Commit | Line | Data |
---|---|---|
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> | |
59cc185a | 15 | #include <asm/mutex.h> |
1da177e4 LT |
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; | |
59cc185a | 28 | static DEFINE_MUTEX(start_mutex); |
1da177e4 LT |
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 | ||
59cc185a | 40 | mutex_lock(&start_mutex); |
1da177e4 LT |
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 | */ | |
1474855d BN |
56 | if (oprofile_ops.sync_start) { |
57 | int sync_ret = oprofile_ops.sync_start(); | |
58 | switch (sync_ret) { | |
59 | case 0: | |
60 | goto post_sync; | |
61 | case 1: | |
62 | goto do_generic; | |
63 | case -1: | |
64 | goto out3; | |
65 | default: | |
66 | goto out3; | |
67 | } | |
68 | } | |
69 | do_generic: | |
1da177e4 LT |
70 | if ((err = sync_start())) |
71 | goto out3; | |
72 | ||
1474855d | 73 | post_sync: |
1da177e4 | 74 | is_setup = 1; |
59cc185a | 75 | mutex_unlock(&start_mutex); |
1da177e4 LT |
76 | return 0; |
77 | ||
78 | out3: | |
79 | if (oprofile_ops.shutdown) | |
80 | oprofile_ops.shutdown(); | |
81 | out2: | |
82 | free_event_buffer(); | |
83 | out1: | |
84 | free_cpu_buffers(); | |
85 | out: | |
59cc185a | 86 | mutex_unlock(&start_mutex); |
1da177e4 LT |
87 | return err; |
88 | } | |
89 | ||
90 | ||
91 | /* Actually start profiling (echo 1>/dev/oprofile/enable) */ | |
92 | int oprofile_start(void) | |
93 | { | |
94 | int err = -EINVAL; | |
95 | ||
59cc185a | 96 | mutex_lock(&start_mutex); |
1da177e4 LT |
97 | |
98 | if (!is_setup) | |
99 | goto out; | |
100 | ||
101 | err = 0; | |
102 | ||
103 | if (oprofile_started) | |
104 | goto out; | |
105 | ||
106 | oprofile_reset_stats(); | |
107 | ||
108 | if ((err = oprofile_ops.start())) | |
109 | goto out; | |
110 | ||
111 | oprofile_started = 1; | |
112 | out: | |
59cc185a | 113 | mutex_unlock(&start_mutex); |
1da177e4 LT |
114 | return err; |
115 | } | |
116 | ||
117 | ||
118 | /* echo 0>/dev/oprofile/enable */ | |
119 | void oprofile_stop(void) | |
120 | { | |
59cc185a | 121 | mutex_lock(&start_mutex); |
1da177e4 LT |
122 | if (!oprofile_started) |
123 | goto out; | |
124 | oprofile_ops.stop(); | |
125 | oprofile_started = 0; | |
126 | /* wake up the daemon to read what remains */ | |
127 | wake_up_buffer_waiter(); | |
128 | out: | |
59cc185a | 129 | mutex_unlock(&start_mutex); |
1da177e4 LT |
130 | } |
131 | ||
132 | ||
133 | void oprofile_shutdown(void) | |
134 | { | |
59cc185a | 135 | mutex_lock(&start_mutex); |
1474855d BN |
136 | if (oprofile_ops.sync_stop) { |
137 | int sync_ret = oprofile_ops.sync_stop(); | |
138 | switch (sync_ret) { | |
139 | case 0: | |
140 | goto post_sync; | |
141 | case 1: | |
142 | goto do_generic; | |
143 | default: | |
144 | goto post_sync; | |
145 | } | |
146 | } | |
147 | do_generic: | |
1da177e4 | 148 | sync_stop(); |
1474855d | 149 | post_sync: |
1da177e4 LT |
150 | if (oprofile_ops.shutdown) |
151 | oprofile_ops.shutdown(); | |
152 | is_setup = 0; | |
153 | free_event_buffer(); | |
154 | free_cpu_buffers(); | |
59cc185a | 155 | mutex_unlock(&start_mutex); |
1da177e4 LT |
156 | } |
157 | ||
158 | ||
159 | int oprofile_set_backtrace(unsigned long val) | |
160 | { | |
161 | int err = 0; | |
162 | ||
59cc185a | 163 | mutex_lock(&start_mutex); |
1da177e4 LT |
164 | |
165 | if (oprofile_started) { | |
166 | err = -EBUSY; | |
167 | goto out; | |
168 | } | |
169 | ||
170 | if (!oprofile_ops.backtrace) { | |
171 | err = -EINVAL; | |
172 | goto out; | |
173 | } | |
174 | ||
175 | backtrace_depth = val; | |
176 | ||
177 | out: | |
59cc185a | 178 | mutex_unlock(&start_mutex); |
1da177e4 LT |
179 | return err; |
180 | } | |
181 | ||
182 | static int __init oprofile_init(void) | |
183 | { | |
184 | int err; | |
185 | ||
186 | err = oprofile_arch_init(&oprofile_ops); | |
187 | ||
188 | if (err < 0 || timer) { | |
189 | printk(KERN_INFO "oprofile: using timer interrupt.\n"); | |
190 | oprofile_timer_init(&oprofile_ops); | |
191 | } | |
192 | ||
193 | err = oprofilefs_register(); | |
194 | if (err) | |
195 | oprofile_arch_exit(); | |
196 | ||
197 | return err; | |
198 | } | |
199 | ||
200 | ||
201 | static void __exit oprofile_exit(void) | |
202 | { | |
203 | oprofilefs_unregister(); | |
204 | oprofile_arch_exit(); | |
205 | } | |
206 | ||
207 | ||
208 | module_init(oprofile_init); | |
209 | module_exit(oprofile_exit); | |
210 | ||
211 | module_param_named(timer, timer, int, 0644); | |
212 | MODULE_PARM_DESC(timer, "force use of timer interrupt"); | |
213 | ||
214 | MODULE_LICENSE("GPL"); | |
215 | MODULE_AUTHOR("John Levon <levon@movementarian.org>"); | |
216 | MODULE_DESCRIPTION("OProfile system profiler"); |