perf: Add the timechart tool

timechart is a tool to visualize what is going on in the system.

The user makes a trace of what is going on with

 > perf record --timechart /usr/bin/some_command

and then can turn the output of this into an svg file

 > perf timechart

which then can be viewed with any SVG view; inkscape works well
enough for me.

The idea behind timechart is to create a "infinitely zoomable"
picture; something that has high level information on a 1:1 zoom
level, but which exposes more details every time you zoom into a
specific area.

Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Acked-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Paul Mackerras <paulus@samba.org>
Cc: Frederic Weisbecker <fweisbec@gmail.com>
LKML-Reference: <20090912130713.6a77bbc0@infradead.org>
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 1120 insertions, 0 deletions

diff --git a/tools/perf/builtin-timechart.c b/tools/perf/builtin-timechart.c
new file mode 100644
index 00000000000..00fac1b362f
--- /dev/null
+++ b/tools/perf/builtin-timechart.c
@@ -0,0 +1,1120 @@
+/*
+ * 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 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;
+
+		/* 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;
+						if (p->pid == we->wakee)
+							to = c->Y;
+					}
+					c = c->next;
+				}
+			}
+			p = p->next;
+		}
+
+		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, to);
+		we = we->next;
+	}
+}
+
+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, p->start_time, p->end_time, "process");
+			sample = c->samples;
+			while (sample) {
+				if (sample->type == TYPE_RUNNING)
+					svg_sample(Y, sample->cpu, sample->start_time, sample->end_time, "sample");
+				if (sample->type == TYPE_BLOCKED)
+					svg_box(Y, sample->start_time, sample->end_time, "blocked");
+				if (sample->type == TYPE_WAITING)
+					svg_box(Y, sample->start_time, sample->end_time, "waiting");
+				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)
+			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) {
+				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);
+
+	svg_time_grid(first_time, last_time);
+	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_EVENT_COMM:
+		return process_comm_event(event);
+	case PERF_EVENT_FORK:
+		return process_fork_event(event);
+	case PERF_EVENT_EXIT:
+		return process_exit_event(event);
+	case PERF_EVENT_SAMPLE:
+		return queue_sample_event(event);
+
+	/*
+	 * We dont process them right now but they are fine:
+	 */
+	case PERF_EVENT_MMAP:
+	case PERF_EVENT_THROTTLE:
+	case PERF_EVENT_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 report_usage[] = {
+	"perf report [<options>] <command>",
+	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_END()
+};
+
+
+int cmd_timechart(int argc, const char **argv, const char *prefix __used)
+{
+	symbol__init();
+
+	page_size = getpagesize();
+
+	argc = parse_options(argc, argv, options, report_usage, 0);
+
+	/*
+	 * Any (unrecognized) arguments left?
+	 */
+	if (argc)
+		usage_with_options(report_usage, options);
+
+	setup_pager();
+
+	return __cmd_timechart();
+}