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64db4cff PM |
1 | /* |
2 | * Read-Copy Update tracing for classic 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, 2008 | |
19 | * | |
20 | * Papers: http://www.rdrop.com/users/paulmck/RCU | |
21 | * | |
22 | * For detailed explanation of Read-Copy Update mechanism see - | |
a71fca58 | 23 | * Documentation/RCU |
64db4cff PM |
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> | |
60063497 | 34 | #include <linux/atomic.h> |
64db4cff PM |
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/cpu.h> | |
42 | #include <linux/mutex.h> | |
43 | #include <linux/debugfs.h> | |
44 | #include <linux/seq_file.h> | |
45 | ||
9f77da9f | 46 | #define RCU_TREE_NONCORE |
6258c4fb IM |
47 | #include "rcutree.h" |
48 | ||
374b928e MW |
49 | static int r_open(struct inode *inode, struct file *file, |
50 | const struct seq_operations *op) | |
51 | { | |
52 | int ret = seq_open(file, op); | |
53 | if (!ret) { | |
54 | struct seq_file *m = (struct seq_file *)file->private_data; | |
55 | m->private = inode->i_private; | |
56 | } | |
57 | return ret; | |
58 | } | |
59 | ||
60 | static void *r_start(struct seq_file *m, loff_t *pos) | |
61 | { | |
62 | struct rcu_state *rsp = (struct rcu_state *)m->private; | |
63 | *pos = cpumask_next(*pos - 1, cpu_possible_mask); | |
64 | if ((*pos) < nr_cpu_ids) | |
65 | return per_cpu_ptr(rsp->rda, *pos); | |
66 | return NULL; | |
67 | } | |
68 | ||
69 | static void *r_next(struct seq_file *m, void *v, loff_t *pos) | |
70 | { | |
71 | (*pos)++; | |
72 | return r_start(m, pos); | |
73 | } | |
74 | ||
75 | static void r_stop(struct seq_file *m, void *v) | |
76 | { | |
77 | } | |
78 | ||
d7e187c8 PM |
79 | static int show_rcubarrier(struct seq_file *m, void *unused) |
80 | { | |
c0cc962d PM |
81 | struct rcu_state *rsp; |
82 | ||
83 | for_each_rcu_flavor(rsp) | |
1331e7a1 PM |
84 | seq_printf(m, "%s: bcc: %d nbd: %lu\n", |
85 | rsp->name, | |
c0cc962d PM |
86 | atomic_read(&rsp->barrier_cpu_count), |
87 | rsp->n_barrier_done); | |
d7e187c8 PM |
88 | return 0; |
89 | } | |
90 | ||
91 | static int rcubarrier_open(struct inode *inode, struct file *file) | |
92 | { | |
93 | return single_open(file, show_rcubarrier, NULL); | |
94 | } | |
95 | ||
96 | static const struct file_operations rcubarrier_fops = { | |
97 | .owner = THIS_MODULE, | |
98 | .open = rcubarrier_open, | |
99 | .read = seq_read, | |
100 | .llseek = seq_lseek, | |
101 | .release = single_release, | |
102 | }; | |
103 | ||
a46e0899 PM |
104 | #ifdef CONFIG_RCU_BOOST |
105 | ||
d71df90e PM |
106 | static char convert_kthread_status(unsigned int kthread_status) |
107 | { | |
108 | if (kthread_status > RCU_KTHREAD_MAX) | |
109 | return '?'; | |
15ba0ba8 | 110 | return "SRWOY"[kthread_status]; |
d71df90e PM |
111 | } |
112 | ||
a46e0899 PM |
113 | #endif /* #ifdef CONFIG_RCU_BOOST */ |
114 | ||
64db4cff PM |
115 | static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp) |
116 | { | |
117 | if (!rdp->beenonline) | |
118 | return; | |
d7d6a11e | 119 | seq_printf(m, "%3d%cc=%lu g=%lu pq=%d qp=%d", |
64db4cff PM |
120 | rdp->cpu, |
121 | cpu_is_offline(rdp->cpu) ? '!' : ' ', | |
122 | rdp->completed, rdp->gpnum, | |
d7d6a11e | 123 | rdp->passed_quiesce, rdp->qs_pending); |
9b2e4f18 | 124 | seq_printf(m, " dt=%d/%llx/%d df=%lu", |
23b5c8fa | 125 | atomic_read(&rdp->dynticks->dynticks), |
64db4cff | 126 | rdp->dynticks->dynticks_nesting, |
23b5c8fa | 127 | rdp->dynticks->dynticks_nmi_nesting, |
64db4cff | 128 | rdp->dynticks_fqs); |
2036d94a | 129 | seq_printf(m, " of=%lu", rdp->offline_fqs); |
486e2593 PM |
130 | seq_printf(m, " ql=%ld/%ld qs=%c%c%c%c", |
131 | rdp->qlen_lazy, rdp->qlen, | |
0ac3d136 PM |
132 | ".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] != |
133 | rdp->nxttail[RCU_NEXT_TAIL]], | |
134 | ".R"[rdp->nxttail[RCU_WAIT_TAIL] != | |
135 | rdp->nxttail[RCU_NEXT_READY_TAIL]], | |
136 | ".W"[rdp->nxttail[RCU_DONE_TAIL] != | |
137 | rdp->nxttail[RCU_WAIT_TAIL]], | |
a46e0899 PM |
138 | ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]); |
139 | #ifdef CONFIG_RCU_BOOST | |
62ab7072 | 140 | seq_printf(m, " kt=%d/%c ktl=%x", |
d71df90e PM |
141 | per_cpu(rcu_cpu_has_work, rdp->cpu), |
142 | convert_kthread_status(per_cpu(rcu_cpu_kthread_status, | |
143 | rdp->cpu)), | |
a46e0899 PM |
144 | per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff); |
145 | #endif /* #ifdef CONFIG_RCU_BOOST */ | |
146 | seq_printf(m, " b=%ld", rdp->blimit); | |
269dcc1c PM |
147 | seq_printf(m, " ci=%lu co=%lu ca=%lu\n", |
148 | rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted); | |
64db4cff PM |
149 | } |
150 | ||
c011c41f | 151 | static int show_rcudata(struct seq_file *m, void *v) |
878eda72 MW |
152 | { |
153 | print_one_rcu_data(m, (struct rcu_data *)v); | |
154 | return 0; | |
155 | } | |
156 | ||
c011c41f | 157 | static const struct seq_operations rcudate_op = { |
878eda72 MW |
158 | .start = r_start, |
159 | .next = r_next, | |
160 | .stop = r_stop, | |
c011c41f | 161 | .show = show_rcudata, |
878eda72 MW |
162 | }; |
163 | ||
c011c41f | 164 | static int rcudata_open(struct inode *inode, struct file *file) |
878eda72 | 165 | { |
c011c41f | 166 | return r_open(inode, file, &rcudate_op); |
878eda72 MW |
167 | } |
168 | ||
c011c41f | 169 | static const struct file_operations rcudata_fops = { |
878eda72 | 170 | .owner = THIS_MODULE, |
c011c41f | 171 | .open = rcudata_open, |
878eda72 MW |
172 | .read = seq_read, |
173 | .llseek = no_llseek, | |
174 | .release = seq_release, | |
175 | }; | |
176 | ||
0ea1f2eb PM |
177 | #ifdef CONFIG_RCU_BOOST |
178 | ||
179 | static void print_one_rcu_node_boost(struct seq_file *m, struct rcu_node *rnp) | |
180 | { | |
5cf05ad7 | 181 | seq_printf(m, "%d:%d tasks=%c%c%c%c kt=%c ntb=%lu neb=%lu nnb=%lu ", |
0ea1f2eb PM |
182 | rnp->grplo, rnp->grphi, |
183 | "T."[list_empty(&rnp->blkd_tasks)], | |
184 | "N."[!rnp->gp_tasks], | |
185 | "E."[!rnp->exp_tasks], | |
186 | "B."[!rnp->boost_tasks], | |
d71df90e | 187 | convert_kthread_status(rnp->boost_kthread_status), |
0ea1f2eb | 188 | rnp->n_tasks_boosted, rnp->n_exp_boosts, |
5cf05ad7 PM |
189 | rnp->n_normal_boosts); |
190 | seq_printf(m, "j=%04x bt=%04x\n", | |
0ea1f2eb PM |
191 | (int)(jiffies & 0xffff), |
192 | (int)(rnp->boost_time & 0xffff)); | |
5cf05ad7 | 193 | seq_printf(m, " balk: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n", |
0ea1f2eb PM |
194 | rnp->n_balk_blkd_tasks, |
195 | rnp->n_balk_exp_gp_tasks, | |
196 | rnp->n_balk_boost_tasks, | |
197 | rnp->n_balk_notblocked, | |
198 | rnp->n_balk_notyet, | |
199 | rnp->n_balk_nos); | |
200 | } | |
201 | ||
202 | static int show_rcu_node_boost(struct seq_file *m, void *unused) | |
203 | { | |
204 | struct rcu_node *rnp; | |
205 | ||
206 | rcu_for_each_leaf_node(&rcu_preempt_state, rnp) | |
207 | print_one_rcu_node_boost(m, rnp); | |
208 | return 0; | |
209 | } | |
210 | ||
211 | static int rcu_node_boost_open(struct inode *inode, struct file *file) | |
212 | { | |
213 | return single_open(file, show_rcu_node_boost, NULL); | |
214 | } | |
215 | ||
216 | static const struct file_operations rcu_node_boost_fops = { | |
217 | .owner = THIS_MODULE, | |
218 | .open = rcu_node_boost_open, | |
219 | .read = seq_read, | |
220 | .llseek = seq_lseek, | |
221 | .release = single_release, | |
222 | }; | |
223 | ||
224 | /* | |
225 | * Create the rcuboost debugfs entry. Standard error return. | |
226 | */ | |
227 | static int rcu_boost_trace_create_file(struct dentry *rcudir) | |
228 | { | |
229 | return !debugfs_create_file("rcuboost", 0444, rcudir, NULL, | |
230 | &rcu_node_boost_fops); | |
231 | } | |
232 | ||
233 | #else /* #ifdef CONFIG_RCU_BOOST */ | |
234 | ||
235 | static int rcu_boost_trace_create_file(struct dentry *rcudir) | |
236 | { | |
237 | return 0; /* There cannot be an error if we didn't create it! */ | |
238 | } | |
239 | ||
240 | #endif /* #else #ifdef CONFIG_RCU_BOOST */ | |
241 | ||
64db4cff PM |
242 | static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp) |
243 | { | |
20133cfc | 244 | unsigned long gpnum; |
64db4cff PM |
245 | int level = 0; |
246 | struct rcu_node *rnp; | |
247 | ||
3397e040 | 248 | gpnum = rsp->gpnum; |
5cf05ad7 | 249 | seq_printf(m, "%s: c=%lu g=%lu s=%d jfq=%ld j=%x ", |
c0cc962d | 250 | rsp->name, rsp->completed, gpnum, rsp->fqs_state, |
64db4cff | 251 | (long)(rsp->jiffies_force_qs - jiffies), |
5cf05ad7 PM |
252 | (int)(jiffies & 0xffff)); |
253 | seq_printf(m, "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld/%ld\n", | |
64db4cff PM |
254 | rsp->n_force_qs, rsp->n_force_qs_ngp, |
255 | rsp->n_force_qs - rsp->n_force_qs_ngp, | |
b1420f1c | 256 | rsp->n_force_qs_lh, rsp->qlen_lazy, rsp->qlen); |
f885b7f2 | 257 | for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_nodes; rnp++) { |
64db4cff PM |
258 | if (rnp->level != level) { |
259 | seq_puts(m, "\n"); | |
260 | level = rnp->level; | |
261 | } | |
12f5f524 | 262 | seq_printf(m, "%lx/%lx %c%c>%c %d:%d ^%d ", |
64db4cff | 263 | rnp->qsmask, rnp->qsmaskinit, |
12f5f524 PM |
264 | ".G"[rnp->gp_tasks != NULL], |
265 | ".E"[rnp->exp_tasks != NULL], | |
266 | ".T"[!list_empty(&rnp->blkd_tasks)], | |
64db4cff PM |
267 | rnp->grplo, rnp->grphi, rnp->grpnum); |
268 | } | |
269 | seq_puts(m, "\n"); | |
270 | } | |
271 | ||
272 | static int show_rcuhier(struct seq_file *m, void *unused) | |
273 | { | |
c0cc962d PM |
274 | struct rcu_state *rsp; |
275 | ||
276 | for_each_rcu_flavor(rsp) | |
277 | print_one_rcu_state(m, rsp); | |
64db4cff PM |
278 | return 0; |
279 | } | |
280 | ||
281 | static int rcuhier_open(struct inode *inode, struct file *file) | |
282 | { | |
283 | return single_open(file, show_rcuhier, NULL); | |
284 | } | |
285 | ||
9b2619af | 286 | static const struct file_operations rcuhier_fops = { |
64db4cff PM |
287 | .owner = THIS_MODULE, |
288 | .open = rcuhier_open, | |
289 | .read = seq_read, | |
290 | .llseek = seq_lseek, | |
291 | .release = single_release, | |
292 | }; | |
293 | ||
15ba0ba8 PM |
294 | static void show_one_rcugp(struct seq_file *m, struct rcu_state *rsp) |
295 | { | |
296 | unsigned long flags; | |
297 | unsigned long completed; | |
298 | unsigned long gpnum; | |
299 | unsigned long gpage; | |
300 | unsigned long gpmax; | |
301 | struct rcu_node *rnp = &rsp->node[0]; | |
302 | ||
303 | raw_spin_lock_irqsave(&rnp->lock, flags); | |
304 | completed = rsp->completed; | |
305 | gpnum = rsp->gpnum; | |
306 | if (rsp->completed == rsp->gpnum) | |
307 | gpage = 0; | |
308 | else | |
309 | gpage = jiffies - rsp->gp_start; | |
310 | gpmax = rsp->gp_max; | |
311 | raw_spin_unlock_irqrestore(&rnp->lock, flags); | |
312 | seq_printf(m, "%s: completed=%ld gpnum=%lu age=%ld max=%ld\n", | |
313 | rsp->name, completed, gpnum, gpage, gpmax); | |
314 | } | |
315 | ||
64db4cff PM |
316 | static int show_rcugp(struct seq_file *m, void *unused) |
317 | { | |
c0cc962d PM |
318 | struct rcu_state *rsp; |
319 | ||
320 | for_each_rcu_flavor(rsp) | |
321 | show_one_rcugp(m, rsp); | |
64db4cff PM |
322 | return 0; |
323 | } | |
324 | ||
325 | static int rcugp_open(struct inode *inode, struct file *file) | |
326 | { | |
327 | return single_open(file, show_rcugp, NULL); | |
328 | } | |
329 | ||
9b2619af | 330 | static const struct file_operations rcugp_fops = { |
64db4cff PM |
331 | .owner = THIS_MODULE, |
332 | .open = rcugp_open, | |
333 | .read = seq_read, | |
334 | .llseek = seq_lseek, | |
335 | .release = single_release, | |
336 | }; | |
337 | ||
7ba5c840 PM |
338 | static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp) |
339 | { | |
51d0f16d MW |
340 | if (!rdp->beenonline) |
341 | return; | |
5cf05ad7 | 342 | seq_printf(m, "%3d%cnp=%ld ", |
7ba5c840 PM |
343 | rdp->cpu, |
344 | cpu_is_offline(rdp->cpu) ? '!' : ' ', | |
5cf05ad7 PM |
345 | rdp->n_rcu_pending); |
346 | seq_printf(m, "qsp=%ld rpq=%ld cbr=%ld cng=%ld ", | |
7ba5c840 | 347 | rdp->n_rp_qs_pending, |
d21670ac | 348 | rdp->n_rp_report_qs, |
7ba5c840 | 349 | rdp->n_rp_cb_ready, |
5cf05ad7 | 350 | rdp->n_rp_cpu_needs_gp); |
4605c014 | 351 | seq_printf(m, "gpc=%ld gps=%ld nn=%ld\n", |
7ba5c840 PM |
352 | rdp->n_rp_gp_completed, |
353 | rdp->n_rp_gp_started, | |
7ba5c840 PM |
354 | rdp->n_rp_need_nothing); |
355 | } | |
356 | ||
c011c41f | 357 | static int show_rcu_pending(struct seq_file *m, void *v) |
51d0f16d MW |
358 | { |
359 | print_one_rcu_pending(m, (struct rcu_data *)v); | |
360 | return 0; | |
361 | } | |
362 | ||
c011c41f | 363 | static const struct seq_operations rcu_pending_op = { |
51d0f16d MW |
364 | .start = r_start, |
365 | .next = r_next, | |
366 | .stop = r_stop, | |
c011c41f | 367 | .show = show_rcu_pending, |
51d0f16d MW |
368 | }; |
369 | ||
c011c41f | 370 | static int rcu_pending_open(struct inode *inode, struct file *file) |
51d0f16d | 371 | { |
c011c41f | 372 | return r_open(inode, file, &rcu_pending_op); |
51d0f16d MW |
373 | } |
374 | ||
c011c41f | 375 | static const struct file_operations rcu_pending_fops = { |
51d0f16d | 376 | .owner = THIS_MODULE, |
c011c41f | 377 | .open = rcu_pending_open, |
51d0f16d MW |
378 | .read = seq_read, |
379 | .llseek = no_llseek, | |
380 | .release = seq_release, | |
381 | }; | |
382 | ||
4a298656 PM |
383 | static int show_rcutorture(struct seq_file *m, void *unused) |
384 | { | |
385 | seq_printf(m, "rcutorture test sequence: %lu %s\n", | |
386 | rcutorture_testseq >> 1, | |
387 | (rcutorture_testseq & 0x1) ? "(test in progress)" : ""); | |
388 | seq_printf(m, "rcutorture update version number: %lu\n", | |
389 | rcutorture_vernum); | |
390 | return 0; | |
391 | } | |
392 | ||
393 | static int rcutorture_open(struct inode *inode, struct file *file) | |
394 | { | |
395 | return single_open(file, show_rcutorture, NULL); | |
396 | } | |
397 | ||
398 | static const struct file_operations rcutorture_fops = { | |
399 | .owner = THIS_MODULE, | |
400 | .open = rcutorture_open, | |
401 | .read = seq_read, | |
402 | .llseek = seq_lseek, | |
403 | .release = single_release, | |
404 | }; | |
405 | ||
7ba5c840 | 406 | static struct dentry *rcudir; |
7ba5c840 | 407 | |
deb7a418 | 408 | static int __init rcutree_trace_init(void) |
64db4cff | 409 | { |
573bcd40 | 410 | struct rcu_state *rsp; |
22f00b69 | 411 | struct dentry *retval; |
573bcd40 | 412 | struct dentry *rspdir; |
22f00b69 | 413 | |
64db4cff PM |
414 | rcudir = debugfs_create_dir("rcu", NULL); |
415 | if (!rcudir) | |
22f00b69 | 416 | goto free_out; |
64db4cff | 417 | |
573bcd40 MW |
418 | for_each_rcu_flavor(rsp) { |
419 | rspdir = debugfs_create_dir(rsp->name, rcudir); | |
420 | if (!rspdir) | |
421 | goto free_out; | |
878eda72 MW |
422 | |
423 | retval = debugfs_create_file("rcudata", 0444, | |
c011c41f | 424 | rspdir, rsp, &rcudata_fops); |
878eda72 MW |
425 | if (!retval) |
426 | goto free_out; | |
51d0f16d MW |
427 | |
428 | retval = debugfs_create_file("rcu_pending", 0444, | |
c011c41f | 429 | rspdir, rsp, &rcu_pending_fops); |
51d0f16d MW |
430 | if (!retval) |
431 | goto free_out; | |
573bcd40 MW |
432 | } |
433 | ||
d7e187c8 PM |
434 | retval = debugfs_create_file("rcubarrier", 0444, rcudir, |
435 | NULL, &rcubarrier_fops); | |
436 | if (!retval) | |
437 | goto free_out; | |
438 | ||
0ea1f2eb PM |
439 | if (rcu_boost_trace_create_file(rcudir)) |
440 | goto free_out; | |
441 | ||
22f00b69 PM |
442 | retval = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops); |
443 | if (!retval) | |
64db4cff PM |
444 | goto free_out; |
445 | ||
22f00b69 | 446 | retval = debugfs_create_file("rcuhier", 0444, rcudir, |
64db4cff | 447 | NULL, &rcuhier_fops); |
22f00b69 | 448 | if (!retval) |
64db4cff | 449 | goto free_out; |
7ba5c840 | 450 | |
4a298656 PM |
451 | retval = debugfs_create_file("rcutorture", 0444, rcudir, |
452 | NULL, &rcutorture_fops); | |
453 | if (!retval) | |
454 | goto free_out; | |
64db4cff PM |
455 | return 0; |
456 | free_out: | |
22f00b69 | 457 | debugfs_remove_recursive(rcudir); |
64db4cff PM |
458 | return 1; |
459 | } | |
460 | ||
deb7a418 | 461 | static void __exit rcutree_trace_cleanup(void) |
64db4cff | 462 | { |
22f00b69 | 463 | debugfs_remove_recursive(rcudir); |
64db4cff PM |
464 | } |
465 | ||
466 | ||
deb7a418 PM |
467 | module_init(rcutree_trace_init); |
468 | module_exit(rcutree_trace_cleanup); | |
64db4cff PM |
469 | |
470 | MODULE_AUTHOR("Paul E. McKenney"); | |
471 | MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation"); | |
472 | MODULE_LICENSE("GPL"); |