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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 | ||
42c3533e PM |
49 | #define ulong2long(a) (*(long *)(&(a))) |
50 | ||
374b928e MW |
51 | static int r_open(struct inode *inode, struct file *file, |
52 | const struct seq_operations *op) | |
53 | { | |
54 | int ret = seq_open(file, op); | |
55 | if (!ret) { | |
56 | struct seq_file *m = (struct seq_file *)file->private_data; | |
57 | m->private = inode->i_private; | |
58 | } | |
59 | return ret; | |
60 | } | |
61 | ||
62 | static void *r_start(struct seq_file *m, loff_t *pos) | |
63 | { | |
64 | struct rcu_state *rsp = (struct rcu_state *)m->private; | |
65 | *pos = cpumask_next(*pos - 1, cpu_possible_mask); | |
66 | if ((*pos) < nr_cpu_ids) | |
67 | return per_cpu_ptr(rsp->rda, *pos); | |
68 | return NULL; | |
69 | } | |
70 | ||
71 | static void *r_next(struct seq_file *m, void *v, loff_t *pos) | |
72 | { | |
73 | (*pos)++; | |
74 | return r_start(m, pos); | |
75 | } | |
76 | ||
77 | static void r_stop(struct seq_file *m, void *v) | |
78 | { | |
79 | } | |
80 | ||
6ee0886f | 81 | static int show_rcubarrier(struct seq_file *m, void *v) |
c25e557f MW |
82 | { |
83 | struct rcu_state *rsp = (struct rcu_state *)m->private; | |
84 | seq_printf(m, "bcc: %d nbd: %lu\n", | |
85 | atomic_read(&rsp->barrier_cpu_count), | |
86 | rsp->n_barrier_done); | |
87 | return 0; | |
88 | } | |
89 | ||
6ee0886f | 90 | static int rcubarrier_open(struct inode *inode, struct file *file) |
c25e557f | 91 | { |
6ee0886f | 92 | return single_open(file, show_rcubarrier, inode->i_private); |
c25e557f MW |
93 | } |
94 | ||
6ee0886f | 95 | static const struct file_operations rcubarrier_fops = { |
c25e557f | 96 | .owner = THIS_MODULE, |
6ee0886f | 97 | .open = rcubarrier_open, |
c25e557f MW |
98 | .read = seq_read, |
99 | .llseek = no_llseek, | |
100 | .release = seq_release, | |
101 | }; | |
102 | ||
a46e0899 PM |
103 | #ifdef CONFIG_RCU_BOOST |
104 | ||
d71df90e PM |
105 | static char convert_kthread_status(unsigned int kthread_status) |
106 | { | |
107 | if (kthread_status > RCU_KTHREAD_MAX) | |
108 | return '?'; | |
15ba0ba8 | 109 | return "SRWOY"[kthread_status]; |
d71df90e PM |
110 | } |
111 | ||
a46e0899 PM |
112 | #endif /* #ifdef CONFIG_RCU_BOOST */ |
113 | ||
64db4cff PM |
114 | static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp) |
115 | { | |
116 | if (!rdp->beenonline) | |
117 | return; | |
42c3533e | 118 | seq_printf(m, "%3d%cc=%ld g=%ld pq=%d qp=%d", |
64db4cff PM |
119 | rdp->cpu, |
120 | cpu_is_offline(rdp->cpu) ? '!' : ' ', | |
42c3533e | 121 | ulong2long(rdp->completed), ulong2long(rdp->gpnum), |
d7d6a11e | 122 | rdp->passed_quiesce, rdp->qs_pending); |
9b2e4f18 | 123 | seq_printf(m, " dt=%d/%llx/%d df=%lu", |
23b5c8fa | 124 | atomic_read(&rdp->dynticks->dynticks), |
64db4cff | 125 | rdp->dynticks->dynticks_nesting, |
23b5c8fa | 126 | rdp->dynticks->dynticks_nmi_nesting, |
64db4cff | 127 | rdp->dynticks_fqs); |
2036d94a | 128 | seq_printf(m, " of=%lu", rdp->offline_fqs); |
486e2593 PM |
129 | seq_printf(m, " ql=%ld/%ld qs=%c%c%c%c", |
130 | rdp->qlen_lazy, rdp->qlen, | |
0ac3d136 PM |
131 | ".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] != |
132 | rdp->nxttail[RCU_NEXT_TAIL]], | |
133 | ".R"[rdp->nxttail[RCU_WAIT_TAIL] != | |
134 | rdp->nxttail[RCU_NEXT_READY_TAIL]], | |
135 | ".W"[rdp->nxttail[RCU_DONE_TAIL] != | |
136 | rdp->nxttail[RCU_WAIT_TAIL]], | |
a46e0899 PM |
137 | ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]); |
138 | #ifdef CONFIG_RCU_BOOST | |
62ab7072 | 139 | seq_printf(m, " kt=%d/%c ktl=%x", |
d71df90e PM |
140 | per_cpu(rcu_cpu_has_work, rdp->cpu), |
141 | convert_kthread_status(per_cpu(rcu_cpu_kthread_status, | |
142 | rdp->cpu)), | |
a46e0899 PM |
143 | per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff); |
144 | #endif /* #ifdef CONFIG_RCU_BOOST */ | |
145 | seq_printf(m, " b=%ld", rdp->blimit); | |
269dcc1c PM |
146 | seq_printf(m, " ci=%lu co=%lu ca=%lu\n", |
147 | rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted); | |
64db4cff PM |
148 | } |
149 | ||
c011c41f | 150 | static int show_rcudata(struct seq_file *m, void *v) |
878eda72 MW |
151 | { |
152 | print_one_rcu_data(m, (struct rcu_data *)v); | |
153 | return 0; | |
154 | } | |
155 | ||
c011c41f | 156 | static const struct seq_operations rcudate_op = { |
878eda72 MW |
157 | .start = r_start, |
158 | .next = r_next, | |
159 | .stop = r_stop, | |
c011c41f | 160 | .show = show_rcudata, |
878eda72 MW |
161 | }; |
162 | ||
c011c41f | 163 | static int rcudata_open(struct inode *inode, struct file *file) |
878eda72 | 164 | { |
c011c41f | 165 | return r_open(inode, file, &rcudate_op); |
878eda72 MW |
166 | } |
167 | ||
c011c41f | 168 | static const struct file_operations rcudata_fops = { |
878eda72 | 169 | .owner = THIS_MODULE, |
c011c41f | 170 | .open = rcudata_open, |
878eda72 MW |
171 | .read = seq_read, |
172 | .llseek = no_llseek, | |
173 | .release = seq_release, | |
174 | }; | |
175 | ||
0ea1f2eb PM |
176 | #ifdef CONFIG_RCU_BOOST |
177 | ||
178 | static void print_one_rcu_node_boost(struct seq_file *m, struct rcu_node *rnp) | |
179 | { | |
5cf05ad7 | 180 | seq_printf(m, "%d:%d tasks=%c%c%c%c kt=%c ntb=%lu neb=%lu nnb=%lu ", |
0ea1f2eb PM |
181 | rnp->grplo, rnp->grphi, |
182 | "T."[list_empty(&rnp->blkd_tasks)], | |
183 | "N."[!rnp->gp_tasks], | |
184 | "E."[!rnp->exp_tasks], | |
185 | "B."[!rnp->boost_tasks], | |
d71df90e | 186 | convert_kthread_status(rnp->boost_kthread_status), |
0ea1f2eb | 187 | rnp->n_tasks_boosted, rnp->n_exp_boosts, |
5cf05ad7 PM |
188 | rnp->n_normal_boosts); |
189 | seq_printf(m, "j=%04x bt=%04x\n", | |
0ea1f2eb PM |
190 | (int)(jiffies & 0xffff), |
191 | (int)(rnp->boost_time & 0xffff)); | |
5cf05ad7 | 192 | seq_printf(m, " balk: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n", |
0ea1f2eb PM |
193 | rnp->n_balk_blkd_tasks, |
194 | rnp->n_balk_exp_gp_tasks, | |
195 | rnp->n_balk_boost_tasks, | |
196 | rnp->n_balk_notblocked, | |
197 | rnp->n_balk_notyet, | |
198 | rnp->n_balk_nos); | |
199 | } | |
200 | ||
201 | static int show_rcu_node_boost(struct seq_file *m, void *unused) | |
202 | { | |
203 | struct rcu_node *rnp; | |
204 | ||
205 | rcu_for_each_leaf_node(&rcu_preempt_state, rnp) | |
206 | print_one_rcu_node_boost(m, rnp); | |
207 | return 0; | |
208 | } | |
209 | ||
210 | static int rcu_node_boost_open(struct inode *inode, struct file *file) | |
211 | { | |
212 | return single_open(file, show_rcu_node_boost, NULL); | |
213 | } | |
214 | ||
215 | static const struct file_operations rcu_node_boost_fops = { | |
216 | .owner = THIS_MODULE, | |
217 | .open = rcu_node_boost_open, | |
218 | .read = seq_read, | |
29c67764 | 219 | .llseek = no_llseek, |
0ea1f2eb PM |
220 | .release = single_release, |
221 | }; | |
222 | ||
6ee0886f | 223 | #endif /* #ifdef CONFIG_RCU_BOOST */ |
0ea1f2eb | 224 | |
64db4cff PM |
225 | static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp) |
226 | { | |
20133cfc | 227 | unsigned long gpnum; |
64db4cff PM |
228 | int level = 0; |
229 | struct rcu_node *rnp; | |
230 | ||
3397e040 | 231 | gpnum = rsp->gpnum; |
6ee0886f MW |
232 | seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x ", |
233 | ulong2long(rsp->completed), ulong2long(gpnum), | |
42c3533e | 234 | rsp->fqs_state, |
64db4cff | 235 | (long)(rsp->jiffies_force_qs - jiffies), |
5cf05ad7 PM |
236 | (int)(jiffies & 0xffff)); |
237 | seq_printf(m, "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld/%ld\n", | |
64db4cff PM |
238 | rsp->n_force_qs, rsp->n_force_qs_ngp, |
239 | rsp->n_force_qs - rsp->n_force_qs_ngp, | |
b1420f1c | 240 | rsp->n_force_qs_lh, rsp->qlen_lazy, rsp->qlen); |
f885b7f2 | 241 | for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_nodes; rnp++) { |
64db4cff PM |
242 | if (rnp->level != level) { |
243 | seq_puts(m, "\n"); | |
244 | level = rnp->level; | |
245 | } | |
12f5f524 | 246 | seq_printf(m, "%lx/%lx %c%c>%c %d:%d ^%d ", |
64db4cff | 247 | rnp->qsmask, rnp->qsmaskinit, |
12f5f524 PM |
248 | ".G"[rnp->gp_tasks != NULL], |
249 | ".E"[rnp->exp_tasks != NULL], | |
250 | ".T"[!list_empty(&rnp->blkd_tasks)], | |
64db4cff PM |
251 | rnp->grplo, rnp->grphi, rnp->grpnum); |
252 | } | |
253 | seq_puts(m, "\n"); | |
254 | } | |
255 | ||
6ee0886f | 256 | static int show_rcuhier(struct seq_file *m, void *v) |
64db4cff | 257 | { |
6ee0886f MW |
258 | struct rcu_state *rsp = (struct rcu_state *)m->private; |
259 | print_one_rcu_state(m, rsp); | |
64db4cff PM |
260 | return 0; |
261 | } | |
262 | ||
263 | static int rcuhier_open(struct inode *inode, struct file *file) | |
264 | { | |
6ee0886f | 265 | return single_open(file, show_rcuhier, inode->i_private); |
64db4cff PM |
266 | } |
267 | ||
9b2619af | 268 | static const struct file_operations rcuhier_fops = { |
64db4cff PM |
269 | .owner = THIS_MODULE, |
270 | .open = rcuhier_open, | |
271 | .read = seq_read, | |
a608d84b MW |
272 | .llseek = no_llseek, |
273 | .release = seq_release, | |
274 | }; | |
275 | ||
15ba0ba8 PM |
276 | static void show_one_rcugp(struct seq_file *m, struct rcu_state *rsp) |
277 | { | |
278 | unsigned long flags; | |
279 | unsigned long completed; | |
280 | unsigned long gpnum; | |
281 | unsigned long gpage; | |
282 | unsigned long gpmax; | |
283 | struct rcu_node *rnp = &rsp->node[0]; | |
284 | ||
285 | raw_spin_lock_irqsave(&rnp->lock, flags); | |
42c3533e PM |
286 | completed = ACCESS_ONCE(rsp->completed); |
287 | gpnum = ACCESS_ONCE(rsp->gpnum); | |
288 | if (completed == gpnum) | |
15ba0ba8 PM |
289 | gpage = 0; |
290 | else | |
291 | gpage = jiffies - rsp->gp_start; | |
292 | gpmax = rsp->gp_max; | |
293 | raw_spin_unlock_irqrestore(&rnp->lock, flags); | |
6ee0886f MW |
294 | seq_printf(m, "completed=%ld gpnum=%ld age=%ld max=%ld\n", |
295 | ulong2long(completed), ulong2long(gpnum), gpage, gpmax); | |
15ba0ba8 PM |
296 | } |
297 | ||
6ee0886f | 298 | static int show_rcugp(struct seq_file *m, void *v) |
64db4cff | 299 | { |
6ee0886f MW |
300 | struct rcu_state *rsp = (struct rcu_state *)m->private; |
301 | show_one_rcugp(m, rsp); | |
64db4cff PM |
302 | return 0; |
303 | } | |
304 | ||
305 | static int rcugp_open(struct inode *inode, struct file *file) | |
306 | { | |
6ee0886f | 307 | return single_open(file, show_rcugp, inode->i_private); |
64db4cff PM |
308 | } |
309 | ||
9b2619af | 310 | static const struct file_operations rcugp_fops = { |
64db4cff PM |
311 | .owner = THIS_MODULE, |
312 | .open = rcugp_open, | |
313 | .read = seq_read, | |
66b38bc5 MW |
314 | .llseek = no_llseek, |
315 | .release = seq_release, | |
316 | }; | |
317 | ||
7ba5c840 PM |
318 | static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp) |
319 | { | |
51d0f16d MW |
320 | if (!rdp->beenonline) |
321 | return; | |
5cf05ad7 | 322 | seq_printf(m, "%3d%cnp=%ld ", |
7ba5c840 PM |
323 | rdp->cpu, |
324 | cpu_is_offline(rdp->cpu) ? '!' : ' ', | |
5cf05ad7 PM |
325 | rdp->n_rcu_pending); |
326 | seq_printf(m, "qsp=%ld rpq=%ld cbr=%ld cng=%ld ", | |
7ba5c840 | 327 | rdp->n_rp_qs_pending, |
d21670ac | 328 | rdp->n_rp_report_qs, |
7ba5c840 | 329 | rdp->n_rp_cb_ready, |
5cf05ad7 | 330 | rdp->n_rp_cpu_needs_gp); |
4605c014 | 331 | seq_printf(m, "gpc=%ld gps=%ld nn=%ld\n", |
7ba5c840 PM |
332 | rdp->n_rp_gp_completed, |
333 | rdp->n_rp_gp_started, | |
7ba5c840 PM |
334 | rdp->n_rp_need_nothing); |
335 | } | |
336 | ||
c011c41f | 337 | static int show_rcu_pending(struct seq_file *m, void *v) |
51d0f16d MW |
338 | { |
339 | print_one_rcu_pending(m, (struct rcu_data *)v); | |
340 | return 0; | |
341 | } | |
342 | ||
c011c41f | 343 | static const struct seq_operations rcu_pending_op = { |
51d0f16d MW |
344 | .start = r_start, |
345 | .next = r_next, | |
346 | .stop = r_stop, | |
c011c41f | 347 | .show = show_rcu_pending, |
51d0f16d MW |
348 | }; |
349 | ||
c011c41f | 350 | static int rcu_pending_open(struct inode *inode, struct file *file) |
51d0f16d | 351 | { |
c011c41f | 352 | return r_open(inode, file, &rcu_pending_op); |
51d0f16d MW |
353 | } |
354 | ||
c011c41f | 355 | static const struct file_operations rcu_pending_fops = { |
51d0f16d | 356 | .owner = THIS_MODULE, |
c011c41f | 357 | .open = rcu_pending_open, |
51d0f16d MW |
358 | .read = seq_read, |
359 | .llseek = no_llseek, | |
360 | .release = seq_release, | |
361 | }; | |
362 | ||
4a298656 PM |
363 | static int show_rcutorture(struct seq_file *m, void *unused) |
364 | { | |
365 | seq_printf(m, "rcutorture test sequence: %lu %s\n", | |
366 | rcutorture_testseq >> 1, | |
367 | (rcutorture_testseq & 0x1) ? "(test in progress)" : ""); | |
368 | seq_printf(m, "rcutorture update version number: %lu\n", | |
369 | rcutorture_vernum); | |
370 | return 0; | |
371 | } | |
372 | ||
373 | static int rcutorture_open(struct inode *inode, struct file *file) | |
374 | { | |
375 | return single_open(file, show_rcutorture, NULL); | |
376 | } | |
377 | ||
378 | static const struct file_operations rcutorture_fops = { | |
379 | .owner = THIS_MODULE, | |
380 | .open = rcutorture_open, | |
381 | .read = seq_read, | |
382 | .llseek = seq_lseek, | |
383 | .release = single_release, | |
384 | }; | |
385 | ||
7ba5c840 | 386 | static struct dentry *rcudir; |
7ba5c840 | 387 | |
deb7a418 | 388 | static int __init rcutree_trace_init(void) |
64db4cff | 389 | { |
573bcd40 | 390 | struct rcu_state *rsp; |
22f00b69 | 391 | struct dentry *retval; |
573bcd40 | 392 | struct dentry *rspdir; |
22f00b69 | 393 | |
64db4cff PM |
394 | rcudir = debugfs_create_dir("rcu", NULL); |
395 | if (!rcudir) | |
22f00b69 | 396 | goto free_out; |
64db4cff | 397 | |
573bcd40 MW |
398 | for_each_rcu_flavor(rsp) { |
399 | rspdir = debugfs_create_dir(rsp->name, rcudir); | |
400 | if (!rspdir) | |
401 | goto free_out; | |
878eda72 | 402 | |
6ee0886f MW |
403 | retval = debugfs_create_file("rcudata", 0444, |
404 | rspdir, rsp, &rcudata_fops); | |
405 | if (!retval) | |
406 | goto free_out; | |
51d0f16d | 407 | |
6ee0886f MW |
408 | retval = debugfs_create_file("rcu_pending", 0444, |
409 | rspdir, rsp, &rcu_pending_fops); | |
410 | if (!retval) | |
411 | goto free_out; | |
c25e557f | 412 | |
6ee0886f MW |
413 | retval = debugfs_create_file("rcubarrier", 0444, |
414 | rspdir, rsp, &rcubarrier_fops); | |
415 | if (!retval) | |
416 | goto free_out; | |
29c67764 MW |
417 | |
418 | #ifdef CONFIG_RCU_BOOST | |
6ee0886f MW |
419 | if (rsp == &rcu_preempt_state) { |
420 | retval = debugfs_create_file("rcuboost", 0444, | |
421 | rspdir, NULL, &rcu_node_boost_fops); | |
66b38bc5 MW |
422 | if (!retval) |
423 | goto free_out; | |
6ee0886f MW |
424 | } |
425 | #endif | |
66b38bc5 | 426 | |
6ee0886f MW |
427 | retval = debugfs_create_file("rcugp", 0444, |
428 | rspdir, rsp, &rcugp_fops); | |
429 | if (!retval) | |
430 | goto free_out; | |
64db4cff | 431 | |
6ee0886f MW |
432 | retval = debugfs_create_file("rcuhier", 0444, |
433 | rspdir, rsp, &rcuhier_fops); | |
434 | if (!retval) | |
435 | goto free_out; | |
436 | } | |
7ba5c840 | 437 | |
4a298656 PM |
438 | retval = debugfs_create_file("rcutorture", 0444, rcudir, |
439 | NULL, &rcutorture_fops); | |
440 | if (!retval) | |
441 | goto free_out; | |
64db4cff PM |
442 | return 0; |
443 | free_out: | |
22f00b69 | 444 | debugfs_remove_recursive(rcudir); |
64db4cff PM |
445 | return 1; |
446 | } | |
447 | ||
deb7a418 | 448 | static void __exit rcutree_trace_cleanup(void) |
64db4cff | 449 | { |
22f00b69 | 450 | debugfs_remove_recursive(rcudir); |
64db4cff PM |
451 | } |
452 | ||
453 | ||
deb7a418 PM |
454 | module_init(rcutree_trace_init); |
455 | module_exit(rcutree_trace_cleanup); | |
64db4cff PM |
456 | |
457 | MODULE_AUTHOR("Paul E. McKenney"); | |
458 | MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation"); | |
459 | MODULE_LICENSE("GPL"); |