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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> | |
41 | #include <linux/rcupdate.h> | |
42 | #include <linux/cpu.h> | |
43 | #include <linux/mutex.h> | |
44 | #include <linux/rcupreempt_trace.h> | |
45 | #include <linux/debugfs.h> | |
46 | ||
47 | static struct mutex rcupreempt_trace_mutex; | |
48 | static char *rcupreempt_trace_buf; | |
49 | #define RCUPREEMPT_TRACE_BUF_SIZE 4096 | |
50 | ||
51 | void rcupreempt_trace_move2done(struct rcupreempt_trace *trace) | |
52 | { | |
53 | trace->done_length += trace->wait_length; | |
54 | trace->done_add += trace->wait_length; | |
55 | trace->wait_length = 0; | |
56 | } | |
57 | void rcupreempt_trace_move2wait(struct rcupreempt_trace *trace) | |
58 | { | |
59 | trace->wait_length += trace->next_length; | |
60 | trace->wait_add += trace->next_length; | |
61 | trace->next_length = 0; | |
62 | } | |
63 | void rcupreempt_trace_try_flip_1(struct rcupreempt_trace *trace) | |
64 | { | |
65 | atomic_inc(&trace->rcu_try_flip_1); | |
66 | } | |
67 | void rcupreempt_trace_try_flip_e1(struct rcupreempt_trace *trace) | |
68 | { | |
69 | atomic_inc(&trace->rcu_try_flip_e1); | |
70 | } | |
71 | void rcupreempt_trace_try_flip_i1(struct rcupreempt_trace *trace) | |
72 | { | |
73 | trace->rcu_try_flip_i1++; | |
74 | } | |
75 | void rcupreempt_trace_try_flip_ie1(struct rcupreempt_trace *trace) | |
76 | { | |
77 | trace->rcu_try_flip_ie1++; | |
78 | } | |
79 | void rcupreempt_trace_try_flip_g1(struct rcupreempt_trace *trace) | |
80 | { | |
81 | trace->rcu_try_flip_g1++; | |
82 | } | |
83 | void rcupreempt_trace_try_flip_a1(struct rcupreempt_trace *trace) | |
84 | { | |
85 | trace->rcu_try_flip_a1++; | |
86 | } | |
87 | void rcupreempt_trace_try_flip_ae1(struct rcupreempt_trace *trace) | |
88 | { | |
89 | trace->rcu_try_flip_ae1++; | |
90 | } | |
91 | void rcupreempt_trace_try_flip_a2(struct rcupreempt_trace *trace) | |
92 | { | |
93 | trace->rcu_try_flip_a2++; | |
94 | } | |
95 | void rcupreempt_trace_try_flip_z1(struct rcupreempt_trace *trace) | |
96 | { | |
97 | trace->rcu_try_flip_z1++; | |
98 | } | |
99 | void rcupreempt_trace_try_flip_ze1(struct rcupreempt_trace *trace) | |
100 | { | |
101 | trace->rcu_try_flip_ze1++; | |
102 | } | |
103 | void rcupreempt_trace_try_flip_z2(struct rcupreempt_trace *trace) | |
104 | { | |
105 | trace->rcu_try_flip_z2++; | |
106 | } | |
107 | void rcupreempt_trace_try_flip_m1(struct rcupreempt_trace *trace) | |
108 | { | |
109 | trace->rcu_try_flip_m1++; | |
110 | } | |
111 | void rcupreempt_trace_try_flip_me1(struct rcupreempt_trace *trace) | |
112 | { | |
113 | trace->rcu_try_flip_me1++; | |
114 | } | |
115 | void rcupreempt_trace_try_flip_m2(struct rcupreempt_trace *trace) | |
116 | { | |
117 | trace->rcu_try_flip_m2++; | |
118 | } | |
119 | void rcupreempt_trace_check_callbacks(struct rcupreempt_trace *trace) | |
120 | { | |
121 | trace->rcu_check_callbacks++; | |
122 | } | |
123 | void rcupreempt_trace_done_remove(struct rcupreempt_trace *trace) | |
124 | { | |
125 | trace->done_remove += trace->done_length; | |
126 | trace->done_length = 0; | |
127 | } | |
128 | void rcupreempt_trace_invoke(struct rcupreempt_trace *trace) | |
129 | { | |
130 | atomic_inc(&trace->done_invoked); | |
131 | } | |
132 | void rcupreempt_trace_next_add(struct rcupreempt_trace *trace) | |
133 | { | |
134 | trace->next_add++; | |
135 | trace->next_length++; | |
136 | } | |
137 | ||
138 | static void rcupreempt_trace_sum(struct rcupreempt_trace *sp) | |
139 | { | |
140 | struct rcupreempt_trace *cp; | |
141 | int cpu; | |
142 | ||
143 | memset(sp, 0, sizeof(*sp)); | |
144 | for_each_possible_cpu(cpu) { | |
145 | cp = rcupreempt_trace_cpu(cpu); | |
146 | sp->next_length += cp->next_length; | |
147 | sp->next_add += cp->next_add; | |
148 | sp->wait_length += cp->wait_length; | |
149 | sp->wait_add += cp->wait_add; | |
150 | sp->done_length += cp->done_length; | |
151 | sp->done_add += cp->done_add; | |
152 | sp->done_remove += cp->done_remove; | |
153 | atomic_set(&sp->done_invoked, atomic_read(&cp->done_invoked)); | |
154 | sp->rcu_check_callbacks += cp->rcu_check_callbacks; | |
155 | atomic_set(&sp->rcu_try_flip_1, | |
156 | atomic_read(&cp->rcu_try_flip_1)); | |
157 | atomic_set(&sp->rcu_try_flip_e1, | |
158 | atomic_read(&cp->rcu_try_flip_e1)); | |
159 | sp->rcu_try_flip_i1 += cp->rcu_try_flip_i1; | |
160 | sp->rcu_try_flip_ie1 += cp->rcu_try_flip_ie1; | |
161 | sp->rcu_try_flip_g1 += cp->rcu_try_flip_g1; | |
162 | sp->rcu_try_flip_a1 += cp->rcu_try_flip_a1; | |
163 | sp->rcu_try_flip_ae1 += cp->rcu_try_flip_ae1; | |
164 | sp->rcu_try_flip_a2 += cp->rcu_try_flip_a2; | |
165 | sp->rcu_try_flip_z1 += cp->rcu_try_flip_z1; | |
166 | sp->rcu_try_flip_ze1 += cp->rcu_try_flip_ze1; | |
167 | sp->rcu_try_flip_z2 += cp->rcu_try_flip_z2; | |
168 | sp->rcu_try_flip_m1 += cp->rcu_try_flip_m1; | |
169 | sp->rcu_try_flip_me1 += cp->rcu_try_flip_me1; | |
170 | sp->rcu_try_flip_m2 += cp->rcu_try_flip_m2; | |
171 | } | |
172 | } | |
173 | ||
174 | static ssize_t rcustats_read(struct file *filp, char __user *buffer, | |
175 | size_t count, loff_t *ppos) | |
176 | { | |
177 | struct rcupreempt_trace trace; | |
178 | ssize_t bcount; | |
179 | int cnt = 0; | |
180 | ||
181 | rcupreempt_trace_sum(&trace); | |
182 | mutex_lock(&rcupreempt_trace_mutex); | |
183 | snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, | |
184 | "ggp=%ld rcc=%ld\n", | |
185 | rcu_batches_completed(), | |
186 | trace.rcu_check_callbacks); | |
187 | snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE - cnt, | |
188 | "na=%ld nl=%ld wa=%ld wl=%ld da=%ld dl=%ld dr=%ld di=%d\n" | |
189 | "1=%d e1=%d i1=%ld ie1=%ld g1=%ld a1=%ld ae1=%ld a2=%ld\n" | |
190 | "z1=%ld ze1=%ld z2=%ld m1=%ld me1=%ld m2=%ld\n", | |
191 | ||
192 | trace.next_add, trace.next_length, | |
193 | trace.wait_add, trace.wait_length, | |
194 | trace.done_add, trace.done_length, | |
195 | trace.done_remove, atomic_read(&trace.done_invoked), | |
196 | atomic_read(&trace.rcu_try_flip_1), | |
197 | atomic_read(&trace.rcu_try_flip_e1), | |
198 | trace.rcu_try_flip_i1, trace.rcu_try_flip_ie1, | |
199 | trace.rcu_try_flip_g1, | |
200 | trace.rcu_try_flip_a1, trace.rcu_try_flip_ae1, | |
201 | trace.rcu_try_flip_a2, | |
202 | trace.rcu_try_flip_z1, trace.rcu_try_flip_ze1, | |
203 | trace.rcu_try_flip_z2, | |
204 | trace.rcu_try_flip_m1, trace.rcu_try_flip_me1, | |
205 | trace.rcu_try_flip_m2); | |
206 | bcount = simple_read_from_buffer(buffer, count, ppos, | |
207 | rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); | |
208 | mutex_unlock(&rcupreempt_trace_mutex); | |
209 | return bcount; | |
210 | } | |
211 | ||
212 | static ssize_t rcugp_read(struct file *filp, char __user *buffer, | |
213 | size_t count, loff_t *ppos) | |
214 | { | |
215 | long oldgp = rcu_batches_completed(); | |
216 | ssize_t bcount; | |
217 | ||
218 | mutex_lock(&rcupreempt_trace_mutex); | |
219 | synchronize_rcu(); | |
220 | snprintf(rcupreempt_trace_buf, RCUPREEMPT_TRACE_BUF_SIZE, | |
221 | "oldggp=%ld newggp=%ld\n", oldgp, rcu_batches_completed()); | |
222 | bcount = simple_read_from_buffer(buffer, count, ppos, | |
223 | rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); | |
224 | mutex_unlock(&rcupreempt_trace_mutex); | |
225 | return bcount; | |
226 | } | |
227 | ||
228 | static ssize_t rcuctrs_read(struct file *filp, char __user *buffer, | |
229 | size_t count, loff_t *ppos) | |
230 | { | |
231 | int cnt = 0; | |
232 | int cpu; | |
233 | int f = rcu_batches_completed() & 0x1; | |
234 | ssize_t bcount; | |
235 | ||
236 | mutex_lock(&rcupreempt_trace_mutex); | |
237 | ||
238 | cnt += snprintf(&rcupreempt_trace_buf[cnt], RCUPREEMPT_TRACE_BUF_SIZE, | |
239 | "CPU last cur F M\n"); | |
240 | for_each_online_cpu(cpu) { | |
241 | long *flipctr = rcupreempt_flipctr(cpu); | |
242 | cnt += snprintf(&rcupreempt_trace_buf[cnt], | |
243 | RCUPREEMPT_TRACE_BUF_SIZE - cnt, | |
244 | "%3d %4ld %3ld %d %d\n", | |
245 | cpu, | |
246 | flipctr[!f], | |
247 | flipctr[f], | |
248 | rcupreempt_flip_flag(cpu), | |
249 | rcupreempt_mb_flag(cpu)); | |
250 | } | |
251 | cnt += snprintf(&rcupreempt_trace_buf[cnt], | |
252 | RCUPREEMPT_TRACE_BUF_SIZE - cnt, | |
253 | "ggp = %ld, state = %s\n", | |
254 | rcu_batches_completed(), | |
255 | rcupreempt_try_flip_state_name()); | |
256 | cnt += snprintf(&rcupreempt_trace_buf[cnt], | |
257 | RCUPREEMPT_TRACE_BUF_SIZE - cnt, | |
258 | "\n"); | |
259 | bcount = simple_read_from_buffer(buffer, count, ppos, | |
260 | rcupreempt_trace_buf, strlen(rcupreempt_trace_buf)); | |
261 | mutex_unlock(&rcupreempt_trace_mutex); | |
262 | return bcount; | |
263 | } | |
264 | ||
265 | static struct file_operations rcustats_fops = { | |
266 | .owner = THIS_MODULE, | |
267 | .read = rcustats_read, | |
268 | }; | |
269 | ||
270 | static struct file_operations rcugp_fops = { | |
271 | .owner = THIS_MODULE, | |
272 | .read = rcugp_read, | |
273 | }; | |
274 | ||
275 | static struct file_operations rcuctrs_fops = { | |
276 | .owner = THIS_MODULE, | |
277 | .read = rcuctrs_read, | |
278 | }; | |
279 | ||
280 | static struct dentry *rcudir, *statdir, *ctrsdir, *gpdir; | |
281 | static int rcupreempt_debugfs_init(void) | |
282 | { | |
283 | rcudir = debugfs_create_dir("rcu", NULL); | |
284 | if (!rcudir) | |
285 | goto out; | |
286 | statdir = debugfs_create_file("rcustats", 0444, rcudir, | |
287 | NULL, &rcustats_fops); | |
288 | if (!statdir) | |
289 | goto free_out; | |
290 | ||
291 | gpdir = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops); | |
292 | if (!gpdir) | |
293 | goto free_out; | |
294 | ||
295 | ctrsdir = debugfs_create_file("rcuctrs", 0444, rcudir, | |
296 | NULL, &rcuctrs_fops); | |
297 | if (!ctrsdir) | |
298 | goto free_out; | |
299 | return 0; | |
300 | free_out: | |
301 | if (statdir) | |
302 | debugfs_remove(statdir); | |
303 | if (gpdir) | |
304 | debugfs_remove(gpdir); | |
305 | debugfs_remove(rcudir); | |
306 | out: | |
307 | return 1; | |
308 | } | |
309 | ||
310 | static int __init rcupreempt_trace_init(void) | |
311 | { | |
312 | mutex_init(&rcupreempt_trace_mutex); | |
313 | rcupreempt_trace_buf = kmalloc(RCUPREEMPT_TRACE_BUF_SIZE, GFP_KERNEL); | |
314 | if (!rcupreempt_trace_buf) | |
315 | return 1; | |
316 | return rcupreempt_debugfs_init(); | |
317 | } | |
318 | ||
319 | static void __exit rcupreempt_trace_cleanup(void) | |
320 | { | |
321 | debugfs_remove(statdir); | |
322 | debugfs_remove(gpdir); | |
323 | debugfs_remove(ctrsdir); | |
324 | debugfs_remove(rcudir); | |
325 | kfree(rcupreempt_trace_buf); | |
326 | } | |
327 | ||
328 | ||
329 | module_init(rcupreempt_trace_init); | |
330 | module_exit(rcupreempt_trace_cleanup); |