/*
 * builtin-timechart.c - make an svg timechart of system activity
 *
 * (C) Copyright 2009 Intel Corporation
 *
 * Authors:
 *     Arjan van de Ven <arjan@linux.intel.com>
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; version 2
 * of the License.
 */

#include "builtin.h"

#include "util/util.h"

#include "util/color.h"
#include <linux/list.h>
#include "util/cache.h"
#include <linux/rbtree.h>
#include "util/symbol.h"
#include "util/string.h"
#include "util/callchain.h"
#include "util/strlist.h"

#include "perf.h"
#include "util/header.h"
#include "util/parse-options.h"
#include "util/parse-events.h"
#include "util/svghelper.h"

static char             const *input_name = "perf.data";
static char             const *output_name = "output.svg";


static unsigned long    page_size;
static unsigned long    mmap_window = 32;
static u64              sample_type;

static unsigned int     numcpus;
static u64              min_freq;       /* Lowest CPU frequency seen */
static u64              max_freq;       /* Highest CPU frequency seen */
static u64              turbo_frequency;

static u64              first_time, last_time;

static int              power_only;


static struct perf_header       *header;

struct per_pid;
struct per_pidcomm;

struct cpu_sample;
struct power_event;
struct wake_event;

struct sample_wrapper;

/*
 * Datastructure layout:
 * We keep an list of "pid"s, matching the kernels notion of a task struct.
 * Each "pid" entry, has a list of "comm"s.
 *      this is because we want to track different programs different, while
 *      exec will reuse the original pid (by design).
 * Each comm has a list of samples that will be used to draw
 * final graph.
 */

struct per_pid {
        struct per_pid *next;

        int             pid;
        int             ppid;

        u64             start_time;
        u64             end_time;
        u64             total_time;
        int             display;

        struct per_pidcomm *all;
        struct per_pidcomm *current;

        int painted;
};


struct per_pidcomm {
        struct per_pidcomm *next;

        u64             start_time;
        u64             end_time;
        u64             total_time;

        int             Y;
        int             display;

        long            state;
        u64             state_since;

        char            *comm;

        struct cpu_sample *samples;
};

struct sample_wrapper {
        struct sample_wrapper *next;

        u64             timestamp;
        unsigned char   data[0];
};

#define TYPE_NONE       0
#define TYPE_RUNNING    1
#define TYPE_WAITING    2
#define TYPE_BLOCKED    3

struct cpu_sample {
        struct cpu_sample *next;

        u64 start_time;
        u64 end_time;
        int type;
        int cpu;
};

static struct per_pid *all_data;

#define CSTATE 1
#define PSTATE 2

struct power_event {
        struct power_event *next;
        int type;
        int state;
        u64 start_time;
        u64 end_time;
        int cpu;
};

struct wake_event {
        struct wake_event *next;
        int waker;
        int wakee;
        u64 time;
};

static struct power_event    *power_events;
static struct wake_event     *wake_events;

struct sample_wrapper *all_samples;

static struct per_pid *find_create_pid(int pid)
{
        struct per_pid *cursor = all_data;

        while (cursor) {
                if (cursor->pid == pid)
                        return cursor;
                cursor = cursor->next;
        }
        cursor = malloc(sizeof(struct per_pid));
        assert(cursor != NULL);
        memset(cursor, 0, sizeof(struct per_pid));
        cursor->pid = pid;
        cursor->next = all_data;
        all_data = cursor;
        return cursor;
}

static void pid_set_comm(int pid, char *comm)
{
        struct per_pid *p;
        struct per_pidcomm *c;
        p = find_create_pid(pid);
        c = p->all;
        while (c) {
                if (c->comm && strcmp(c->comm, comm) == 0) {
                        p->current = c;
                        return;
                }
                if (!c->comm) {
                        c->comm = strdup(comm);
                        p->current = c;
                        return;
                }
                c = c->next;
        }
        c = malloc(sizeof(struct per_pidcomm));
        assert(c != NULL);
        memset(c, 0, sizeof(struct per_pidcomm));
        c->comm = strdup(comm);
        p->current = c;
        c->next = p->all;
        p->all = c;
}

static void pid_fork(int pid, int ppid, u64 timestamp)
{
        struct per_pid *p, *pp;
        p = find_create_pid(pid);
        pp = find_create_pid(ppid);
        p->ppid = ppid;
        if (pp->current && pp->current->comm && !p->current)
                pid_set_comm(pid, pp->current->comm);

        p->start_time = timestamp;
        if (p->current) {
                p->current->start_time = timestamp;
                p->current->state_since = timestamp;
        }
}

static void pid_exit(int pid, u64 timestamp)
{
        struct per_pid *p;
        p = find_create_pid(pid);
        p->end_time = timestamp;
        if (p->current)
                p->current->end_time = timestamp;
}

static void
pid_put_sample(int pid, int type, unsigned int cpu, u64 start, u64 end)
{
        struct per_pid *p;
        struct per_pidcomm *c;
        struct cpu_sample *sample;

        p = find_create_pid(pid);
        c = p->current;
        if (!c) {
                c = malloc(sizeof(struct per_pidcomm));
                assert(c != NULL);
                memset(c, 0, sizeof(struct per_pidcomm));
                p->current = c;
                c->next = p->all;
                p->all = c;
        }

        sample = malloc(sizeof(struct cpu_sample));
        assert(sample != NULL);
        memset(sample, 0, sizeof(struct cpu_sample));
        sample->start_time = start;
        sample->end_time = end;
        sample->type = type;
        sample->next = c->samples;
        sample->cpu = cpu;
        c->samples = sample;

        if (sample->type == TYPE_RUNNING && end > start && start > 0) {
                c->total_time += (end-start);
                p->total_time += (end-start);
        }

        if (c->start_time == 0 || c->start_time > start)
                c->start_time = start;
        if (p->start_time == 0 || p->start_time > start)
                p->start_time = start;

        if (cpu > numcpus)
                numcpus = cpu;
}

#define MAX_CPUS 4096

static u64 cpus_cstate_start_times[MAX_CPUS];
static int cpus_cstate_state[MAX_CPUS];
static u64 cpus_pstate_start_times[MAX_CPUS];
static u64 cpus_pstate_state[MAX_CPUS];

static int
process_comm_event(event_t *event)
{
        pid_set_comm(event->comm.pid, event->comm.comm);
        return 0;
}
static int
process_fork_event(event_t *event)
{
        pid_fork(event->fork.pid, event->fork.ppid, event->fork.time);
        return 0;
}

static int
process_exit_event(event_t *event)
{
        pid_exit(event->fork.pid, event->fork.time);
        return 0;
}

struct trace_entry {
        u32                     size;
        unsigned short          type;
        unsigned char           flags;
        unsigned char           preempt_count;
        int                     pid;
        int                     tgid;
};

struct power_entry {
        struct trace_entry te;
        s64     type;
        s64     value;
};

#define TASK_COMM_LEN 16
struct wakeup_entry {
        struct trace_entry te;
        char comm[TASK_COMM_LEN];
        int   pid;
        int   prio;
        int   success;
};

/*
 * trace_flag_type is an enumeration that holds different
 * states when a trace occurs. These are:
 *  IRQS_OFF            - interrupts were disabled
 *  IRQS_NOSUPPORT      - arch does not support irqs_disabled_flags
 *  NEED_RESCED         - reschedule is requested
 *  HARDIRQ             - inside an interrupt handler
 *  SOFTIRQ             - inside a softirq handler
 */
enum trace_flag_type {
        TRACE_FLAG_IRQS_OFF             = 0x01,
        TRACE_FLAG_IRQS_NOSUPPORT       = 0x02,
        TRACE_FLAG_NEED_RESCHED         = 0x04,
        TRACE_FLAG_HARDIRQ              = 0x08,
        TRACE_FLAG_SOFTIRQ              = 0x10,
};



struct sched_switch {
        struct trace_entry te;
        char prev_comm[TASK_COMM_LEN];
        int  prev_pid;
        int  prev_prio;
        long prev_state; /* Arjan weeps. */
        char next_comm[TASK_COMM_LEN];
        int  next_pid;
        int  next_prio;
};

static void c_state_start(int cpu, u64 timestamp, int state)
{
        cpus_cstate_start_times[cpu] = timestamp;
        cpus_cstate_state[cpu] = state;
}

static void c_state_end(int cpu, u64 timestamp)
{
        struct power_event *pwr;
        pwr = malloc(sizeof(struct power_event));
        if (!pwr)
                return;
        memset(pwr, 0, sizeof(struct power_event));

        pwr->state = cpus_cstate_state[cpu];
        pwr->start_time = cpus_cstate_start_times[cpu];
        pwr->end_time = timestamp;
        pwr->cpu = cpu;
        pwr->type = CSTATE;
        pwr->next = power_events;

        power_events = pwr;
}

static void p_state_change(int cpu, u64 timestamp, u64 new_freq)
{
        struct power_event *pwr;
        pwr = malloc(sizeof(struct power_event));

        if (new_freq > 8000000) /* detect invalid data */
                return;

        if (!pwr)
                return;
        memset(pwr, 0, sizeof(struct power_event));

        pwr->state = cpus_pstate_state[cpu];
        pwr->start_time = cpus_pstate_start_times[cpu];
        pwr->end_time = timestamp;
        pwr->cpu = cpu;
        pwr->type = PSTATE;
        pwr->next = power_events;

        if (!pwr->start_time)
                pwr->start_time = first_time;

        power_events = pwr;

        cpus_pstate_state[cpu] = new_freq;
        cpus_pstate_start_times[cpu] = timestamp;

        if ((u64)new_freq > max_freq)
                max_freq = new_freq;

        if (new_freq < min_freq || min_freq == 0)
                min_freq = new_freq;

        if (new_freq == max_freq - 1000)
                        turbo_frequency = max_freq;
}

static void
sched_wakeup(int cpu, u64 timestamp, int pid, struct trace_entry *te)
{
        struct wake_event *we;
        struct per_pid *p;
        struct wakeup_entry *wake = (void *)te;

        we = malloc(sizeof(struct wake_event));
        if (!we)
                return;

        memset(we, 0, sizeof(struct wake_event));
        we->time = timestamp;
        we->waker = pid;

        if ((te->flags & TRACE_FLAG_HARDIRQ) || (te->flags & TRACE_FLAG_SOFTIRQ))
                we->waker = -1;

        we->wakee = wake->pid;
        we->next = wake_events;
        wake_events = we;
        p = find_create_pid(we->wakee);

        if (p && p->current && p->current->state == TYPE_NONE) {
                p->current->state_since = timestamp;
                p->current->state = TYPE_WAITING;
        }
        if (p && p->current && p->current->state == TYPE_BLOCKED) {
                pid_put_sample(p->pid, p->current->state, cpu, p->current->state_since, timestamp);
                p->current->state_since = timestamp;
                p->current->state = TYPE_WAITING;
        }
}

static void sched_switch(int cpu, u64 timestamp, struct trace_entry *te)
{
        struct per_pid *p = NULL, *prev_p;
        struct sched_switch *sw = (void *)te;


        prev_p = find_create_pid(sw->prev_pid);

        p = find_create_pid(sw->next_pid);

        if (prev_p->current && prev_p->current->state != TYPE_NONE)
                pid_put_sample(sw->prev_pid, TYPE_RUNNING, cpu, prev_p->current->state_since, timestamp);
        if (p && p->current) {
                if (p->current->state != TYPE_NONE)
                        pid_put_sample(sw->next_pid, p->current->state, cpu, p->current->state_since, timestamp);

                        p->current->state_since = timestamp;
                        p->current->state = TYPE_RUNNING;
        }

        if (prev_p->current) {
                prev_p->current->state = TYPE_NONE;
                prev_p->current->state_since = timestamp;
                if (sw->prev_state & 2)
                        prev_p->current->state = TYPE_BLOCKED;
                if (sw->prev_state == 0)
                        prev_p->current->state = TYPE_WAITING;
        }
}


static int
process_sample_event(event_t *event)
{
        int cursor = 0;
        u64 addr = 0;
        u64 stamp = 0;
        u32 cpu = 0;
        u32 pid = 0;
        struct trace_entry *te;

        if (sample_type & PERF_SAMPLE_IP)
                cursor++;

        if (sample_type & PERF_SAMPLE_TID) {
                pid = event->sample.array[cursor]>>32;
                cursor++;
        }
        if (sample_type & PERF_SAMPLE_TIME) {
                stamp = event->sample.array[cursor++];

                if (!first_time || first_time > stamp)
                        first_time = stamp;
                if (last_time < stamp)
                        last_time = stamp;

        }
        if (sample_type & PERF_SAMPLE_ADDR)
                addr = event->sample.array[cursor++];
        if (sample_type & PERF_SAMPLE_ID)
                cursor++;
        if (sample_type & PERF_SAMPLE_STREAM_ID)
                cursor++;
        if (sample_type & PERF_SAMPLE_CPU)
                cpu = event->sample.array[cursor++] & 0xFFFFFFFF;
        if (sample_type & PERF_SAMPLE_PERIOD)
                cursor++;

        te = (void *)&event->sample.array[cursor];

        if (sample_type & PERF_SAMPLE_RAW && te->size > 0) {
                char *event_str;
                struct power_entry *pe;

                pe = (void *)te;

                event_str = perf_header__find_event(te->type);

                if (!event_str)
                        return 0;

                if (strcmp(event_str, "power:power_start") == 0)
                        c_state_start(cpu, stamp, pe->value);

                if (strcmp(event_str, "power:power_end") == 0)
                        c_state_end(cpu, stamp);

                if (strcmp(event_str, "power:power_frequency") == 0)
                        p_state_change(cpu, stamp, pe->value);

                if (strcmp(event_str, "sched:sched_wakeup") == 0)
                        sched_wakeup(cpu, stamp, pid, te);

                if (strcmp(event_str, "sched:sched_switch") == 0)
                        sched_switch(cpu, stamp, te);
        }
        return 0;
}

/*
 * After the last sample we need to wrap up the current C/P state
 * and close out each CPU for these.
 */
static void end_sample_processing(void)
{
        u64 cpu;
        struct power_event *pwr;

        for (cpu = 0; cpu <= numcpus; cpu++) {
                pwr = malloc(sizeof(struct power_event));
                if (!pwr)
                        return;
                memset(pwr, 0, sizeof(struct power_event));

                /* C state */
#if 0
                pwr->state = cpus_cstate_state[cpu];
                pwr->start_time = cpus_cstate_start_times[cpu];
                pwr->end_time = last_time;
                pwr->cpu = cpu;
                pwr->type = CSTATE;
                pwr->next = power_events;

                power_events = pwr;
#endif
                /* P state */

                pwr = malloc(sizeof(struct power_event));
                if (!pwr)
                        return;
                memset(pwr, 0, sizeof(struct power_event));

                pwr->state = cpus_pstate_state[cpu];
                pwr->start_time = cpus_pstate_start_times[cpu];
                pwr->end_time = last_time;
                pwr->cpu = cpu;
                pwr->type = PSTATE;
                pwr->next = power_events;

                if (!pwr->start_time)
                        pwr->start_time = first_time;
                if (!pwr->state)
                        pwr->state = min_freq;
                power_events = pwr;
        }
}

static u64 sample_time(event_t *event)
{
        int cursor;

        cursor = 0;
        if (sample_type & PERF_SAMPLE_IP)
                cursor++;
        if (sample_type & PERF_SAMPLE_TID)
                cursor++;
        if (sample_type & PERF_SAMPLE_TIME)
                return event->sample.array[cursor];
        return 0;
}


/*
 * We first queue all events, sorted backwards by insertion.
 * The order will get flipped later.
 */
static int
queue_sample_event(event_t *event)
{
        struct sample_wrapper *copy, *prev;
        int size;

        size = event->sample.header.size + sizeof(struct sample_wrapper) + 8;

        copy = malloc(size);
        if (!copy)
                return 1;

        memset(copy, 0, size);

        copy->next = NULL;
        copy->timestamp = sample_time(event);

        memcpy(&copy->data, event, event->sample.header.size);

        /* insert in the right place in the list */

        if (!all_samples) {
                /* first sample ever */
                all_samples = copy;
                return 0;
        }

        if (all_samples->timestamp < copy->timestamp) {
                /* insert at the head of the list */
                copy->next = all_samples;
                all_samples = copy;
                return 0;
        }

        prev = all_samples;
        while (prev->next) {
                if (prev->next->timestamp < copy->timestamp) {
                        copy->next = prev->next;
                        prev->next = copy;
                        return 0;
                }
                prev = prev->next;
        }
        /* insert at the end of the list */
        prev->next = copy;

        return 0;
}

static void sort_queued_samples(void)
{
        struct sample_wrapper *cursor, *next;

        cursor = all_samples;
        all_samples = NULL;

        while (cursor) {
                next = cursor->next;
                cursor->next = all_samples;
                all_samples = cursor;
                cursor = next;
        }
}

/*
 * Sort the pid datastructure
 */
static void sort_pids(void)
{
        struct per_pid *new_list, *p, *cursor, *prev;
        /* sort by ppid first, then by pid, lowest to highest */

        new_list = NULL;

        while (all_data) {
                p = all_data;
                all_data = p->next;
                p->next = NULL;

                if (new_list == NULL) {
                        new_list = p;
                        p->next = NULL;
                        continue;
                }
                prev = NULL;
                cursor = new_list;
                while (cursor) {
                        if (cursor->ppid > p->ppid ||
                                (cursor->ppid == p->ppid && cursor->pid > p->pid)) {
                                /* must insert before */
                                if (prev) {
                                        p->next = prev->next;
                                        prev->next = p;
                                        cursor = NULL;
                                        continue;
                                } else {
                                        p->next = new_list;
                                        new_list = p;
                                        cursor = NULL;
                                        continue;
                                }
                        }

                        prev = cursor;
                        cursor = cursor->next;
                        if (!cursor)
                                prev->next = p;
                }
        }
        all_data = new_list;
}


static void draw_c_p_states(void)
{
        struct power_event *pwr;
        pwr = power_events;

        /*
         * two pass drawing so that the P state bars are on top of the C state blocks
         */
        while (pwr) {
                if (pwr->type == CSTATE)
                        svg_cstate(pwr->cpu, pwr->start_time, pwr->end_time, pwr->state);
                pwr = pwr->next;
        }

        pwr = power_events;
        while (pwr) {
                if (pwr->type == PSTATE) {
                        if (!pwr->state)
                                pwr->state = min_freq;
                        svg_pstate(pwr->cpu, pwr->start_time, pwr->end_time, pwr->state);
                }
                pwr = pwr->next;
        }
}

static void draw_wakeups(void)
{
        struct wake_event *we;
        struct per_pid *p;
        struct per_pidcomm *c;

        we = wake_events;
        while (we) {
                int from = 0, to = 0;
                char *task_from = NULL, *task_to = NULL;

                /* locate the column of the waker and wakee */
                p = all_data;
                while (p) {
                        if (p->pid == we->waker || p->pid == we->wakee) {
                                c = p->all;
                                while (c) {
                                        if (c->Y && c->start_time <= we->time && c->end_time >= we->time) {
                                                if (p->pid == we->waker) {
                                                        from = c->Y;
                                                        task_from = strdup(c->comm);
                                                }
                                                if (p->pid == we->wakee) {
                                                        to = c->Y;
                                                        task_to = strdup(c->comm);
                                                }
                                        }
                                        c = c->next;
                                }
                                c = p->all;
                                while (c) {
                                        if (p->pid == we->waker && !from) {
                                                from = c->Y;
                                                task_from = strdup(c->comm);
                                        }
                                        if (p->pid == we->wakee && !to) {
                                                to = c->Y;
                                                task_to = strdup(c->comm);
                                        }
                                        c = c->next;
                                }
                        }
                        p = p->next;
                }

                if (!task_from) {
                        task_from = malloc(40);
                        sprintf(task_from, "[%i]", we->waker);
                }
                if (!task_to) {
                        task_to = malloc(40);
                        sprintf(task_to, "[%i]", we->wakee);
                }

                if (we->waker == -1)
                        svg_interrupt(we->time, to);
                else if (from && to && abs(from - to) == 1)
                        svg_wakeline(we->time, from, to);
                else
                        svg_partial_wakeline(we->time, from, task_from, to, task_to);
                we = we->next;

                free(task_from);
                free(task_to);
        }
}

static void draw_cpu_usage(void)
{
        struct per_pid *p;
        struct per_pidcomm *c;
        struct cpu_sample *sample;
        p = all_data;
        while (p) {
                c = p->all;
                while (c) {
                        sample = c->samples;
                        while (sample) {
                                if (sample->type == TYPE_RUNNING)
                                        svg_process(sample->cpu, sample->start_time, sample->end_time, "sample", c->comm);

                                sample = sample->next;
                        }
                        c = c->next;
                }
                p = p->next;
        }
}

static void draw_process_bars(void)
{
        struct per_pid *p;
        struct per_pidcomm *c;
        struct cpu_sample *sample;
        int Y = 0;

        Y = 2 * numcpus + 2;

        p = all_data;
        while (p) {
                c = p->all;
                while (c) {
                        if (!c->display) {
                                c->Y = 0;
                                c = c->next;
                                continue;
                        }

                        svg_box(Y, c->start_time, c->end_time, "process");
                        sample = c->samples;
                        while (sample) {
                                if (sample->type == TYPE_RUNNING)
                                        svg_sample(Y, sample->cpu, sample->start_time, sample->end_time);
                                if (sample->type == TYPE_BLOCKED)
                                        svg_box(Y, sample->start_time, sample->end_time, "blocked");
                                if (sample->type == TYPE_WAITING)
                                        svg_waiting(Y, sample->start_time, sample->end_time);
                                sample = sample->next;
                        }

                        if (c->comm) {
                                char comm[256];
                                if (c->total_time > 5000000000) /* 5 seconds */
                                        sprintf(comm, "%s:%i (%2.2fs)", c->comm, p->pid, c->total_time / 1000000000.0);
                                else
                                        sprintf(comm, "%s:%i (%3.1fms)", c->comm, p->pid, c->total_time / 1000000.0);

                                svg_text(Y, c->start_time, comm);
                        }
                        c->Y = Y;
                        Y++;
                        c = c->next;
                }
                p = p->next;
        }
}

static int determine_display_tasks(u64 threshold)
{
        struct per_pid *p;
        struct per_pidcomm *c;
        int count = 0;

        p = all_data;
        while (p) {
                p->display = 0;
                if (p->start_time == 1)
                        p->start_time = first_time;

                /* no exit marker, task kept running to the end */
                if (p->end_time == 0)
                        p->end_time = last_time;
                if (p->total_time >= threshold && !power_only)
                        p->display = 1;

                c = p->all;

                while (c) {
                        c->display = 0;

                        if (c->start_time == 1)
                                c->start_time = first_time;

                        if (c->total_time >= threshold && !power_only) {
                                c->display = 1;
                                count++;
                        }

                        if (c->end_time == 0)
                                c->end_time = last_time;

                        c = c->next;
                }
                p = p->next;
        }
        return count;
}



#define TIME_THRESH 10000000

static void write_svg_file(const char *filename)
{
        u64 i;
        int count;

        numcpus++;


        count = determine_display_tasks(TIME_THRESH);

        /* We'd like to show at least 15 tasks; be less picky if we have fewer */
        if (count < 15)
                count = determine_display_tasks(TIME_THRESH / 10);

        open_svg(filename, numcpus, count, first_time, last_time);

        svg_time_grid();
        svg_legenda();

        for (i = 0; i < numcpus; i++)
                svg_cpu_box(i, max_freq, turbo_frequency);

        draw_cpu_usage();
        draw_process_bars();
        draw_c_p_states();
        draw_wakeups();

        svg_close();
}

static int
process_event(event_t *event)
{

        switch (event->header.type) {

        case PERF_RECORD_COMM:
                return process_comm_event(event);
        case PERF_RECORD_FORK:
                return process_fork_event(event);
        case PERF_RECORD_EXIT:
                return process_exit_event(event);
        case PERF_RECORD_SAMPLE:
                return queue_sample_event(event);

        /*
         * We dont process them right now but they are fine:
         */
        case PERF_RECORD_MMAP:
        case PERF_RECORD_THROTTLE:
        case PERF_RECORD_UNTHROTTLE:
                return 0;

        default:
                return -1;
        }

        return 0;
}

static void process_samples(void)
{
        struct sample_wrapper *cursor;
        event_t *event;

        sort_queued_samples();

        cursor = all_samples;
        while (cursor) {
                event = (void *)&cursor->data;
                cursor = cursor->next;

                process_sample_event(event);
        }
}


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

        input = open(input_name, O_RDONLY);
        if (input < 0) {
                fprintf(stderr, " failed to open file: %s", input_name);
                if (!strcmp(input_name, "perf.data"))
                        fprintf(stderr, "  (try 'perf record' first)");
                fprintf(stderr, "\n");
                exit(-1);
        }

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

        if (!statbuf.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);

        shift = page_size * (head / page_size);
        offset += shift;
        head -= shift;

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) {
                int ret2;

                shift = page_size * (head / page_size);

                ret2 = munmap(buf, page_size * mmap_window);
                assert(ret2 == 0);

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

        size = event->header.size;

        if (!size || process_event(event) < 0) {

                printf("%p [%p]: skipping unknown header type: %d\n",
                        (void *)(offset + head),
                        (void *)(long)(event->header.size),
                        event->header.type);

                /*
                 * 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 >= header->data_offset + header->data_size)
                goto done;

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

done:
        rc = EXIT_SUCCESS;
        close(input);


        process_samples();

        end_sample_processing();

        sort_pids();

        write_svg_file(output_name);

        printf("Written %2.1f seconds of trace to %s.\n", (last_time - first_time) / 1000000000.0, output_name);

        return rc;
}

static const char * const timechart_usage[] = {
        "perf timechart [<options>] {record}",
        NULL
};

static const char *record_args[] = {
        "record",
        "-a",
        "-R",
        "-M",
        "-f",
        "-c", "1",
        "-e", "power:power_start",
        "-e", "power:power_end",
        "-e", "power:power_frequency",
        "-e", "sched:sched_wakeup",
        "-e", "sched:sched_switch",
};

static int __cmd_record(int argc, const char **argv)
{
        unsigned int rec_argc, i, j;
        const char **rec_argv;

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

        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];

        return cmd_record(i, rec_argv, NULL);
}

static const struct option options[] = {
        OPT_STRING('i', "input", &input_name, "file",
                    "input file name"),
        OPT_STRING('o', "output", &output_name, "file",
                    "output file name"),
        OPT_INTEGER('w', "width", &svg_page_width,
                    "page width"),
        OPT_BOOLEAN('p', "power-only", &power_only,
                    "output power data only"),
        OPT_END()
};


int cmd_timechart(int argc, const char **argv, const char *prefix __used)
{
        symbol__init();

        page_size = getpagesize();

        argc = parse_options(argc, argv, options, timechart_usage,
                        PARSE_OPT_STOP_AT_NON_OPTION);

        if (argc && !strncmp(argv[0], "rec", 3))
                return __cmd_record(argc, argv);
        else if (argc)
                usage_with_options(timechart_usage, options);

        setup_pager();

        return __cmd_timechart();
}