aboutsummaryrefslogtreecommitdiffstats
path: root/kernel/trace/trace_unlikely.c
blob: 94932696069ff7f95ded475856ca7b21d2026f9b (plain) (blame)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
/*
 * unlikely profiler
 *
 * Copyright (C) 2008 Steven Rostedt <srostedt@redhat.com>
 */
#include <linux/kallsyms.h>
#include <linux/seq_file.h>
#include <linux/spinlock.h>
#include <linux/debugfs.h>
#include <linux/uaccess.h>
#include <linux/module.h>
#include <linux/ftrace.h>
#include <linux/hash.h>
#include <linux/fs.h>
#include <asm/local.h>
#include "trace.h"

void ftrace_likely_update(struct ftrace_likely_data *f, int val, int expect)
{
	/* FIXME: Make this atomic! */
	if (val == expect)
		f->correct++;
	else
		f->incorrect++;
}
EXPORT_SYMBOL(ftrace_likely_update);

struct ftrace_pointer {
	void		*start;
	void		*stop;
};

static void *
t_next(struct seq_file *m, void *v, loff_t *pos)
{
	struct ftrace_pointer *f = m->private;
	struct ftrace_likely_data *p = v;

	(*pos)++;

	if (v == (void *)1)
		return f->start;

	++p;

	if ((void *)p >= (void *)f->stop)
		return NULL;

	return p;
}

static void *t_start(struct seq_file *m, loff_t *pos)
{
	void *t = (void *)1;
	loff_t l = 0;

	for (; t && l < *pos; t = t_next(m, t, &l))
		;

	return t;
}

static void t_stop(struct seq_file *m, void *p)
{
}

static int t_show(struct seq_file *m, void *v)
{
	struct ftrace_likely_data *p = v;
	const char *f;
	unsigned long percent;

	if (v == (void *)1) {
		seq_printf(m, " correct incorrect  %% "
			      "       Function                "
			      "  File              Line\n"
			      " ------- ---------  - "
			      "       --------                "
			      "  ----              ----\n");
		return 0;
	}

	/* Only print the file, not the path */
	f = p->file + strlen(p->file);
	while (f >= p->file && *f != '/')
		f--;
	f++;

	if (p->correct) {
		percent = p->incorrect * 100;
		percent /= p->correct + p->incorrect;
	} else
		percent = p->incorrect ? 100 : 0;

	seq_printf(m, "%8lu %8lu %3lu ", p->correct, p->incorrect, percent);
	seq_printf(m, "%-30.30s %-20.20s %d\n", p->func, f, p->line);
	return 0;
}

static struct seq_operations tracing_likely_seq_ops = {
	.start		= t_start,
	.next		= t_next,
	.stop		= t_stop,
	.show		= t_show,
};

static int tracing_likely_open(struct inode *inode, struct file *file)
{
	int ret;

	ret = seq_open(file, &tracing_likely_seq_ops);
	if (!ret) {
		struct seq_file *m = file->private_data;
		m->private = (void *)inode->i_private;
	}

	return ret;
}

static struct file_operations tracing_likely_fops = {
	.open		= tracing_likely_open,
	.read		= seq_read,
	.llseek		= seq_lseek,
};

extern unsigned long __start_likely_profile[];
extern unsigned long __stop_likely_profile[];
extern unsigned long __start_unlikely_profile[];
extern unsigned long __stop_unlikely_profile[];

static struct ftrace_pointer ftrace_likely_pos = {
	.start			= __start_likely_profile,
	.stop			= __stop_likely_profile,
};

static struct ftrace_pointer ftrace_unlikely_pos = {
	.start			= __start_unlikely_profile,
	.stop			= __stop_unlikely_profile,
};

static __init int ftrace_unlikely_init(void)
{
	struct dentry *d_tracer;
	struct dentry *entry;

	d_tracer = tracing_init_dentry();

	entry = debugfs_create_file("profile_likely", 0444, d_tracer,
				    &ftrace_likely_pos,
				    &tracing_likely_fops);
	if (!entry)
		pr_warning("Could not create debugfs 'profile_likely' entry\n");

	entry = debugfs_create_file("profile_unlikely", 0444, d_tracer,
				    &ftrace_unlikely_pos,
				    &tracing_likely_fops);
	if (!entry)
		pr_warning("Could not create debugfs"
			   " 'profile_unlikely' entry\n");

	return 0;
}

device_initcall(ftrace_unlikely_init);