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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> | |
1a960b40 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" | |
1a960b40 JY |
24 | |
25 | static unsigned long is_setup; | |
26 | static void switch_worker(struct work_struct *work); | |
27 | static DECLARE_DELAYED_WORK(switch_work, switch_worker); | |
28 | static DEFINE_MUTEX(start_mutex); | |
1da177e4 LT |
29 | |
30 | struct oprofile_operations oprofile_ops; | |
31 | ||
1a960b40 | 32 | unsigned long timeout_jiffies; |
1da177e4 LT |
33 | unsigned long oprofile_started; |
34 | unsigned long backtrace_depth; | |
1a960b40 | 35 | /* Multiplexing defaults at 1 msec*/ |
1da177e4 LT |
36 | |
37 | /* timer | |
38 | 0 - use performance monitoring hardware if available | |
39 | 1 - use the timer int mechanism regardless | |
40 | */ | |
41 | static int timer = 0; | |
42 | ||
43 | int oprofile_setup(void) | |
44 | { | |
45 | int err; | |
46 | ||
59cc185a | 47 | mutex_lock(&start_mutex); |
1da177e4 LT |
48 | |
49 | if ((err = alloc_cpu_buffers())) | |
50 | goto out; | |
51 | ||
52 | if ((err = alloc_event_buffer())) | |
53 | goto out1; | |
54 | ||
55 | if (oprofile_ops.setup && (err = oprofile_ops.setup())) | |
56 | goto out2; | |
57 | ||
58 | /* Note even though this starts part of the | |
59 | * profiling overhead, it's necessary to prevent | |
60 | * us missing task deaths and eventually oopsing | |
61 | * when trying to process the event buffer. | |
62 | */ | |
1474855d BN |
63 | if (oprofile_ops.sync_start) { |
64 | int sync_ret = oprofile_ops.sync_start(); | |
65 | switch (sync_ret) { | |
66 | case 0: | |
67 | goto post_sync; | |
68 | case 1: | |
69 | goto do_generic; | |
70 | case -1: | |
71 | goto out3; | |
72 | default: | |
73 | goto out3; | |
74 | } | |
75 | } | |
76 | do_generic: | |
1da177e4 LT |
77 | if ((err = sync_start())) |
78 | goto out3; | |
79 | ||
1474855d | 80 | post_sync: |
1da177e4 | 81 | is_setup = 1; |
59cc185a | 82 | mutex_unlock(&start_mutex); |
1da177e4 LT |
83 | return 0; |
84 | ||
85 | out3: | |
86 | if (oprofile_ops.shutdown) | |
87 | oprofile_ops.shutdown(); | |
88 | out2: | |
89 | free_event_buffer(); | |
90 | out1: | |
91 | free_cpu_buffers(); | |
92 | out: | |
59cc185a | 93 | mutex_unlock(&start_mutex); |
1da177e4 LT |
94 | return err; |
95 | } | |
96 | ||
1a960b40 JY |
97 | static void start_switch_worker(void) |
98 | { | |
99 | schedule_delayed_work(&switch_work, timeout_jiffies); | |
100 | } | |
101 | ||
102 | static void switch_worker(struct work_struct *work) | |
103 | { | |
104 | if (!oprofile_ops.switch_events()) | |
105 | start_switch_worker(); | |
106 | } | |
1da177e4 LT |
107 | |
108 | /* Actually start profiling (echo 1>/dev/oprofile/enable) */ | |
109 | int oprofile_start(void) | |
110 | { | |
111 | int err = -EINVAL; | |
112 | ||
59cc185a | 113 | mutex_lock(&start_mutex); |
1da177e4 LT |
114 | if (!is_setup) |
115 | goto out; | |
116 | ||
117 | err = 0; | |
118 | ||
119 | if (oprofile_started) | |
120 | goto out; | |
121 | ||
122 | oprofile_reset_stats(); | |
123 | ||
124 | if ((err = oprofile_ops.start())) | |
125 | goto out; | |
126 | ||
1a960b40 JY |
127 | if (oprofile_ops.switch_events) |
128 | start_switch_worker(); | |
129 | ||
1da177e4 LT |
130 | oprofile_started = 1; |
131 | out: | |
59cc185a | 132 | mutex_unlock(&start_mutex); |
1da177e4 LT |
133 | return err; |
134 | } | |
135 | ||
136 | ||
137 | /* echo 0>/dev/oprofile/enable */ | |
138 | void oprofile_stop(void) | |
139 | { | |
59cc185a | 140 | mutex_lock(&start_mutex); |
1da177e4 LT |
141 | if (!oprofile_started) |
142 | goto out; | |
143 | oprofile_ops.stop(); | |
144 | oprofile_started = 0; | |
1a960b40 | 145 | cancel_delayed_work_sync(&switch_work); |
1da177e4 LT |
146 | /* wake up the daemon to read what remains */ |
147 | wake_up_buffer_waiter(); | |
148 | out: | |
59cc185a | 149 | mutex_unlock(&start_mutex); |
1da177e4 LT |
150 | } |
151 | ||
152 | ||
153 | void oprofile_shutdown(void) | |
154 | { | |
59cc185a | 155 | mutex_lock(&start_mutex); |
1474855d BN |
156 | if (oprofile_ops.sync_stop) { |
157 | int sync_ret = oprofile_ops.sync_stop(); | |
158 | switch (sync_ret) { | |
159 | case 0: | |
160 | goto post_sync; | |
161 | case 1: | |
162 | goto do_generic; | |
163 | default: | |
164 | goto post_sync; | |
165 | } | |
166 | } | |
167 | do_generic: | |
1da177e4 | 168 | sync_stop(); |
1474855d | 169 | post_sync: |
1da177e4 LT |
170 | if (oprofile_ops.shutdown) |
171 | oprofile_ops.shutdown(); | |
172 | is_setup = 0; | |
173 | free_event_buffer(); | |
174 | free_cpu_buffers(); | |
59cc185a | 175 | mutex_unlock(&start_mutex); |
1da177e4 LT |
176 | } |
177 | ||
1a960b40 JY |
178 | /* User inputs in ms, converts to jiffies */ |
179 | int oprofile_set_timeout(unsigned long val_msec) | |
180 | { | |
181 | int err = 0; | |
182 | ||
183 | mutex_lock(&start_mutex); | |
184 | ||
185 | if (oprofile_started) { | |
186 | err = -EBUSY; | |
187 | goto out; | |
188 | } | |
189 | ||
190 | if (!oprofile_ops.switch_events) { | |
191 | err = -EINVAL; | |
192 | goto out; | |
193 | } | |
194 | ||
195 | timeout_jiffies = msecs_to_jiffies(val_msec); | |
196 | if (timeout_jiffies == MAX_JIFFY_OFFSET) | |
197 | timeout_jiffies = msecs_to_jiffies(1); | |
198 | ||
199 | out: | |
200 | mutex_unlock(&start_mutex); | |
201 | return err; | |
202 | ||
203 | } | |
1da177e4 LT |
204 | |
205 | int oprofile_set_backtrace(unsigned long val) | |
206 | { | |
207 | int err = 0; | |
208 | ||
59cc185a | 209 | mutex_lock(&start_mutex); |
1da177e4 LT |
210 | |
211 | if (oprofile_started) { | |
212 | err = -EBUSY; | |
213 | goto out; | |
214 | } | |
215 | ||
216 | if (!oprofile_ops.backtrace) { | |
217 | err = -EINVAL; | |
218 | goto out; | |
219 | } | |
220 | ||
221 | backtrace_depth = val; | |
222 | ||
223 | out: | |
59cc185a | 224 | mutex_unlock(&start_mutex); |
1da177e4 LT |
225 | return err; |
226 | } | |
227 | ||
1a960b40 JY |
228 | static void __init oprofile_switch_timer_init(void) |
229 | { | |
230 | timeout_jiffies = msecs_to_jiffies(1); | |
231 | } | |
232 | ||
1da177e4 LT |
233 | static int __init oprofile_init(void) |
234 | { | |
235 | int err; | |
236 | ||
1a960b40 | 237 | oprofile_switch_timer_init(); |
1da177e4 LT |
238 | err = oprofile_arch_init(&oprofile_ops); |
239 | ||
240 | if (err < 0 || timer) { | |
241 | printk(KERN_INFO "oprofile: using timer interrupt.\n"); | |
242 | oprofile_timer_init(&oprofile_ops); | |
243 | } | |
244 | ||
245 | err = oprofilefs_register(); | |
246 | if (err) | |
247 | oprofile_arch_exit(); | |
248 | ||
249 | return err; | |
250 | } | |
251 | ||
252 | ||
253 | static void __exit oprofile_exit(void) | |
254 | { | |
255 | oprofilefs_unregister(); | |
256 | oprofile_arch_exit(); | |
257 | } | |
258 | ||
259 | ||
260 | module_init(oprofile_init); | |
261 | module_exit(oprofile_exit); | |
262 | ||
263 | module_param_named(timer, timer, int, 0644); | |
264 | MODULE_PARM_DESC(timer, "force use of timer interrupt"); | |
265 | ||
266 | MODULE_LICENSE("GPL"); | |
267 | MODULE_AUTHOR("John Levon <levon@movementarian.org>"); | |
268 | MODULE_DESCRIPTION("OProfile system profiler"); |