blob: b2fa5df64a62b50393488152882ac9f67ab8c593 (
plain)
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
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
|
/**
* @file oprof.c
*
* @remark Copyright 2002 OProfile authors
* @remark Read the file COPYING
*
* @author John Levon <levon@movementarian.org>
*/
#include <linux/kernel.h>
#include <linux/module.h>
#include <linux/init.h>
#include <linux/oprofile.h>
#include <linux/moduleparam.h>
#include <linux/workqueue.h>
#include <linux/time.h>
#include <asm/mutex.h>
#include "oprof.h"
#include "event_buffer.h"
#include "cpu_buffer.h"
#include "buffer_sync.h"
#include "oprofile_stats.h"
static unsigned long is_setup;
static void switch_worker(struct work_struct *work);
static DECLARE_DELAYED_WORK(switch_work, switch_worker);
static DEFINE_MUTEX(start_mutex);
struct oprofile_operations oprofile_ops;
unsigned long timeout_jiffies;
unsigned long oprofile_started;
unsigned long backtrace_depth;
/* Multiplexing defaults at 1 msec*/
/* timer
0 - use performance monitoring hardware if available
1 - use the timer int mechanism regardless
*/
static int timer = 0;
int oprofile_setup(void)
{
int err;
mutex_lock(&start_mutex);
if ((err = alloc_cpu_buffers()))
goto out;
if ((err = alloc_event_buffer()))
goto out1;
if (oprofile_ops.setup && (err = oprofile_ops.setup()))
goto out2;
/* Note even though this starts part of the
* profiling overhead, it's necessary to prevent
* us missing task deaths and eventually oopsing
* when trying to process the event buffer.
*/
if (oprofile_ops.sync_start) {
int sync_ret = oprofile_ops.sync_start();
switch (sync_ret) {
case 0:
goto post_sync;
case 1:
goto do_generic;
case -1:
goto out3;
default:
goto out3;
}
}
do_generic:
if ((err = sync_start()))
goto out3;
post_sync:
is_setup = 1;
mutex_unlock(&start_mutex);
return 0;
out3:
if (oprofile_ops.shutdown)
oprofile_ops.shutdown();
out2:
free_event_buffer();
out1:
free_cpu_buffers();
out:
mutex_unlock(&start_mutex);
return err;
}
static void start_switch_worker(void)
{
schedule_delayed_work(&switch_work, timeout_jiffies);
}
static void switch_worker(struct work_struct *work)
{
if (!oprofile_ops.switch_events())
start_switch_worker();
}
/* Actually start profiling (echo 1>/dev/oprofile/enable) */
int oprofile_start(void)
{
int err = -EINVAL;
mutex_lock(&start_mutex);
if (!is_setup)
goto out;
err = 0;
if (oprofile_started)
goto out;
oprofile_reset_stats();
if ((err = oprofile_ops.start()))
goto out;
if (oprofile_ops.switch_events)
start_switch_worker();
oprofile_started = 1;
out:
mutex_unlock(&start_mutex);
return err;
}
/* echo 0>/dev/oprofile/enable */
void oprofile_stop(void)
{
mutex_lock(&start_mutex);
if (!oprofile_started)
goto out;
oprofile_ops.stop();
oprofile_started = 0;
cancel_delayed_work_sync(&switch_work);
/* wake up the daemon to read what remains */
wake_up_buffer_waiter();
out:
mutex_unlock(&start_mutex);
}
void oprofile_shutdown(void)
{
mutex_lock(&start_mutex);
if (oprofile_ops.sync_stop) {
int sync_ret = oprofile_ops.sync_stop();
switch (sync_ret) {
case 0:
goto post_sync;
case 1:
goto do_generic;
default:
goto post_sync;
}
}
do_generic:
sync_stop();
post_sync:
if (oprofile_ops.shutdown)
oprofile_ops.shutdown();
is_setup = 0;
free_event_buffer();
free_cpu_buffers();
mutex_unlock(&start_mutex);
}
/* User inputs in ms, converts to jiffies */
int oprofile_set_timeout(unsigned long val_msec)
{
int err = 0;
mutex_lock(&start_mutex);
if (oprofile_started) {
err = -EBUSY;
goto out;
}
if (!oprofile_ops.switch_events) {
err = -EINVAL;
goto out;
}
timeout_jiffies = msecs_to_jiffies(val_msec);
if (timeout_jiffies == MAX_JIFFY_OFFSET)
timeout_jiffies = msecs_to_jiffies(1);
out:
mutex_unlock(&start_mutex);
return err;
}
int oprofile_set_backtrace(unsigned long val)
{
int err = 0;
mutex_lock(&start_mutex);
if (oprofile_started) {
err = -EBUSY;
goto out;
}
if (!oprofile_ops.backtrace) {
err = -EINVAL;
goto out;
}
backtrace_depth = val;
out:
mutex_unlock(&start_mutex);
return err;
}
static void __init oprofile_switch_timer_init(void)
{
timeout_jiffies = msecs_to_jiffies(1);
}
static int __init oprofile_init(void)
{
int err;
oprofile_switch_timer_init();
err = oprofile_arch_init(&oprofile_ops);
if (err < 0 || timer) {
printk(KERN_INFO "oprofile: using timer interrupt.\n");
oprofile_timer_init(&oprofile_ops);
}
err = oprofilefs_register();
if (err)
oprofile_arch_exit();
return err;
}
static void __exit oprofile_exit(void)
{
oprofilefs_unregister();
oprofile_arch_exit();
}
module_init(oprofile_init);
module_exit(oprofile_exit);
module_param_named(timer, timer, int, 0644);
MODULE_PARM_DESC(timer, "force use of timer interrupt");
MODULE_LICENSE("GPL");
MODULE_AUTHOR("John Levon <levon@movementarian.org>");
MODULE_DESCRIPTION("OProfile system profiler");
|
