rcu: Add callback-free CPUs
[GitHub/mt8127/android_kernel_alcatel_ttab.git] / kernel / rcutree_trace.c
CommitLineData
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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
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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>
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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
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47#include "rcutree.h"
48
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49#define ulong2long(a) (*(long *)(&(a)))
50
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51static 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
62static 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
71static void *r_next(struct seq_file *m, void *v, loff_t *pos)
72{
73 (*pos)++;
74 return r_start(m, pos);
75}
76
77static void r_stop(struct seq_file *m, void *v)
78{
79}
80
6ee0886f 81static int show_rcubarrier(struct seq_file *m, void *v)
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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 90static int rcubarrier_open(struct inode *inode, struct file *file)
c25e557f 91{
6ee0886f 92 return single_open(file, show_rcubarrier, inode->i_private);
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93}
94
6ee0886f 95static const struct file_operations rcubarrier_fops = {
c25e557f 96 .owner = THIS_MODULE,
6ee0886f 97 .open = rcubarrier_open,
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98 .read = seq_read,
99 .llseek = no_llseek,
100 .release = seq_release,
101};
102
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103#ifdef CONFIG_RCU_BOOST
104
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105static char convert_kthread_status(unsigned int kthread_status)
106{
107 if (kthread_status > RCU_KTHREAD_MAX)
108 return '?';
15ba0ba8 109 return "SRWOY"[kthread_status];
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110}
111
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112#endif /* #ifdef CONFIG_RCU_BOOST */
113
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114static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
115{
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116 long ql, qll;
117
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118 if (!rdp->beenonline)
119 return;
42c3533e 120 seq_printf(m, "%3d%cc=%ld g=%ld pq=%d qp=%d",
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121 rdp->cpu,
122 cpu_is_offline(rdp->cpu) ? '!' : ' ',
42c3533e 123 ulong2long(rdp->completed), ulong2long(rdp->gpnum),
d7d6a11e 124 rdp->passed_quiesce, rdp->qs_pending);
9b2e4f18 125 seq_printf(m, " dt=%d/%llx/%d df=%lu",
23b5c8fa 126 atomic_read(&rdp->dynticks->dynticks),
64db4cff 127 rdp->dynticks->dynticks_nesting,
23b5c8fa 128 rdp->dynticks->dynticks_nmi_nesting,
64db4cff 129 rdp->dynticks_fqs);
2036d94a 130 seq_printf(m, " of=%lu", rdp->offline_fqs);
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131 rcu_nocb_q_lengths(rdp, &ql, &qll);
132 qll += rdp->qlen_lazy;
133 ql += rdp->qlen;
486e2593 134 seq_printf(m, " ql=%ld/%ld qs=%c%c%c%c",
3fbfbf7a 135 qll, ql,
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136 ".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
137 rdp->nxttail[RCU_NEXT_TAIL]],
138 ".R"[rdp->nxttail[RCU_WAIT_TAIL] !=
139 rdp->nxttail[RCU_NEXT_READY_TAIL]],
140 ".W"[rdp->nxttail[RCU_DONE_TAIL] !=
141 rdp->nxttail[RCU_WAIT_TAIL]],
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142 ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]);
143#ifdef CONFIG_RCU_BOOST
62ab7072 144 seq_printf(m, " kt=%d/%c ktl=%x",
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145 per_cpu(rcu_cpu_has_work, rdp->cpu),
146 convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
147 rdp->cpu)),
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148 per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff);
149#endif /* #ifdef CONFIG_RCU_BOOST */
150 seq_printf(m, " b=%ld", rdp->blimit);
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151 seq_printf(m, " ci=%lu co=%lu ca=%lu\n",
152 rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
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153}
154
c011c41f 155static int show_rcudata(struct seq_file *m, void *v)
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156{
157 print_one_rcu_data(m, (struct rcu_data *)v);
158 return 0;
159}
160
c011c41f 161static const struct seq_operations rcudate_op = {
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162 .start = r_start,
163 .next = r_next,
164 .stop = r_stop,
c011c41f 165 .show = show_rcudata,
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166};
167
c011c41f 168static int rcudata_open(struct inode *inode, struct file *file)
878eda72 169{
c011c41f 170 return r_open(inode, file, &rcudate_op);
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171}
172
c011c41f 173static const struct file_operations rcudata_fops = {
878eda72 174 .owner = THIS_MODULE,
c011c41f 175 .open = rcudata_open,
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176 .read = seq_read,
177 .llseek = no_llseek,
178 .release = seq_release,
179};
180
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181static int show_rcuexp(struct seq_file *m, void *v)
182{
183 struct rcu_state *rsp = (struct rcu_state *)m->private;
184
185 seq_printf(m, "s=%lu d=%lu w=%lu tf=%lu wd1=%lu wd2=%lu n=%lu sc=%lu dt=%lu dl=%lu dx=%lu\n",
186 atomic_long_read(&rsp->expedited_start),
187 atomic_long_read(&rsp->expedited_done),
188 atomic_long_read(&rsp->expedited_wrap),
189 atomic_long_read(&rsp->expedited_tryfail),
190 atomic_long_read(&rsp->expedited_workdone1),
191 atomic_long_read(&rsp->expedited_workdone2),
192 atomic_long_read(&rsp->expedited_normal),
193 atomic_long_read(&rsp->expedited_stoppedcpus),
194 atomic_long_read(&rsp->expedited_done_tries),
195 atomic_long_read(&rsp->expedited_done_lost),
196 atomic_long_read(&rsp->expedited_done_exit));
197 return 0;
198}
199
200static int rcuexp_open(struct inode *inode, struct file *file)
201{
202 return single_open(file, show_rcuexp, inode->i_private);
203}
204
205static const struct file_operations rcuexp_fops = {
206 .owner = THIS_MODULE,
207 .open = rcuexp_open,
208 .read = seq_read,
209 .llseek = no_llseek,
210 .release = seq_release,
211};
212
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213#ifdef CONFIG_RCU_BOOST
214
215static void print_one_rcu_node_boost(struct seq_file *m, struct rcu_node *rnp)
216{
5cf05ad7 217 seq_printf(m, "%d:%d tasks=%c%c%c%c kt=%c ntb=%lu neb=%lu nnb=%lu ",
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218 rnp->grplo, rnp->grphi,
219 "T."[list_empty(&rnp->blkd_tasks)],
220 "N."[!rnp->gp_tasks],
221 "E."[!rnp->exp_tasks],
222 "B."[!rnp->boost_tasks],
d71df90e 223 convert_kthread_status(rnp->boost_kthread_status),
0ea1f2eb 224 rnp->n_tasks_boosted, rnp->n_exp_boosts,
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225 rnp->n_normal_boosts);
226 seq_printf(m, "j=%04x bt=%04x\n",
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227 (int)(jiffies & 0xffff),
228 (int)(rnp->boost_time & 0xffff));
5cf05ad7 229 seq_printf(m, " balk: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n",
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230 rnp->n_balk_blkd_tasks,
231 rnp->n_balk_exp_gp_tasks,
232 rnp->n_balk_boost_tasks,
233 rnp->n_balk_notblocked,
234 rnp->n_balk_notyet,
235 rnp->n_balk_nos);
236}
237
238static int show_rcu_node_boost(struct seq_file *m, void *unused)
239{
240 struct rcu_node *rnp;
241
242 rcu_for_each_leaf_node(&rcu_preempt_state, rnp)
243 print_one_rcu_node_boost(m, rnp);
244 return 0;
245}
246
247static int rcu_node_boost_open(struct inode *inode, struct file *file)
248{
249 return single_open(file, show_rcu_node_boost, NULL);
250}
251
252static const struct file_operations rcu_node_boost_fops = {
253 .owner = THIS_MODULE,
254 .open = rcu_node_boost_open,
255 .read = seq_read,
29c67764 256 .llseek = no_llseek,
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257 .release = single_release,
258};
259
6ee0886f 260#endif /* #ifdef CONFIG_RCU_BOOST */
0ea1f2eb 261
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262static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
263{
20133cfc 264 unsigned long gpnum;
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265 int level = 0;
266 struct rcu_node *rnp;
267
3397e040 268 gpnum = rsp->gpnum;
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269 seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x ",
270 ulong2long(rsp->completed), ulong2long(gpnum),
42c3533e 271 rsp->fqs_state,
64db4cff 272 (long)(rsp->jiffies_force_qs - jiffies),
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273 (int)(jiffies & 0xffff));
274 seq_printf(m, "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld/%ld\n",
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275 rsp->n_force_qs, rsp->n_force_qs_ngp,
276 rsp->n_force_qs - rsp->n_force_qs_ngp,
b1420f1c 277 rsp->n_force_qs_lh, rsp->qlen_lazy, rsp->qlen);
f885b7f2 278 for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_nodes; rnp++) {
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279 if (rnp->level != level) {
280 seq_puts(m, "\n");
281 level = rnp->level;
282 }
12f5f524 283 seq_printf(m, "%lx/%lx %c%c>%c %d:%d ^%d ",
64db4cff 284 rnp->qsmask, rnp->qsmaskinit,
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285 ".G"[rnp->gp_tasks != NULL],
286 ".E"[rnp->exp_tasks != NULL],
287 ".T"[!list_empty(&rnp->blkd_tasks)],
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288 rnp->grplo, rnp->grphi, rnp->grpnum);
289 }
290 seq_puts(m, "\n");
291}
292
6ee0886f 293static int show_rcuhier(struct seq_file *m, void *v)
64db4cff 294{
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295 struct rcu_state *rsp = (struct rcu_state *)m->private;
296 print_one_rcu_state(m, rsp);
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297 return 0;
298}
299
300static int rcuhier_open(struct inode *inode, struct file *file)
301{
6ee0886f 302 return single_open(file, show_rcuhier, inode->i_private);
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303}
304
9b2619af 305static const struct file_operations rcuhier_fops = {
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306 .owner = THIS_MODULE,
307 .open = rcuhier_open,
308 .read = seq_read,
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309 .llseek = no_llseek,
310 .release = seq_release,
311};
312
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313static void show_one_rcugp(struct seq_file *m, struct rcu_state *rsp)
314{
315 unsigned long flags;
316 unsigned long completed;
317 unsigned long gpnum;
318 unsigned long gpage;
319 unsigned long gpmax;
320 struct rcu_node *rnp = &rsp->node[0];
321
322 raw_spin_lock_irqsave(&rnp->lock, flags);
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323 completed = ACCESS_ONCE(rsp->completed);
324 gpnum = ACCESS_ONCE(rsp->gpnum);
325 if (completed == gpnum)
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326 gpage = 0;
327 else
328 gpage = jiffies - rsp->gp_start;
329 gpmax = rsp->gp_max;
330 raw_spin_unlock_irqrestore(&rnp->lock, flags);
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331 seq_printf(m, "completed=%ld gpnum=%ld age=%ld max=%ld\n",
332 ulong2long(completed), ulong2long(gpnum), gpage, gpmax);
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333}
334
6ee0886f 335static int show_rcugp(struct seq_file *m, void *v)
64db4cff 336{
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337 struct rcu_state *rsp = (struct rcu_state *)m->private;
338 show_one_rcugp(m, rsp);
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339 return 0;
340}
341
342static int rcugp_open(struct inode *inode, struct file *file)
343{
6ee0886f 344 return single_open(file, show_rcugp, inode->i_private);
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345}
346
9b2619af 347static const struct file_operations rcugp_fops = {
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348 .owner = THIS_MODULE,
349 .open = rcugp_open,
350 .read = seq_read,
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351 .llseek = no_llseek,
352 .release = seq_release,
353};
354
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355static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
356{
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357 if (!rdp->beenonline)
358 return;
5cf05ad7 359 seq_printf(m, "%3d%cnp=%ld ",
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360 rdp->cpu,
361 cpu_is_offline(rdp->cpu) ? '!' : ' ',
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362 rdp->n_rcu_pending);
363 seq_printf(m, "qsp=%ld rpq=%ld cbr=%ld cng=%ld ",
7ba5c840 364 rdp->n_rp_qs_pending,
d21670ac 365 rdp->n_rp_report_qs,
7ba5c840 366 rdp->n_rp_cb_ready,
5cf05ad7 367 rdp->n_rp_cpu_needs_gp);
4605c014 368 seq_printf(m, "gpc=%ld gps=%ld nn=%ld\n",
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369 rdp->n_rp_gp_completed,
370 rdp->n_rp_gp_started,
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371 rdp->n_rp_need_nothing);
372}
373
c011c41f 374static int show_rcu_pending(struct seq_file *m, void *v)
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375{
376 print_one_rcu_pending(m, (struct rcu_data *)v);
377 return 0;
378}
379
c011c41f 380static const struct seq_operations rcu_pending_op = {
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381 .start = r_start,
382 .next = r_next,
383 .stop = r_stop,
c011c41f 384 .show = show_rcu_pending,
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385};
386
c011c41f 387static int rcu_pending_open(struct inode *inode, struct file *file)
51d0f16d 388{
c011c41f 389 return r_open(inode, file, &rcu_pending_op);
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390}
391
c011c41f 392static const struct file_operations rcu_pending_fops = {
51d0f16d 393 .owner = THIS_MODULE,
c011c41f 394 .open = rcu_pending_open,
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395 .read = seq_read,
396 .llseek = no_llseek,
397 .release = seq_release,
398};
399
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400static int show_rcutorture(struct seq_file *m, void *unused)
401{
402 seq_printf(m, "rcutorture test sequence: %lu %s\n",
403 rcutorture_testseq >> 1,
404 (rcutorture_testseq & 0x1) ? "(test in progress)" : "");
405 seq_printf(m, "rcutorture update version number: %lu\n",
406 rcutorture_vernum);
407 return 0;
408}
409
410static int rcutorture_open(struct inode *inode, struct file *file)
411{
412 return single_open(file, show_rcutorture, NULL);
413}
414
415static const struct file_operations rcutorture_fops = {
416 .owner = THIS_MODULE,
417 .open = rcutorture_open,
418 .read = seq_read,
419 .llseek = seq_lseek,
420 .release = single_release,
421};
422
7ba5c840 423static struct dentry *rcudir;
7ba5c840 424
deb7a418 425static int __init rcutree_trace_init(void)
64db4cff 426{
573bcd40 427 struct rcu_state *rsp;
22f00b69 428 struct dentry *retval;
573bcd40 429 struct dentry *rspdir;
22f00b69 430
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431 rcudir = debugfs_create_dir("rcu", NULL);
432 if (!rcudir)
22f00b69 433 goto free_out;
64db4cff 434
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435 for_each_rcu_flavor(rsp) {
436 rspdir = debugfs_create_dir(rsp->name, rcudir);
437 if (!rspdir)
438 goto free_out;
878eda72 439
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440 retval = debugfs_create_file("rcudata", 0444,
441 rspdir, rsp, &rcudata_fops);
442 if (!retval)
443 goto free_out;
51d0f16d 444
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445 retval = debugfs_create_file("rcuexp", 0444,
446 rspdir, rsp, &rcuexp_fops);
447 if (!retval)
448 goto free_out;
449
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450 retval = debugfs_create_file("rcu_pending", 0444,
451 rspdir, rsp, &rcu_pending_fops);
452 if (!retval)
453 goto free_out;
c25e557f 454
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455 retval = debugfs_create_file("rcubarrier", 0444,
456 rspdir, rsp, &rcubarrier_fops);
457 if (!retval)
458 goto free_out;
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459
460#ifdef CONFIG_RCU_BOOST
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461 if (rsp == &rcu_preempt_state) {
462 retval = debugfs_create_file("rcuboost", 0444,
463 rspdir, NULL, &rcu_node_boost_fops);
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464 if (!retval)
465 goto free_out;
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466 }
467#endif
66b38bc5 468
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469 retval = debugfs_create_file("rcugp", 0444,
470 rspdir, rsp, &rcugp_fops);
471 if (!retval)
472 goto free_out;
64db4cff 473
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474 retval = debugfs_create_file("rcuhier", 0444,
475 rspdir, rsp, &rcuhier_fops);
476 if (!retval)
477 goto free_out;
478 }
7ba5c840 479
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480 retval = debugfs_create_file("rcutorture", 0444, rcudir,
481 NULL, &rcutorture_fops);
482 if (!retval)
483 goto free_out;
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484 return 0;
485free_out:
22f00b69 486 debugfs_remove_recursive(rcudir);
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487 return 1;
488}
489
deb7a418 490static void __exit rcutree_trace_cleanup(void)
64db4cff 491{
22f00b69 492 debugfs_remove_recursive(rcudir);
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493}
494
495
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496module_init(rcutree_trace_init);
497module_exit(rcutree_trace_cleanup);
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498
499MODULE_AUTHOR("Paul E. McKenney");
500MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
501MODULE_LICENSE("GPL");