Commit | Line | Data |
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1da177e4 LT |
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> | |
4d4036e0 JY |
15 | #include <linux/workqueue.h> |
16 | #include <linux/time.h> | |
59cc185a | 17 | #include <asm/mutex.h> |
1da177e4 LT |
18 | |
19 | #include "oprof.h" | |
20 | #include "event_buffer.h" | |
21 | #include "cpu_buffer.h" | |
22 | #include "buffer_sync.h" | |
23 | #include "oprofile_stats.h" | |
c92960fc | 24 | |
1da177e4 LT |
25 | struct oprofile_operations oprofile_ops; |
26 | ||
27 | unsigned long oprofile_started; | |
bd2172f5 | 28 | unsigned long oprofile_backtrace_depth; |
4c168eaf RR |
29 | static unsigned long is_setup; |
30 | static DEFINE_MUTEX(start_mutex); | |
1da177e4 LT |
31 | |
32 | /* timer | |
33 | 0 - use performance monitoring hardware if available | |
34 | 1 - use the timer int mechanism regardless | |
35 | */ | |
36 | static int timer = 0; | |
37 | ||
38 | int oprofile_setup(void) | |
39 | { | |
40 | int err; | |
c92960fc | 41 | |
59cc185a | 42 | mutex_lock(&start_mutex); |
1da177e4 LT |
43 | |
44 | if ((err = alloc_cpu_buffers())) | |
45 | goto out; | |
46 | ||
47 | if ((err = alloc_event_buffer())) | |
48 | goto out1; | |
c92960fc | 49 | |
1da177e4 LT |
50 | if (oprofile_ops.setup && (err = oprofile_ops.setup())) |
51 | goto out2; | |
c92960fc | 52 | |
1da177e4 LT |
53 | /* Note even though this starts part of the |
54 | * profiling overhead, it's necessary to prevent | |
55 | * us missing task deaths and eventually oopsing | |
56 | * when trying to process the event buffer. | |
57 | */ | |
1474855d BN |
58 | if (oprofile_ops.sync_start) { |
59 | int sync_ret = oprofile_ops.sync_start(); | |
60 | switch (sync_ret) { | |
61 | case 0: | |
62 | goto post_sync; | |
63 | case 1: | |
64 | goto do_generic; | |
65 | case -1: | |
66 | goto out3; | |
67 | default: | |
68 | goto out3; | |
69 | } | |
70 | } | |
71 | do_generic: | |
1da177e4 LT |
72 | if ((err = sync_start())) |
73 | goto out3; | |
74 | ||
1474855d | 75 | post_sync: |
1da177e4 | 76 | is_setup = 1; |
59cc185a | 77 | mutex_unlock(&start_mutex); |
1da177e4 | 78 | return 0; |
c92960fc | 79 | |
1da177e4 LT |
80 | out3: |
81 | if (oprofile_ops.shutdown) | |
82 | oprofile_ops.shutdown(); | |
83 | out2: | |
84 | free_event_buffer(); | |
85 | out1: | |
86 | free_cpu_buffers(); | |
87 | out: | |
59cc185a | 88 | mutex_unlock(&start_mutex); |
1da177e4 LT |
89 | return err; |
90 | } | |
91 | ||
4d4036e0 JY |
92 | #ifdef CONFIG_OPROFILE_EVENT_MULTIPLEX |
93 | ||
a5659d17 RR |
94 | static void switch_worker(struct work_struct *work); |
95 | static DECLARE_DELAYED_WORK(switch_work, switch_worker); | |
96 | ||
4d4036e0 JY |
97 | static void start_switch_worker(void) |
98 | { | |
a5659d17 RR |
99 | if (oprofile_ops.switch_events) |
100 | schedule_delayed_work(&switch_work, oprofile_time_slice); | |
101 | } | |
102 | ||
103 | static void stop_switch_worker(void) | |
104 | { | |
105 | cancel_delayed_work_sync(&switch_work); | |
4d4036e0 JY |
106 | } |
107 | ||
108 | static void switch_worker(struct work_struct *work) | |
109 | { | |
1b294f59 RR |
110 | if (oprofile_ops.switch_events()) |
111 | return; | |
112 | ||
113 | atomic_inc(&oprofile_stats.multiplex_counter); | |
114 | start_switch_worker(); | |
4d4036e0 JY |
115 | } |
116 | ||
a5659d17 RR |
117 | /* User inputs in ms, converts to jiffies */ |
118 | int oprofile_set_timeout(unsigned long val_msec) | |
119 | { | |
120 | int err = 0; | |
121 | unsigned long time_slice; | |
122 | ||
123 | mutex_lock(&start_mutex); | |
124 | ||
125 | if (oprofile_started) { | |
126 | err = -EBUSY; | |
127 | goto out; | |
128 | } | |
129 | ||
130 | if (!oprofile_ops.switch_events) { | |
131 | err = -EINVAL; | |
132 | goto out; | |
133 | } | |
134 | ||
135 | time_slice = msecs_to_jiffies(val_msec); | |
136 | if (time_slice == MAX_JIFFY_OFFSET) { | |
137 | err = -EINVAL; | |
138 | goto out; | |
139 | } | |
140 | ||
141 | oprofile_time_slice = time_slice; | |
142 | ||
143 | out: | |
144 | mutex_unlock(&start_mutex); | |
145 | return err; | |
146 | ||
147 | } | |
148 | ||
149 | #else | |
150 | ||
151 | static inline void start_switch_worker(void) { } | |
152 | static inline void stop_switch_worker(void) { } | |
153 | ||
4d4036e0 | 154 | #endif |
1da177e4 LT |
155 | |
156 | /* Actually start profiling (echo 1>/dev/oprofile/enable) */ | |
157 | int oprofile_start(void) | |
158 | { | |
159 | int err = -EINVAL; | |
c92960fc | 160 | |
59cc185a | 161 | mutex_lock(&start_mutex); |
6a18037d | 162 | |
1da177e4 LT |
163 | if (!is_setup) |
164 | goto out; | |
165 | ||
c92960fc RR |
166 | err = 0; |
167 | ||
1da177e4 LT |
168 | if (oprofile_started) |
169 | goto out; | |
c92960fc | 170 | |
1da177e4 LT |
171 | oprofile_reset_stats(); |
172 | ||
173 | if ((err = oprofile_ops.start())) | |
174 | goto out; | |
175 | ||
a5659d17 | 176 | start_switch_worker(); |
4d4036e0 | 177 | |
1da177e4 LT |
178 | oprofile_started = 1; |
179 | out: | |
59cc185a | 180 | mutex_unlock(&start_mutex); |
1da177e4 LT |
181 | return err; |
182 | } | |
183 | ||
c92960fc | 184 | |
1da177e4 LT |
185 | /* echo 0>/dev/oprofile/enable */ |
186 | void oprofile_stop(void) | |
187 | { | |
59cc185a | 188 | mutex_lock(&start_mutex); |
1da177e4 LT |
189 | if (!oprofile_started) |
190 | goto out; | |
191 | oprofile_ops.stop(); | |
192 | oprofile_started = 0; | |
4d4036e0 | 193 | |
a5659d17 | 194 | stop_switch_worker(); |
4d4036e0 | 195 | |
1da177e4 LT |
196 | /* wake up the daemon to read what remains */ |
197 | wake_up_buffer_waiter(); | |
198 | out: | |
59cc185a | 199 | mutex_unlock(&start_mutex); |
1da177e4 LT |
200 | } |
201 | ||
202 | ||
203 | void oprofile_shutdown(void) | |
204 | { | |
59cc185a | 205 | mutex_lock(&start_mutex); |
1474855d BN |
206 | if (oprofile_ops.sync_stop) { |
207 | int sync_ret = oprofile_ops.sync_stop(); | |
208 | switch (sync_ret) { | |
209 | case 0: | |
210 | goto post_sync; | |
211 | case 1: | |
212 | goto do_generic; | |
213 | default: | |
214 | goto post_sync; | |
215 | } | |
216 | } | |
217 | do_generic: | |
1da177e4 | 218 | sync_stop(); |
1474855d | 219 | post_sync: |
1da177e4 LT |
220 | if (oprofile_ops.shutdown) |
221 | oprofile_ops.shutdown(); | |
222 | is_setup = 0; | |
223 | free_event_buffer(); | |
224 | free_cpu_buffers(); | |
59cc185a | 225 | mutex_unlock(&start_mutex); |
1da177e4 LT |
226 | } |
227 | ||
1da177e4 LT |
228 | int oprofile_set_backtrace(unsigned long val) |
229 | { | |
230 | int err = 0; | |
231 | ||
59cc185a | 232 | mutex_lock(&start_mutex); |
1da177e4 LT |
233 | |
234 | if (oprofile_started) { | |
235 | err = -EBUSY; | |
236 | goto out; | |
237 | } | |
238 | ||
239 | if (!oprofile_ops.backtrace) { | |
240 | err = -EINVAL; | |
241 | goto out; | |
242 | } | |
243 | ||
bd2172f5 | 244 | oprofile_backtrace_depth = val; |
1da177e4 LT |
245 | |
246 | out: | |
59cc185a | 247 | mutex_unlock(&start_mutex); |
1da177e4 LT |
248 | return err; |
249 | } | |
250 | ||
251 | static int __init oprofile_init(void) | |
252 | { | |
253 | int err; | |
254 | ||
255 | err = oprofile_arch_init(&oprofile_ops); | |
256 | ||
257 | if (err < 0 || timer) { | |
258 | printk(KERN_INFO "oprofile: using timer interrupt.\n"); | |
259 | oprofile_timer_init(&oprofile_ops); | |
260 | } | |
261 | ||
262 | err = oprofilefs_register(); | |
4c50d9ea | 263 | if (err) |
1da177e4 LT |
264 | oprofile_arch_exit(); |
265 | ||
266 | return err; | |
267 | } | |
268 | ||
269 | ||
270 | static void __exit oprofile_exit(void) | |
271 | { | |
272 | oprofilefs_unregister(); | |
273 | oprofile_arch_exit(); | |
274 | } | |
275 | ||
c92960fc | 276 | |
1da177e4 LT |
277 | module_init(oprofile_init); |
278 | module_exit(oprofile_exit); | |
279 | ||
280 | module_param_named(timer, timer, int, 0644); | |
281 | MODULE_PARM_DESC(timer, "force use of timer interrupt"); | |
c92960fc | 282 | |
1da177e4 LT |
283 | MODULE_LICENSE("GPL"); |
284 | MODULE_AUTHOR("John Levon <levon@movementarian.org>"); | |
285 | MODULE_DESCRIPTION("OProfile system profiler"); |