[mirror_ubuntu-artful-kernel.git] / kernel / trace / trace_functions_graph.c

/*
 *
 * Function graph tracer.
 * Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com>
 * Mostly borrowed from function tracer which
 * is Copyright (c) Steven Rostedt <srostedt@redhat.com>
 *
 */
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/ftrace.h>
#include <linux/fs.h>

#include "trace.h"

#define TRACE_GRAPH_INDENT	2

/* Flag options */
#define TRACE_GRAPH_PRINT_OVERRUN	0x1
#define TRACE_GRAPH_PRINT_CPU		0x2
#define TRACE_GRAPH_PRINT_OVERHEAD	0x4
#define TRACE_GRAPH_PRINT_PROC		0x8

static struct tracer_opt trace_opts[] = {
	/* Display overruns ? */
	{ TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
	/* Display CPU ? */
	{ TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
	/* Display Overhead ? */
	{ TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
	/* Display proc name/pid */
	{ TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
	{ } /* Empty entry */
};

static struct tracer_flags tracer_flags = {
	/* Don't display overruns and proc by default */
	.val = TRACE_GRAPH_PRINT_CPU | TRACE_GRAPH_PRINT_OVERHEAD,
	.opts = trace_opts
};

/* pid on the last trace processed */
static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };

static int graph_trace_init(struct trace_array *tr)
{
	int cpu, ret;

	for_each_online_cpu(cpu)
		tracing_reset(tr, cpu);

	ret = register_ftrace_graph(&trace_graph_return,
					&trace_graph_entry);
	if (ret)
		return ret;
	tracing_start_cmdline_record();

	return 0;
}

static void graph_trace_reset(struct trace_array *tr)
{
	tracing_stop_cmdline_record();
	unregister_ftrace_graph();
}

static inline int log10_cpu(int nb)
{
	if (nb / 100)
		return 3;
	if (nb / 10)
		return 2;
	return 1;
}

static enum print_line_t
print_graph_cpu(struct trace_seq *s, int cpu)
{
	int i;
	int ret;
	int log10_this = log10_cpu(cpu);
	int log10_all = log10_cpu(cpus_weight_nr(cpu_online_map));


	/*
	 * Start with a space character - to make it stand out
	 * to the right a bit when trace output is pasted into
	 * email:
	 */
	ret = trace_seq_printf(s, " ");

	/*
	 * Tricky - we space the CPU field according to the max
	 * number of online CPUs. On a 2-cpu system it would take
	 * a maximum of 1 digit - on a 128 cpu system it would
	 * take up to 3 digits:
	 */
	for (i = 0; i < log10_all - log10_this; i++) {
		ret = trace_seq_printf(s, " ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}
	ret = trace_seq_printf(s, "%d) ", cpu);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

#define TRACE_GRAPH_PROCINFO_LENGTH	14

static enum print_line_t
print_graph_proc(struct trace_seq *s, pid_t pid)
{
	int i;
	int ret;
	int len;
	char comm[8];
	int spaces = 0;
	/* sign + log10(MAX_INT) + '\0' */
	char pid_str[11];

	strncpy(comm, trace_find_cmdline(pid), 7);
	comm[7] = '\0';
	sprintf(pid_str, "%d", pid);

	/* 1 stands for the "-" character */
	len = strlen(comm) + strlen(pid_str) + 1;

	if (len < TRACE_GRAPH_PROCINFO_LENGTH)
		spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;

	/* First spaces to align center */
	for (i = 0; i < spaces / 2; i++) {
		ret = trace_seq_printf(s, " ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Last spaces to align center */
	for (i = 0; i < spaces - (spaces / 2); i++) {
		ret = trace_seq_printf(s, " ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}
	return TRACE_TYPE_HANDLED;
}


/* If the pid changed since the last trace, output this event */
static enum print_line_t
verif_pid(struct trace_seq *s, pid_t pid, int cpu)
{
	pid_t prev_pid;
	int ret;

	if (last_pid[cpu] != -1 && last_pid[cpu] == pid)
		return TRACE_TYPE_HANDLED;

	prev_pid = last_pid[cpu];
	last_pid[cpu] = pid;

/*
 * Context-switch trace line:

 ------------------------------------------
 | 1)  migration/0--1  =>  sshd-1755
 ------------------------------------------

 */
	ret = trace_seq_printf(s,
		"\n ------------------------------------------\n |");
	if (!ret)
		TRACE_TYPE_PARTIAL_LINE;

	ret = print_graph_cpu(s, cpu);
	if (ret == TRACE_TYPE_PARTIAL_LINE)
		TRACE_TYPE_PARTIAL_LINE;

	ret = print_graph_proc(s, prev_pid);
	if (ret == TRACE_TYPE_PARTIAL_LINE)
		TRACE_TYPE_PARTIAL_LINE;

	ret = trace_seq_printf(s, " => ");
	if (!ret)
		TRACE_TYPE_PARTIAL_LINE;

	ret = print_graph_proc(s, pid);
	if (ret == TRACE_TYPE_PARTIAL_LINE)
		TRACE_TYPE_PARTIAL_LINE;

	ret = trace_seq_printf(s,
		"\n ------------------------------------------\n\n");
	if (!ret)
		TRACE_TYPE_PARTIAL_LINE;

	return ret;
}

static bool
trace_branch_is_leaf(struct trace_iterator *iter,
		struct ftrace_graph_ent_entry *curr)
{
	struct ring_buffer_iter *ring_iter;
	struct ring_buffer_event *event;
	struct ftrace_graph_ret_entry *next;

	ring_iter = iter->buffer_iter[iter->cpu];

	if (!ring_iter)
		return false;

	event = ring_buffer_iter_peek(ring_iter, NULL);

	if (!event)
		return false;

	next = ring_buffer_event_data(event);

	if (next->ent.type != TRACE_GRAPH_RET)
		return false;

	if (curr->ent.pid != next->ent.pid ||
			curr->graph_ent.func != next->ret.func)
		return false;

	return true;
}


static inline int
print_graph_duration(unsigned long long duration, struct trace_seq *s)
{
	unsigned long nsecs_rem = do_div(duration, 1000);
	return trace_seq_printf(s, "%4llu.%3lu us |  ", duration, nsecs_rem);
}

/* Signal a overhead of time execution to the output */
static int
print_graph_overhead(unsigned long long duration, struct trace_seq *s)
{
	/* Duration exceeded 100 msecs */
	if (duration > 100000ULL)
		return trace_seq_printf(s, "! ");

	/* Duration exceeded 10 msecs */
	if (duration > 10000ULL)
		return trace_seq_printf(s, "+ ");

	return trace_seq_printf(s, "  ");
}

/* Case of a leaf function on its call entry */
static enum print_line_t
print_graph_entry_leaf(struct trace_iterator *iter,
		struct ftrace_graph_ent_entry *entry, struct trace_seq *s)
{
	struct ftrace_graph_ret_entry *ret_entry;
	struct ftrace_graph_ret *graph_ret;
	struct ring_buffer_event *event;
	struct ftrace_graph_ent *call;
	unsigned long long duration;
	int ret;
	int i;

	event = ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
	ret_entry = ring_buffer_event_data(event);
	graph_ret = &ret_entry->ret;
	call = &entry->graph_ent;
	duration = graph_ret->rettime - graph_ret->calltime;

	/* Must not exceed 8 characters: 9999.999 us */
	if (duration > 10000000ULL)
		duration = 9999999ULL;

	/* Overhead */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
		ret = print_graph_overhead(duration, s);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* Duration */
	ret = print_graph_duration(duration, s);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Function */
	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
		ret = trace_seq_printf(s, " ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	ret = seq_print_ip_sym(s, call->func, 0);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	ret = trace_seq_printf(s, "();\n");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t
print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
			struct trace_seq *s)
{
	int i;
	int ret;
	struct ftrace_graph_ent *call = &entry->graph_ent;

	/* No overhead */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
		ret = trace_seq_printf(s, "  ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* No time */
	ret = trace_seq_printf(s, "            |  ");

	/* Function */
	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
		ret = trace_seq_printf(s, " ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	ret = seq_print_ip_sym(s, call->func, 0);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	ret = trace_seq_printf(s, "() {\n");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	return TRACE_TYPE_HANDLED;
}

static enum print_line_t
print_graph_entry(struct ftrace_graph_ent_entry *field, struct trace_seq *s,
			struct trace_iterator *iter, int cpu)
{
	int ret;
	struct trace_entry *ent = iter->ent;

	/* Pid */
	if (verif_pid(s, ent->pid, cpu) == TRACE_TYPE_PARTIAL_LINE)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Cpu */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
		ret = print_graph_cpu(s, cpu);
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* Proc */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
		ret = print_graph_proc(s, ent->pid);
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;

		ret = trace_seq_printf(s, " | ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	if (trace_branch_is_leaf(iter, field))
		return print_graph_entry_leaf(iter, field, s);
	else
		return print_graph_entry_nested(field, s);

}

static enum print_line_t
print_graph_return(struct ftrace_graph_ret *trace, struct trace_seq *s,
		   struct trace_entry *ent, int cpu)
{
	int i;
	int ret;
	unsigned long long duration = trace->rettime - trace->calltime;

	/* Must not exceed 8 characters: xxxx.yyy us */
	if (duration > 10000000ULL)
		duration = 9999999ULL;

	/* Pid */
	if (verif_pid(s, ent->pid, cpu) == TRACE_TYPE_PARTIAL_LINE)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Cpu */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
		ret = print_graph_cpu(s, cpu);
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* Proc */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
		ret = print_graph_proc(s, ent->pid);
		if (ret == TRACE_TYPE_PARTIAL_LINE)
			return TRACE_TYPE_PARTIAL_LINE;

		ret = trace_seq_printf(s, " | ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* Overhead */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
		ret = print_graph_overhead(duration, s);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	/* Duration */
	ret = print_graph_duration(duration, s);
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Closing brace */
	for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
		ret = trace_seq_printf(s, " ");
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}

	ret = trace_seq_printf(s, "}\n");
	if (!ret)
		return TRACE_TYPE_PARTIAL_LINE;

	/* Overrun */
	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
		ret = trace_seq_printf(s, " (Overruns: %lu)\n",
					trace->overrun);
		if (!ret)
			return TRACE_TYPE_PARTIAL_LINE;
	}
	return TRACE_TYPE_HANDLED;
}

enum print_line_t
print_graph_function(struct trace_iterator *iter)
{
	struct trace_seq *s = &iter->seq;
	struct trace_entry *entry = iter->ent;

	switch (entry->type) {
	case TRACE_GRAPH_ENT: {
		struct ftrace_graph_ent_entry *field;
		trace_assign_type(field, entry);
		return print_graph_entry(field, s, iter,
					 iter->cpu);
	}
	case TRACE_GRAPH_RET: {
		struct ftrace_graph_ret_entry *field;
		trace_assign_type(field, entry);
		return print_graph_return(&field->ret, s, entry, iter->cpu);
	}
	default:
		return TRACE_TYPE_UNHANDLED;
	}
}

static struct tracer graph_trace __read_mostly = {
	.name	     = "function_graph",
	.init	     = graph_trace_init,
	.reset	     = graph_trace_reset,
	.print_line = print_graph_function,
	.flags		= &tracer_flags,
};

static __init int init_graph_trace(void)
{
	return register_tracer(&graph_trace);
}

device_initcall(init_graph_trace);
Commit	Line	Data
fb52607a FW	1	/*
	2	*
	3	* Function graph tracer.
	4	* Copyright (c) 2008 Frederic Weisbecker <fweisbec@gmail.com>
	5	* Mostly borrowed from function tracer which
	6	* is Copyright (c) Steven Rostedt <srostedt@redhat.com>
	7	*
	8	*/
	9	#include <linux/debugfs.h>
	10	#include <linux/uaccess.h>
	11	#include <linux/ftrace.h>
	12	#include <linux/fs.h>
	13
	14	#include "trace.h"
	15
287b6e68	16	#define TRACE_GRAPH_INDENT 2
fb52607a	17
1a056155	18	/* Flag options */
fb52607a	19	#define TRACE_GRAPH_PRINT_OVERRUN 0x1
1a056155 FW	20	#define TRACE_GRAPH_PRINT_CPU 0x2
1a056155 FW	21	#define TRACE_GRAPH_PRINT_OVERHEAD 0x4
11e84acc	22	#define TRACE_GRAPH_PRINT_PROC 0x8
1a056155	23
fb52607a	24	static struct tracer_opt trace_opts[] = {
1a056155 FW	25	/* Display overruns ? */
	26	{ TRACER_OPT(funcgraph-overrun, TRACE_GRAPH_PRINT_OVERRUN) },
	27	/* Display CPU ? */
	28	{ TRACER_OPT(funcgraph-cpu, TRACE_GRAPH_PRINT_CPU) },
	29	/* Display Overhead ? */
	30	{ TRACER_OPT(funcgraph-overhead, TRACE_GRAPH_PRINT_OVERHEAD) },
11e84acc FW	31	/* Display proc name/pid */
11e84acc FW	32	{ TRACER_OPT(funcgraph-proc, TRACE_GRAPH_PRINT_PROC) },
fb52607a FW	33	{ } /* Empty entry */
	34	};
	35
	36	static struct tracer_flags tracer_flags = {
11e84acc	37	/* Don't display overruns and proc by default */
1a056155	38	.val = TRACE_GRAPH_PRINT_CPU \| TRACE_GRAPH_PRINT_OVERHEAD,
fb52607a FW	39	.opts = trace_opts
	40	};
	41
287b6e68	42	/* pid on the last trace processed */
437f24fb	43	static pid_t last_pid[NR_CPUS] = { [0 ... NR_CPUS-1] = -1 };
fb52607a FW	44
	45	static int graph_trace_init(struct trace_array *tr)
	46	{
660c7f9b SR	47	int cpu, ret;
660c7f9b SR	48
fb52607a FW	49	for_each_online_cpu(cpu)
	50	tracing_reset(tr, cpu);
	51
660c7f9b	52	ret = register_ftrace_graph(&trace_graph_return,
287b6e68	53	&trace_graph_entry);
660c7f9b SR	54	if (ret)
	55	return ret;
	56	tracing_start_cmdline_record();
	57
	58	return 0;
fb52607a FW	59	}
	60
	61	static void graph_trace_reset(struct trace_array *tr)
	62	{
660c7f9b SR	63	tracing_stop_cmdline_record();
660c7f9b SR	64	unregister_ftrace_graph();
fb52607a FW	65	}
fb52607a FW	66
1a056155 FW	67	static inline int log10_cpu(int nb)
	68	{
	69	if (nb / 100)
	70	return 3;
	71	if (nb / 10)
	72	return 2;
	73	return 1;
	74	}
	75
	76	static enum print_line_t
	77	print_graph_cpu(struct trace_seq *s, int cpu)
	78	{
	79	int i;
	80	int ret;
	81	int log10_this = log10_cpu(cpu);
	82	int log10_all = log10_cpu(cpus_weight_nr(cpu_online_map));
	83
	84
d51090b3 IM	85	/*
	86	* Start with a space character - to make it stand out
	87	* to the right a bit when trace output is pasted into
	88	* email:
	89	*/
	90	ret = trace_seq_printf(s, " ");
	91
	92	/*
	93	* Tricky - we space the CPU field according to the max
	94	* number of online CPUs. On a 2-cpu system it would take
	95	* a maximum of 1 digit - on a 128 cpu system it would
	96	* take up to 3 digits:
	97	*/
1a056155 FW	98	for (i = 0; i < log10_all - log10_this; i++) {
	99	ret = trace_seq_printf(s, " ");
	100	if (!ret)
	101	return TRACE_TYPE_PARTIAL_LINE;
	102	}
	103	ret = trace_seq_printf(s, "%d) ", cpu);
	104	if (!ret)
d51090b3 IM	105	return TRACE_TYPE_PARTIAL_LINE;
d51090b3 IM	106
1a056155 FW	107	return TRACE_TYPE_HANDLED;
	108	}
	109
11e84acc FW	110	#define TRACE_GRAPH_PROCINFO_LENGTH 14
	111
	112	static enum print_line_t
	113	print_graph_proc(struct trace_seq *s, pid_t pid)
	114	{
	115	int i;
	116	int ret;
	117	int len;
	118	char comm[8];
	119	int spaces = 0;
	120	/* sign + log10(MAX_INT) + '\0' */
	121	char pid_str[11];
	122
	123	strncpy(comm, trace_find_cmdline(pid), 7);
	124	comm[7] = '\0';
	125	sprintf(pid_str, "%d", pid);
	126
	127	/* 1 stands for the "-" character */
	128	len = strlen(comm) + strlen(pid_str) + 1;
	129
	130	if (len < TRACE_GRAPH_PROCINFO_LENGTH)
	131	spaces = TRACE_GRAPH_PROCINFO_LENGTH - len;
	132
	133	/* First spaces to align center */
	134	for (i = 0; i < spaces / 2; i++) {
	135	ret = trace_seq_printf(s, " ");
	136	if (!ret)
	137	return TRACE_TYPE_PARTIAL_LINE;
	138	}
	139
	140	ret = trace_seq_printf(s, "%s-%s", comm, pid_str);
	141	if (!ret)
	142	return TRACE_TYPE_PARTIAL_LINE;
	143
	144	/* Last spaces to align center */
	145	for (i = 0; i < spaces - (spaces / 2); i++) {
	146	ret = trace_seq_printf(s, " ");
	147	if (!ret)
	148	return TRACE_TYPE_PARTIAL_LINE;
	149	}
	150	return TRACE_TYPE_HANDLED;
	151	}
	152
1a056155	153
287b6e68	154	/* If the pid changed since the last trace, output this event */
11e84acc FW	155	static enum print_line_t
11e84acc FW	156	verif_pid(struct trace_seq *s, pid_t pid, int cpu)
287b6e68	157	{
d51090b3 IM	158	pid_t prev_pid;
d51090b3 IM	159	int ret;
660c7f9b	160
437f24fb	161	if (last_pid[cpu] != -1 && last_pid[cpu] == pid)
11e84acc	162	return TRACE_TYPE_HANDLED;
fb52607a	163
d51090b3	164	prev_pid = last_pid[cpu];
437f24fb	165	last_pid[cpu] = pid;
d51090b3	166
d51090b3 IM	167	/*
	168	* Context-switch trace line:
	169
	170	------------------------------------------
	171	\| 1) migration/0--1 => sshd-1755
	172	------------------------------------------
	173
	174	*/
	175	ret = trace_seq_printf(s,
11e84acc FW	176	"\n ------------------------------------------\n \|");
	177	if (!ret)
	178	TRACE_TYPE_PARTIAL_LINE;
	179
	180	ret = print_graph_cpu(s, cpu);
	181	if (ret == TRACE_TYPE_PARTIAL_LINE)
	182	TRACE_TYPE_PARTIAL_LINE;
	183
	184	ret = print_graph_proc(s, prev_pid);
	185	if (ret == TRACE_TYPE_PARTIAL_LINE)
	186	TRACE_TYPE_PARTIAL_LINE;
	187
	188	ret = trace_seq_printf(s, " => ");
	189	if (!ret)
	190	TRACE_TYPE_PARTIAL_LINE;
	191
	192	ret = print_graph_proc(s, pid);
	193	if (ret == TRACE_TYPE_PARTIAL_LINE)
	194	TRACE_TYPE_PARTIAL_LINE;
	195
	196	ret = trace_seq_printf(s,
	197	"\n ------------------------------------------\n\n");
	198	if (!ret)
	199	TRACE_TYPE_PARTIAL_LINE;
	200
d51090b3	201	return ret;
287b6e68 FW	202	}
287b6e68 FW	203
83a8df61 FW	204	static bool
	205	trace_branch_is_leaf(struct trace_iterator *iter,
	206	struct ftrace_graph_ent_entry *curr)
	207	{
	208	struct ring_buffer_iter *ring_iter;
	209	struct ring_buffer_event *event;
	210	struct ftrace_graph_ret_entry *next;
	211
	212	ring_iter = iter->buffer_iter[iter->cpu];
	213
	214	if (!ring_iter)
	215	return false;
	216
1a056155	217	event = ring_buffer_iter_peek(ring_iter, NULL);
83a8df61 FW	218
	219	if (!event)
	220	return false;
	221
	222	next = ring_buffer_event_data(event);
	223
	224	if (next->ent.type != TRACE_GRAPH_RET)
	225	return false;
	226
	227	if (curr->ent.pid != next->ent.pid \|\|
	228	curr->graph_ent.func != next->ret.func)
	229	return false;
	230
	231	return true;
	232	}
	233
	234
	235	static inline int
	236	print_graph_duration(unsigned long long duration, struct trace_seq *s)
	237	{
	238	unsigned long nsecs_rem = do_div(duration, 1000);
d51090b3	239	return trace_seq_printf(s, "%4llu.%3lu us \| ", duration, nsecs_rem);
83a8df61 FW	240	}
	241
	242	/* Signal a overhead of time execution to the output */
	243	static int
	244	print_graph_overhead(unsigned long long duration, struct trace_seq *s)
	245	{
	246	/* Duration exceeded 100 msecs */
	247	if (duration > 100000ULL)
	248	return trace_seq_printf(s, "! ");
	249
	250	/* Duration exceeded 10 msecs */
	251	if (duration > 10000ULL)
	252	return trace_seq_printf(s, "+ ");
	253
	254	return trace_seq_printf(s, " ");
	255	}
	256
	257	/* Case of a leaf function on its call entry */
287b6e68	258	static enum print_line_t
83a8df61 FW	259	print_graph_entry_leaf(struct trace_iterator *iter,
83a8df61 FW	260	struct ftrace_graph_ent_entry entry, struct trace_seq s)
fb52607a	261	{
83a8df61 FW	262	struct ftrace_graph_ret_entry *ret_entry;
	263	struct ftrace_graph_ret *graph_ret;
	264	struct ring_buffer_event *event;
	265	struct ftrace_graph_ent *call;
	266	unsigned long long duration;
fb52607a	267	int ret;
1a056155	268	int i;
fb52607a	269
83a8df61 FW	270	event = ring_buffer_read(iter->buffer_iter[iter->cpu], NULL);
	271	ret_entry = ring_buffer_event_data(event);
	272	graph_ret = &ret_entry->ret;
	273	call = &entry->graph_ent;
	274	duration = graph_ret->rettime - graph_ret->calltime;
	275
1a056155 FW	276	/* Must not exceed 8 characters: 9999.999 us */
	277	if (duration > 10000000ULL)
	278	duration = 9999999ULL;
	279
83a8df61	280	/* Overhead */
1a056155 FW	281	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
	282	ret = print_graph_overhead(duration, s);
	283	if (!ret)
	284	return TRACE_TYPE_PARTIAL_LINE;
	285	}
	286
	287	/* Duration */
	288	ret = print_graph_duration(duration, s);
83a8df61	289	if (!ret)
437f24fb SR	290	return TRACE_TYPE_PARTIAL_LINE;
437f24fb SR	291
83a8df61 FW	292	/* Function */
	293	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
	294	ret = trace_seq_printf(s, " ");
	295	if (!ret)
	296	return TRACE_TYPE_PARTIAL_LINE;
	297	}
	298
	299	ret = seq_print_ip_sym(s, call->func, 0);
	300	if (!ret)
	301	return TRACE_TYPE_PARTIAL_LINE;
	302
1a056155	303	ret = trace_seq_printf(s, "();\n");
83a8df61 FW	304	if (!ret)
	305	return TRACE_TYPE_PARTIAL_LINE;
	306
	307	return TRACE_TYPE_HANDLED;
	308	}
	309
	310	static enum print_line_t
	311	print_graph_entry_nested(struct ftrace_graph_ent_entry *entry,
	312	struct trace_seq *s)
	313	{
	314	int i;
	315	int ret;
	316	struct ftrace_graph_ent *call = &entry->graph_ent;
	317
	318	/* No overhead */
1a056155 FW	319	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
	320	ret = trace_seq_printf(s, " ");
	321	if (!ret)
	322	return TRACE_TYPE_PARTIAL_LINE;
	323	}
	324
	325	/* No time */
d51090b3	326	ret = trace_seq_printf(s, " \| ");
83a8df61 FW	327
83a8df61 FW	328	/* Function */
287b6e68 FW	329	for (i = 0; i < call->depth * TRACE_GRAPH_INDENT; i++) {
287b6e68 FW	330	ret = trace_seq_printf(s, " ");
fb52607a FW	331	if (!ret)
fb52607a FW	332	return TRACE_TYPE_PARTIAL_LINE;
287b6e68 FW	333	}
	334
	335	ret = seq_print_ip_sym(s, call->func, 0);
	336	if (!ret)
	337	return TRACE_TYPE_PARTIAL_LINE;
	338
1a056155	339	ret = trace_seq_printf(s, "() {\n");
83a8df61 FW	340	if (!ret)
	341	return TRACE_TYPE_PARTIAL_LINE;
	342
287b6e68 FW	343	return TRACE_TYPE_HANDLED;
	344	}
	345
83a8df61 FW	346	static enum print_line_t
	347	print_graph_entry(struct ftrace_graph_ent_entry field, struct trace_seq s,
	348	struct trace_iterator *iter, int cpu)
	349	{
	350	int ret;
	351	struct trace_entry *ent = iter->ent;
	352
1a056155	353	/* Pid */
11e84acc	354	if (verif_pid(s, ent->pid, cpu) == TRACE_TYPE_PARTIAL_LINE)
83a8df61 FW	355	return TRACE_TYPE_PARTIAL_LINE;
83a8df61 FW	356
1a056155 FW	357	/* Cpu */
	358	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
	359	ret = print_graph_cpu(s, cpu);
11e84acc FW	360	if (ret == TRACE_TYPE_PARTIAL_LINE)
	361	return TRACE_TYPE_PARTIAL_LINE;
	362	}
	363
	364	/* Proc */
	365	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
	366	ret = print_graph_proc(s, ent->pid);
	367	if (ret == TRACE_TYPE_PARTIAL_LINE)
	368	return TRACE_TYPE_PARTIAL_LINE;
	369
	370	ret = trace_seq_printf(s, " \| ");
1a056155 FW	371	if (!ret)
	372	return TRACE_TYPE_PARTIAL_LINE;
	373	}
83a8df61 FW	374
	375	if (trace_branch_is_leaf(iter, field))
	376	return print_graph_entry_leaf(iter, field, s);
	377	else
	378	return print_graph_entry_nested(field, s);
	379
	380	}
	381
287b6e68 FW	382	static enum print_line_t
287b6e68 FW	383	print_graph_return(struct ftrace_graph_ret trace, struct trace_seq s,
437f24fb	384	struct trace_entry *ent, int cpu)
287b6e68 FW	385	{
	386	int i;
	387	int ret;
83a8df61	388	unsigned long long duration = trace->rettime - trace->calltime;
287b6e68	389
1a056155 FW	390	/* Must not exceed 8 characters: xxxx.yyy us */
	391	if (duration > 10000000ULL)
	392	duration = 9999999ULL;
	393
83a8df61	394	/* Pid */
11e84acc	395	if (verif_pid(s, ent->pid, cpu) == TRACE_TYPE_PARTIAL_LINE)
437f24fb SR	396	return TRACE_TYPE_PARTIAL_LINE;
437f24fb SR	397
83a8df61	398	/* Cpu */
1a056155 FW	399	if (tracer_flags.val & TRACE_GRAPH_PRINT_CPU) {
1a056155 FW	400	ret = print_graph_cpu(s, cpu);
11e84acc FW	401	if (ret == TRACE_TYPE_PARTIAL_LINE)
	402	return TRACE_TYPE_PARTIAL_LINE;
	403	}
	404
	405	/* Proc */
	406	if (tracer_flags.val & TRACE_GRAPH_PRINT_PROC) {
	407	ret = print_graph_proc(s, ent->pid);
	408	if (ret == TRACE_TYPE_PARTIAL_LINE)
	409	return TRACE_TYPE_PARTIAL_LINE;
	410
	411	ret = trace_seq_printf(s, " \| ");
1a056155 FW	412	if (!ret)
	413	return TRACE_TYPE_PARTIAL_LINE;
	414	}
fb52607a	415
83a8df61	416	/* Overhead */
1a056155 FW	417	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERHEAD) {
	418	ret = print_graph_overhead(duration, s);
	419	if (!ret)
	420	return TRACE_TYPE_PARTIAL_LINE;
	421	}
	422
	423	/* Duration */
	424	ret = print_graph_duration(duration, s);
83a8df61 FW	425	if (!ret)
	426	return TRACE_TYPE_PARTIAL_LINE;
	427
	428	/* Closing brace */
287b6e68 FW	429	for (i = 0; i < trace->depth * TRACE_GRAPH_INDENT; i++) {
287b6e68 FW	430	ret = trace_seq_printf(s, " ");
fb52607a FW	431	if (!ret)
fb52607a FW	432	return TRACE_TYPE_PARTIAL_LINE;
287b6e68 FW	433	}
287b6e68 FW	434
1a056155	435	ret = trace_seq_printf(s, "}\n");
287b6e68 FW	436	if (!ret)
287b6e68 FW	437	return TRACE_TYPE_PARTIAL_LINE;
fb52607a	438
83a8df61	439	/* Overrun */
287b6e68 FW	440	if (tracer_flags.val & TRACE_GRAPH_PRINT_OVERRUN) {
	441	ret = trace_seq_printf(s, " (Overruns: %lu)\n",
	442	trace->overrun);
fb52607a FW	443	if (!ret)
fb52607a FW	444	return TRACE_TYPE_PARTIAL_LINE;
287b6e68 FW	445	}
	446	return TRACE_TYPE_HANDLED;
	447	}
	448
	449	enum print_line_t
	450	print_graph_function(struct trace_iterator *iter)
	451	{
	452	struct trace_seq *s = &iter->seq;
	453	struct trace_entry *entry = iter->ent;
fb52607a	454
287b6e68 FW	455	switch (entry->type) {
	456	case TRACE_GRAPH_ENT: {
	457	struct ftrace_graph_ent_entry *field;
	458	trace_assign_type(field, entry);
83a8df61	459	return print_graph_entry(field, s, iter,
437f24fb	460	iter->cpu);
287b6e68 FW	461	}
	462	case TRACE_GRAPH_RET: {
	463	struct ftrace_graph_ret_entry *field;
	464	trace_assign_type(field, entry);
437f24fb	465	return print_graph_return(&field->ret, s, entry, iter->cpu);
287b6e68 FW	466	}
	467	default:
	468	return TRACE_TYPE_UNHANDLED;
fb52607a	469	}
fb52607a FW	470	}
	471
	472	static struct tracer graph_trace __read_mostly = {
83a8df61	473	.name = "function_graph",
fb52607a FW	474	.init = graph_trace_init,
	475	.reset = graph_trace_reset,
	476	.print_line = print_graph_function,
	477	.flags = &tracer_flags,
	478	};
	479
	480	static __init int init_graph_trace(void)
	481	{
	482	return register_tracer(&graph_trace);
	483	}
	484
	485	device_initcall(init_graph_trace);