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e260be67 PM |
1 | /* |
2 | * Read-Copy Update tracing for realtime implementation | |
3 | * | |
4 | * This program is free software; you can redistribute it and/or modify | |
5 | * it under the terms of the GNU General Public License as published by | |
6 | * the Free Software Foundation; either version 2 of the License, or | |
7 | * (at your option) any later version. | |
8 | * | |
9 | * This program is distributed in the hope that it will be useful, | |
10 | * but WITHOUT ANY WARRANTY; without even the implied warranty of | |
11 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the | |
12 | * GNU General Public License for more details. | |
13 | * | |
14 | * You should have received a copy of the GNU General Public License | |
15 | * along with this program; if not, write to the Free Software | |
16 | * Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. | |
17 | * | |
18 | * Copyright IBM Corporation, 2006 | |
19 | * | |
20 | * Papers: http://www.rdrop.com/users/paulmck/RCU | |
21 | * | |
22 | * For detailed explanation of Read-Copy Update mechanism see - | |
23 | * Documentation/RCU/ *.txt | |
24 | * | |
25 | */ | |
26 | #include <linux/types.h> | |
27 | #include <linux/kernel.h> | |
28 | #include <linux/init.h> | |
29 | #include <linux/spinlock.h> | |
30 | #include <linux/smp.h> | |
31 | #include <linux/rcupdate.h> | |
32 | #include <linux/interrupt.h> | |
33 | #include <linux/sched.h> | |
34 | #include <asm/atomic.h> | |
35 | #include <linux/bitops.h> | |
36 | #include <linux/module.h> | |
37 | #include <linux/completion.h> | |
38 | #include <linux/moduleparam.h> | |
39 | #include <linux/percpu.h> | |
40 | #include <linux/notifier.h> | |
e260be67 PM |
41 | #include <linux/cpu.h> |
42 | #include <linux/mutex.h> | |
43 | #include <linux/rcupreempt_trace.h> | |
44 | #include <linux/debugfs.h> | |
45 | ||
46 | static struct mutex rcupreempt_trace_mutex; | |
47 | static char *rcupreempt_trace_buf; | |
48 | #define RCUPREEMPT_TRACE_BUF_SIZE 4096 | |
49 | ||
50 | void rcupreempt_trace_move2done(struct rcupreempt_trace *trace) | |
51 | { | |
52 | trace->done_length += trace->wait_length; | |
53 | trace->done_add += trace->wait_length; | |
54 | trace->wait_length = 0; | |
55 | } | |
56 | void rcupreempt_trace_move2wait(struct rcupreempt_trace *trace) | |
57 | { | |
58 | trace->wait_length += trace->next_length; | |
59 | trace->wait_add += trace->next_length; | |
60 | trace->next_length = 0; | |
61 | } | |
62 | void rcupreempt_trace_try_flip_1(struct rcupreempt_trace *trace) | |
63 | { | |
64 | atomic_inc(&trace->rcu_try_flip_1); | |
65 | } | |
66 | void rcupreempt_trace_try_flip_e1(struct rcupreempt_trace *trace) | |
67 | { | |
68 | atomic_inc(&trace->rcu_try_flip_e1); | |
69 | } | |
70 | void rcupreempt_trace_try_flip_i1(struct rcupreempt_trace *trace) | |
71 | { | |
72 | trace->rcu_try_flip_i1++; | |
73 | } | |
74 | void rcupreempt_trace_try_flip_ie1(struct rcupreempt_trace *trace) | |
75 | { | |
76 | trace->rcu_try_flip_ie1++; | |
77 | } | |
78 | void rcupreempt_trace_try_flip_g1(struct rcupreempt_trace *trace) | |
79 | { | |
80 | trace->rcu_try_flip_g1++; | |
81 | } | |
82 | void rcupreempt_trace_try_flip_a1(struct rcupreempt_trace *trace) | |
83 | { | |
84 | trace->rcu_try_flip_a1++; | |
85 | } | |
86 | void rcupreempt_trace_try_flip_ae1(struct rcupreempt_trace *trace) | |
87 | { | |
88 | trace->rcu_try_flip_ae1++; | |
89 | } | |
90 | void rcupreempt_trace_try_flip_a2(struct rcupreempt_trace *trace) | |
91 | { | |
92 | trace->rcu_try_flip_a2++; | |
93 | } | |
94 | void rcupreempt_trace_try_flip_z1(struct rcupreempt_trace *trace) | |
95 | { | |
96 | trace->rcu_try_flip_z1++; | |
97 | } | |
98 | void rcupreempt_trace_try_flip_ze1(struct rcupreempt_trace *trace) | |
99 | { | |
100 | trace->rcu_try_flip_ze1++; | |
101 | } | |
102 | void rcupreempt_trace_try_flip_z2(struct rcupreempt_trace *trace) | |
103 | { | |
104 | trace->rcu_try_flip_z2++; | |
105 | } | |
106 | void rcupreempt_trace_try_flip_m1(struct rcupreempt_trace *trace) | |
107 | { | |
108 | trace->rcu_try_flip_m1++; | |
109 | } | |
110 | void rcupreempt_trace_try_flip_me1(struct rcupreempt_trace *trace) | |
111 | { | |
112 | trace->rcu_try_flip_me1++; | |
113 | } | |
114 | void rcupreempt_trace_try_flip_m2(struct rcupreempt_trace *trace) | |
115 | { | |
116 | trace->rcu_try_flip_m2++; | |
117 | } | |
118 | void rcupreempt_trace_check_callbacks(struct rcupreempt_trace *trace) | |
119 | { | |
120 | trace->rcu_check_callbacks++; | |
121 | } | |
122 | void rcupreempt_trace_done_remove(struct rcupreempt_trace *trace) | |
123 | { | |
124 | trace->done_remove += trace->done_length; | |
125 | trace->done_length = 0; | |
126 | } | |
127 | void rcupreempt_trace_invoke(struct rcupreempt_trace *trace) | |
128 | { | |
129 | atomic_inc(&trace->done_invoked); | |
130 | } | |
131 | void rcupreempt_trace_next_add(struct rcupreempt_trace *trace) | |
132 | { | |
133 | trace->next_add++; | |
134 | trace->next_length++; | |
135 | } | |
136 | ||
137 | static void rcupreempt_trace_sum(struct rcupreempt_trace *sp) | |
138 | { | |
139 | struct rcupreempt_trace *cp; | |
140 | int cpu; | |
141 | ||
142 | memset(sp, 0, sizeof(*sp)); | |
143 | for_each_possible_cpu(cpu) { | |
144 | cp = rcupreempt_trace_cpu(cpu); | |
145 | sp->next_length += cp->next_length; | |
146 | sp->next_add += cp->next_add; | |
147 | sp->wait_length += cp->wait_length; | |
148 | sp->wait_add += cp->wait_add; | |
149 | sp->done_length += cp->done_length; | |
150 | sp->done_add += cp->done_add; | |
151 | sp->done_remove += cp->done_remove; | |
64db4cff | 152 | atomic_add(atomic_read(&cp->done_invoked), &sp->done_invoked); |
e260be67 | 153 | sp->rcu_check_callbacks += cp->rcu_check_callbacks; |
64db4cff PM |
154 | atomic_add(atomic_read(&cp->rcu_try_flip_1), |
155 | &sp->rcu_try_flip_1); | |
156 | atomic_add(atomic_read(&cp->rcu_try_flip_e1), | |
157 | &sp->rcu_try_flip_e1); | |
e260be67 PM |
158 | sp->rcu_try_flip_i1 += cp->rcu_try_flip_i1; |
159 | sp->rcu_try_flip_ie1 += cp->rcu_try_flip_ie1; | |
160 | sp->rcu_try_flip_g1 += cp->rcu_try_flip_g1; | |
161 | sp->rcu_try_flip_a1 += cp->rcu_try_flip_a1; | |
162 | sp->rcu_try_flip_ae1 += cp->rcu_try_flip_ae1; | |
163 | sp->rcu_try_flip_a2 += cp->rcu_try_flip_a2; | |
164 | sp->rcu_try_flip_z1 += cp->rcu_try_flip_z1; | |
165 | sp->rcu_try_flip_ze1 += cp->rcu_try_flip_ze1; | |
166 | sp->rcu_try_flip_z2 += cp->rcu_try_flip_z2; | |
167 | sp->rcu_try_flip_m1 += cp->rcu_try_flip_m1; | |
168 | sp->rcu_try_flip_me1 += cp->rcu_try_flip_me1; | |
169 | sp->rcu_try_flip_m2 += cp->rcu_try_flip_m2; | |
170 | } | |
171 | } | |
172 | ||
173 | static ssize_t rcustats_read(struct file *filp, char __user *buffer, | |
174 | size_t count, loff_t *ppos) | |
175 | { | |
176 | struct rcupreempt_trace trace; | |
177 | ssize_t bcount; | |
178 | int cnt = 0; | |
179 | ||
180 | rcupreempt_trace_sum(&trace); | |
181 | mutex_lock(&rcupreempt_trace_mutex); | |
182 | snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, | |
183 | "ggp=%ld rcc=%ld\n", | |
184 | rcu_batches_completed(), | |
185 | trace.rcu_check_callbacks); | |
186 | snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, | |
187 | "na=%ld nl=%ld wa=%ld wl=%ld da=%ld dl=%ld dr=%ld di=%d\n" | |
188 | "1=%d e1=%d i1=%ld ie1=%ld g1=%ld a1=%ld ae1=%ld a2=%ld\n" | |
189 | "z1=%ld ze1=%ld z2=%ld m1=%ld me1=%ld m2=%ld\n", | |
190 | ||
191 | trace.next_add, trace.next_length, | |
192 | trace.wait_add, trace.wait_length, | |
193 | trace.done_add, trace.done_length, | |
194 | trace.done_remove, atomic_read(&trace.done_invoked), | |
195 | atomic_read(&trace.rcu_try_flip_1), | |
196 | atomic_read(&trace.rcu_try_flip_e1), | |
197 | trace.rcu_try_flip_i1, trace.rcu_try_flip_ie1, | |
198 | trace.rcu_try_flip_g1, | |
199 | trace.rcu_try_flip_a1, trace.rcu_try_flip_ae1, | |
200 | trace.rcu_try_flip_a2, | |
201 | trace.rcu_try_flip_z1, trace.rcu_try_flip_ze1, | |
202 | trace.rcu_try_flip_z2, | |
203 | trace.rcu_try_flip_m1, trace.rcu_try_flip_me1, | |
204 | trace.rcu_try_flip_m2); | |
205 | bcount = simple_read_from_buffer(buffer, count, ppos, | |
206 | rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); | |
207 | mutex_unlock(&rcupreempt_trace_mutex); | |
208 | return bcount; | |
209 | } | |
210 | ||
211 | static ssize_t rcugp_read(struct file *filp, char __user *buffer, | |
212 | size_t count, loff_t *ppos) | |
213 | { | |
214 | long oldgp = rcu_batches_completed(); | |
215 | ssize_t bcount; | |
216 | ||
217 | mutex_lock(&rcupreempt_trace_mutex); | |
218 | synchronize_rcu(); | |
219 | snprintf(rcupreempt_trace_buf, RCUPREEMPT_TRACE_BUF_SIZE, | |
220 | "oldggp=%ld newggp=%ld\n", oldgp, rcu_batches_completed()); | |
221 | bcount = simple_read_from_buffer(buffer, count, ppos, | |
222 | rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); | |
223 | mutex_unlock(&rcupreempt_trace_mutex); | |
224 | return bcount; | |
225 | } | |
226 | ||
227 | static ssize_t rcuctrs_read(struct file *filp, char __user *buffer, | |
228 | size_t count, loff_t *ppos) | |
229 | { | |
230 | int cnt = 0; | |
231 | int cpu; | |
232 | int f = rcu_batches_completed() & 0x1; | |
233 | ssize_t bcount; | |
234 | ||
235 | mutex_lock(&rcupreempt_trace_mutex); | |
236 | ||
237 | cnt += snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE, | |
238 | "CPU last cur F M\n"); | |
239 | for_each_online_cpu(cpu) { | |
240 | long *flipctr = rcupreempt_flipctr(cpu); | |
241 | cnt += snprintf(&rcupreempt_trace_buf[cnt], | |
242 | RCUPREEMPT_TRACE_BUF_SIZE - cnt, | |
243 | "%3d %4ld %3ld %d %d\n", | |
244 | cpu, | |
245 | flipctr[!f], | |
246 | flipctr[f], | |
247 | rcupreempt_flip_flag(cpu), | |
248 | rcupreempt_mb_flag(cpu)); | |
249 | } | |
250 | cnt += snprintf(&rcupreempt_trace_buf[cnt], | |
251 | RCUPREEMPT_TRACE_BUF_SIZE - cnt, | |
252 | "ggp = %ld, state = %s\n", | |
253 | rcu_batches_completed(), | |
254 | rcupreempt_try_flip_state_name()); | |
255 | cnt += snprintf(&rcupreempt_trace_buf[cnt], | |
256 | RCUPREEMPT_TRACE_BUF_SIZE - cnt, | |
257 | "\n"); | |
258 | bcount = simple_read_from_buffer(buffer, count, ppos, | |
259 | rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); | |
260 | mutex_unlock(&rcupreempt_trace_mutex); | |
261 | return bcount; | |
262 | } | |
263 | ||
264 | static struct file_operations rcustats_fops = { | |
265 | .owner = THIS_MODULE, | |
266 | .read = rcustats_read, | |
267 | }; | |
268 | ||
269 | static struct file_operations rcugp_fops = { | |
270 | .owner = THIS_MODULE, | |
271 | .read = rcugp_read, | |
272 | }; | |
273 | ||
274 | static struct file_operations rcuctrs_fops = { | |
275 | .owner = THIS_MODULE, | |
276 | .read = rcuctrs_read, | |
277 | }; | |
278 | ||
279 | static struct dentry *rcudir, *statdir, *ctrsdir, *gpdir; | |
280 | static int rcupreempt_debugfs_init(void) | |
281 | { | |
282 | rcudir = debugfs_create_dir("rcu", NULL); | |
283 | if (!rcudir) | |
284 | goto out; | |
285 | statdir = debugfs_create_file("rcustats", 0444, rcudir, | |
286 | NULL, &rcustats_fops); | |
287 | if (!statdir) | |
288 | goto free_out; | |
289 | ||
290 | gpdir = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops); | |
291 | if (!gpdir) | |
292 | goto free_out; | |
293 | ||
294 | ctrsdir = debugfs_create_file("rcuctrs", 0444, rcudir, | |
295 | NULL, &rcuctrs_fops); | |
296 | if (!ctrsdir) | |
297 | goto free_out; | |
298 | return 0; | |
299 | free_out: | |
300 | if (statdir) | |
301 | debugfs_remove(statdir); | |
302 | if (gpdir) | |
303 | debugfs_remove(gpdir); | |
304 | debugfs_remove(rcudir); | |
305 | out: | |
306 | return 1; | |
307 | } | |
308 | ||
309 | static int __init rcupreempt_trace_init(void) | |
310 | { | |
5802294f SR |
311 | int ret; |
312 | ||
e260be67 PM |
313 | mutex_init(&rcupreempt_trace_mutex); |
314 | rcupreempt_trace_buf = kmalloc(RCUPREEMPT_TRACE_BUF_SIZE, GFP_KERNEL); | |
315 | if (!rcupreempt_trace_buf) | |
316 | return 1; | |
5802294f SR |
317 | ret = rcupreempt_debugfs_init(); |
318 | if (ret) | |
319 | kfree(rcupreempt_trace_buf); | |
320 | return ret; | |
e260be67 PM |
321 | } |
322 | ||
323 | static void __exit rcupreempt_trace_cleanup(void) | |
324 | { | |
325 | debugfs_remove(statdir); | |
326 | debugfs_remove(gpdir); | |
327 | debugfs_remove(ctrsdir); | |
328 | debugfs_remove(rcudir); | |
329 | kfree(rcupreempt_trace_buf); | |
330 | } | |
331 | ||
332 | ||
333 | module_init(rcupreempt_trace_init); | |
334 | module_exit(rcupreempt_trace_cleanup); |