diff options
Diffstat (limited to 'drivers/oprofile/oprof.c')
-rw-r--r-- | drivers/oprofile/oprof.c | 188 |
1 files changed, 188 insertions, 0 deletions
diff --git a/drivers/oprofile/oprof.c b/drivers/oprofile/oprof.c new file mode 100644 index 000000000000..b3f1cd6a24c1 --- /dev/null +++ b/drivers/oprofile/oprof.c | |||
@@ -0,0 +1,188 @@ | |||
1 | /** | ||
2 | * @file oprof.c | ||
3 | * | ||
4 | * @remark Copyright 2002 OProfile authors | ||
5 | * @remark Read the file COPYING | ||
6 | * | ||
7 | * @author John Levon <levon@movementarian.org> | ||
8 | */ | ||
9 | |||
10 | #include <linux/kernel.h> | ||
11 | #include <linux/module.h> | ||
12 | #include <linux/init.h> | ||
13 | #include <linux/oprofile.h> | ||
14 | #include <linux/moduleparam.h> | ||
15 | #include <asm/semaphore.h> | ||
16 | |||
17 | #include "oprof.h" | ||
18 | #include "event_buffer.h" | ||
19 | #include "cpu_buffer.h" | ||
20 | #include "buffer_sync.h" | ||
21 | #include "oprofile_stats.h" | ||
22 | |||
23 | struct oprofile_operations oprofile_ops; | ||
24 | |||
25 | unsigned long oprofile_started; | ||
26 | unsigned long backtrace_depth; | ||
27 | static unsigned long is_setup; | ||
28 | static DECLARE_MUTEX(start_sem); | ||
29 | |||
30 | /* timer | ||
31 | 0 - use performance monitoring hardware if available | ||
32 | 1 - use the timer int mechanism regardless | ||
33 | */ | ||
34 | static int timer = 0; | ||
35 | |||
36 | int oprofile_setup(void) | ||
37 | { | ||
38 | int err; | ||
39 | |||
40 | down(&start_sem); | ||
41 | |||
42 | if ((err = alloc_cpu_buffers())) | ||
43 | goto out; | ||
44 | |||
45 | if ((err = alloc_event_buffer())) | ||
46 | goto out1; | ||
47 | |||
48 | if (oprofile_ops.setup && (err = oprofile_ops.setup())) | ||
49 | goto out2; | ||
50 | |||
51 | /* Note even though this starts part of the | ||
52 | * profiling overhead, it's necessary to prevent | ||
53 | * us missing task deaths and eventually oopsing | ||
54 | * when trying to process the event buffer. | ||
55 | */ | ||
56 | if ((err = sync_start())) | ||
57 | goto out3; | ||
58 | |||
59 | is_setup = 1; | ||
60 | up(&start_sem); | ||
61 | return 0; | ||
62 | |||
63 | out3: | ||
64 | if (oprofile_ops.shutdown) | ||
65 | oprofile_ops.shutdown(); | ||
66 | out2: | ||
67 | free_event_buffer(); | ||
68 | out1: | ||
69 | free_cpu_buffers(); | ||
70 | out: | ||
71 | up(&start_sem); | ||
72 | return err; | ||
73 | } | ||
74 | |||
75 | |||
76 | /* Actually start profiling (echo 1>/dev/oprofile/enable) */ | ||
77 | int oprofile_start(void) | ||
78 | { | ||
79 | int err = -EINVAL; | ||
80 | |||
81 | down(&start_sem); | ||
82 | |||
83 | if (!is_setup) | ||
84 | goto out; | ||
85 | |||
86 | err = 0; | ||
87 | |||
88 | if (oprofile_started) | ||
89 | goto out; | ||
90 | |||
91 | oprofile_reset_stats(); | ||
92 | |||
93 | if ((err = oprofile_ops.start())) | ||
94 | goto out; | ||
95 | |||
96 | oprofile_started = 1; | ||
97 | out: | ||
98 | up(&start_sem); | ||
99 | return err; | ||
100 | } | ||
101 | |||
102 | |||
103 | /* echo 0>/dev/oprofile/enable */ | ||
104 | void oprofile_stop(void) | ||
105 | { | ||
106 | down(&start_sem); | ||
107 | if (!oprofile_started) | ||
108 | goto out; | ||
109 | oprofile_ops.stop(); | ||
110 | oprofile_started = 0; | ||
111 | /* wake up the daemon to read what remains */ | ||
112 | wake_up_buffer_waiter(); | ||
113 | out: | ||
114 | up(&start_sem); | ||
115 | } | ||
116 | |||
117 | |||
118 | void oprofile_shutdown(void) | ||
119 | { | ||
120 | down(&start_sem); | ||
121 | sync_stop(); | ||
122 | if (oprofile_ops.shutdown) | ||
123 | oprofile_ops.shutdown(); | ||
124 | is_setup = 0; | ||
125 | free_event_buffer(); | ||
126 | free_cpu_buffers(); | ||
127 | up(&start_sem); | ||
128 | } | ||
129 | |||
130 | |||
131 | int oprofile_set_backtrace(unsigned long val) | ||
132 | { | ||
133 | int err = 0; | ||
134 | |||
135 | down(&start_sem); | ||
136 | |||
137 | if (oprofile_started) { | ||
138 | err = -EBUSY; | ||
139 | goto out; | ||
140 | } | ||
141 | |||
142 | if (!oprofile_ops.backtrace) { | ||
143 | err = -EINVAL; | ||
144 | goto out; | ||
145 | } | ||
146 | |||
147 | backtrace_depth = val; | ||
148 | |||
149 | out: | ||
150 | up(&start_sem); | ||
151 | return err; | ||
152 | } | ||
153 | |||
154 | static int __init oprofile_init(void) | ||
155 | { | ||
156 | int err; | ||
157 | |||
158 | err = oprofile_arch_init(&oprofile_ops); | ||
159 | |||
160 | if (err < 0 || timer) { | ||
161 | printk(KERN_INFO "oprofile: using timer interrupt.\n"); | ||
162 | oprofile_timer_init(&oprofile_ops); | ||
163 | } | ||
164 | |||
165 | err = oprofilefs_register(); | ||
166 | if (err) | ||
167 | oprofile_arch_exit(); | ||
168 | |||
169 | return err; | ||
170 | } | ||
171 | |||
172 | |||
173 | static void __exit oprofile_exit(void) | ||
174 | { | ||
175 | oprofilefs_unregister(); | ||
176 | oprofile_arch_exit(); | ||
177 | } | ||
178 | |||
179 | |||
180 | module_init(oprofile_init); | ||
181 | module_exit(oprofile_exit); | ||
182 | |||
183 | module_param_named(timer, timer, int, 0644); | ||
184 | MODULE_PARM_DESC(timer, "force use of timer interrupt"); | ||
185 | |||
186 | MODULE_LICENSE("GPL"); | ||
187 | MODULE_AUTHOR("John Levon <levon@movementarian.org>"); | ||
188 | MODULE_DESCRIPTION("OProfile system profiler"); | ||