register_pid(switch_event->next_pid, switch_event->next_comm);

	cpu_last_switched[cpu] = timestamp;

	add_sched_event_run(prev, timestamp, delta);
}

struct trace_fork_event {
	u32 size;

	u16 common_type;
	u8 common_flags;
	u8 common_preempt_count;
	u32 common_pid;
	u32 common_tgid;

	char parent_comm[16];
	u32 parent_pid;
	char child_comm[16];
	u32 child_pid;
};

static void
process_sched_fork_event(struct trace_fork_event *fork_event, struct event *event,
		  int cpu __used, u64 timestamp __used, struct thread *thread __used)
{
	printf("sched_fork event %p\n", event);
	printf("... parent: %s/%d\n", fork_event->parent_comm, fork_event->parent_pid);
	printf("...  child: %s/%d\n", fork_event->child_comm, fork_event->child_pid);
	register_pid(fork_event->parent_pid, fork_event->parent_comm);
	register_pid(fork_event->child_pid, fork_event->child_comm);
}

static void process_sched_exit_event(struct event *event,
		  int cpu __used, u64 timestamp __used, struct thread *thread __used)
{
	printf("sched_exit event %p\n", event);
}

static void
process_raw_event(event_t *raw_event, void *more_data,
		  int cpu, u64 timestamp, struct thread *thread)
{
	struct {
		u32 size;
		char data[0];
	} *raw = more_data;
	struct event *event;
	int type;

	type = trace_parse_common_type(raw->data);
	event = trace_find_event(type);

	/*
	 * FIXME: better resolve from pid from the struct trace_entry
	 * field, although it should be the same than this perf
	 * event pid
	 */
	printf("id %d, type: %d, event: %s\n",
		raw_event->header.type, type, event->name);

	if (!strcmp(event->name, "sched_switch"))
		process_sched_switch_event(more_data, event, cpu, timestamp, thread);
	if (!strcmp(event->name, "sched_wakeup"))
		process_sched_wakeup_event(more_data, event, cpu, timestamp, thread);
	if (!strcmp(event->name, "sched_wakeup_new"))
		process_sched_wakeup_event(more_data, event, cpu, timestamp, thread);
	if (!strcmp(event->name, "sched_process_fork"))
		process_sched_fork_event(more_data, event, cpu, timestamp, thread);
	if (!strcmp(event->name, "sched_process_exit"))
		process_sched_exit_event(event, cpu, timestamp, thread);
}

static int
process_sample_event(event_t *event, unsigned long offset, unsigned long head)
{
	char level;
	int show = 0;
	struct dso *dso = NULL;
	struct thread *thread;
	u64 ip = event->ip.ip;
	u64 timestamp = -1;
	u32 cpu = -1;
	u64 period = 1;
	void *more_data = event->ip.__more_data;
	int cpumode;

	thread = threads__findnew(event->ip.pid, &threads, &last_match);

	if (sample_type & PERF_SAMPLE_TIME) {
		timestamp = *(u64 *)more_data;
		more_data += sizeof(u64);
	}

	if (sample_type & PERF_SAMPLE_CPU) {
		cpu = *(u32 *)more_data;
		more_data += sizeof(u32);
		more_data += sizeof(u32); /* reserved */
	}

	if (sample_type & PERF_SAMPLE_PERIOD) {
		period = *(u64 *)more_data;
		more_data += sizeof(u64);
	}

	dump_printf("%p [%p]: PERF_EVENT_SAMPLE (IP, %d): %d/%d: %p period: %Ld\n",
		(void *)(offset + head),
		(void *)(long)(event->header.size),
		event->header.misc,
		event->ip.pid, event->ip.tid,
		(void *)(long)ip,
		(long long)period);

	dump_printf(" ... thread: %s:%d\n", thread->comm, thread->pid);

	if (thread == NULL) {
		eprintf("problem processing %d event, skipping it.\n",
			event->header.type);
		return -1;
	}

	cpumode = event->header.misc & PERF_EVENT_MISC_CPUMODE_MASK;

	if (cpumode == PERF_EVENT_MISC_KERNEL) {
		show = SHOW_KERNEL;
		level = 'k';

		dso = kernel_dso;

		dump_printf(" ...... dso: %s\n", dso->name);

	} else if (cpumode == PERF_EVENT_MISC_USER) {

		show = SHOW_USER;
		level = '.';

	} else {
		show = SHOW_HV;
		level = 'H';

		dso = hypervisor_dso;

		dump_printf(" ...... dso: [hypervisor]\n");
	}

	if (sample_type & PERF_SAMPLE_RAW)
		process_raw_event(event, more_data, cpu, timestamp, thread);

	return 0;
}

static int
process_event(event_t *event, unsigned long offset, unsigned long head)
{
	trace_event(event);

	switch (event->header.type) {
	case PERF_EVENT_MMAP ... PERF_EVENT_LOST:
		return 0;

	case PERF_EVENT_COMM:
		return process_comm_event(event, offset, head);

	case PERF_EVENT_EXIT ... PERF_EVENT_READ:
		return 0;

	case PERF_EVENT_SAMPLE:
		return process_sample_event(event, offset, head);

	case PERF_EVENT_MAX:
	default:
		return -1;
	}

	return 0;
}

static int __cmd_sched(void)
{
	int ret, rc = EXIT_FAILURE;
	unsigned long offset = 0;
	unsigned long head = 0;
	struct stat perf_stat;
	event_t *event;
	uint32_t size;
	char *buf;

	trace_report();
	register_idle_thread(&threads, &last_match);

	input = open(input_name, O_RDONLY);
	if (input < 0) {
		perror("failed to open file");
		exit(-1);
	}

	ret = fstat(input, &perf_stat);
	if (ret < 0) {
		perror("failed to stat file");
		exit(-1);
	}

	if (!perf_stat.st_size) {
		fprintf(stderr, "zero-sized file, nothing to do!\n");
		exit(0);
	}
	header = perf_header__read(input);
	head = header->data_offset;
	sample_type = perf_header__sample_type(header);

	if (!(sample_type & PERF_SAMPLE_RAW))
		die("No trace sample to read. Did you call perf record "
		    "without -R?");

	if (load_kernel() < 0) {
		perror("failed to load kernel symbols");
		return EXIT_FAILURE;
	}

remap:
	buf = (char *)mmap(NULL, page_size * mmap_window, PROT_READ,
			   MAP_SHARED, input, offset);
	if (buf == MAP_FAILED) {
		perror("failed to mmap file");
		exit(-1);
	}

more:
	event = (event_t *)(buf + head);

	size = event->header.size;
	if (!size)
		size = 8;

	if (head + event->header.size >= page_size * mmap_window) {
		unsigned long shift = page_size * (head / page_size);
		int res;

		res = munmap(buf, page_size * mmap_window);
		assert(res == 0);

		offset += shift;
		head -= shift;
		goto remap;
	}

	size = event->header.size;


	if (!size || process_event(event, offset, head) < 0) {

		/*
		 * assume we lost track of the stream, check alignment, and
		 * increment a single u64 in the hope to catch on again 'soon'.
		 */

		if (unlikely(head & 7))
			head &= ~7ULL;

		size = 8;
	}

	head += size;

	if (offset + head < (unsigned long)perf_stat.st_size)
		goto more;

	rc = EXIT_SUCCESS;
	close(input);

	return rc;
}

static const char * const annotate_usage[] = {
	"perf trace [<options>] <command>",
	NULL
};

static const struct option options[] = {
	OPT_BOOLEAN('D', "dump-raw-trace", &dump_trace,
		    "dump raw trace in ASCII"),
	OPT_BOOLEAN('v', "verbose", &verbose,
		    "be more verbose (show symbol address, etc)"),
	OPT_END()
};

int cmd_sched(int argc, const char **argv, const char *prefix __used)
{
	long nr_iterations = 10, i;

	symbol__init();
	page_size = getpagesize();

	argc = parse_options(argc, argv, options, annotate_usage, 0);
	if (argc) {
		/*
		 * Special case: if there's an argument left then assume tha
		 * it's a symbol filter:
		 */
		if (argc > 1)
			usage_with_options(annotate_usage, options);
	}

//	setup_pager();

	calibrate_run_measurement_overhead();
	calibrate_sleep_measurement_overhead();

	test_calibrations();

	parse_trace();
	print_task_traces();
	add_cross_task_wakeups();

	create_tasks();
	printk("------------------------------------------------------------\n");
	for (i = 0; i < nr_iterations; i++)
		run_one_test();

	return 0;
}