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27#include <linux/types.h>
28#include <linux/kernel.h>
29#include <linux/init.h>
30#include <linux/spinlock.h>
31#include <linux/smp.h>
32#include <linux/rcupdate.h>
33#include <linux/interrupt.h>
34#include <linux/sched.h>
35#include <linux/atomic.h>
36#include <linux/bitops.h>
37#include <linux/completion.h>
38#include <linux/percpu.h>
39#include <linux/notifier.h>
40#include <linux/cpu.h>
41#include <linux/mutex.h>
42#include <linux/debugfs.h>
43#include <linux/seq_file.h>
44
45#define RCU_TREE_NONCORE
46#include "tree.h"
47
48DECLARE_PER_CPU_SHARED_ALIGNED(unsigned long, rcu_qs_ctr);
49
50static int r_open(struct inode *inode, struct file *file,
51 const struct seq_operations *op)
52{
53 int ret = seq_open(file, op);
54 if (!ret) {
55 struct seq_file *m = (struct seq_file *)file->private_data;
56 m->private = inode->i_private;
57 }
58 return ret;
59}
60
61static void *r_start(struct seq_file *m, loff_t *pos)
62{
63 struct rcu_state *rsp = (struct rcu_state *)m->private;
64 *pos = cpumask_next(*pos - 1, cpu_possible_mask);
65 if ((*pos) < nr_cpu_ids)
66 return per_cpu_ptr(rsp->rda, *pos);
67 return NULL;
68}
69
70static void *r_next(struct seq_file *m, void *v, loff_t *pos)
71{
72 (*pos)++;
73 return r_start(m, pos);
74}
75
76static void r_stop(struct seq_file *m, void *v)
77{
78}
79
80static int show_rcubarrier(struct seq_file *m, void *v)
81{
82 struct rcu_state *rsp = (struct rcu_state *)m->private;
83 seq_printf(m, "bcc: %d bseq: %lu\n",
84 atomic_read(&rsp->barrier_cpu_count),
85 rsp->barrier_sequence);
86 return 0;
87}
88
89static int rcubarrier_open(struct inode *inode, struct file *file)
90{
91 return single_open(file, show_rcubarrier, inode->i_private);
92}
93
94static const struct file_operations rcubarrier_fops = {
95 .owner = THIS_MODULE,
96 .open = rcubarrier_open,
97 .read = seq_read,
98 .llseek = no_llseek,
99 .release = single_release,
100};
101
102#ifdef CONFIG_RCU_BOOST
103
104static char convert_kthread_status(unsigned int kthread_status)
105{
106 if (kthread_status > RCU_KTHREAD_MAX)
107 return '?';
108 return "SRWOY"[kthread_status];
109}
110
111#endif
112
113static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
114{
115 long ql, qll;
116
117 if (!rdp->beenonline)
118 return;
119 seq_printf(m, "%3d%cc=%ld g=%ld cnq=%d/%d:%d",
120 rdp->cpu,
121 cpu_is_offline(rdp->cpu) ? '!' : ' ',
122 ulong2long(rdp->completed), ulong2long(rdp->gpnum),
123 rdp->cpu_no_qs.b.norm,
124 rdp->rcu_qs_ctr_snap == per_cpu(rcu_qs_ctr, rdp->cpu),
125 rdp->core_needs_qs);
126 seq_printf(m, " dt=%d/%llx/%d df=%lu",
127 atomic_read(&rdp->dynticks->dynticks),
128 rdp->dynticks->dynticks_nesting,
129 rdp->dynticks->dynticks_nmi_nesting,
130 rdp->dynticks_fqs);
131 seq_printf(m, " of=%lu", rdp->offline_fqs);
132 rcu_nocb_q_lengths(rdp, &ql, &qll);
133 qll += rdp->qlen_lazy;
134 ql += rdp->qlen;
135 seq_printf(m, " ql=%ld/%ld qs=%c%c%c%c",
136 qll, ql,
137 ".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
138 rdp->nxttail[RCU_NEXT_TAIL]],
139 ".R"[rdp->nxttail[RCU_WAIT_TAIL] !=
140 rdp->nxttail[RCU_NEXT_READY_TAIL]],
141 ".W"[rdp->nxttail[RCU_DONE_TAIL] !=
142 rdp->nxttail[RCU_WAIT_TAIL]],
143 ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]);
144#ifdef CONFIG_RCU_BOOST
145 seq_printf(m, " kt=%d/%c ktl=%x",
146 per_cpu(rcu_cpu_has_work, rdp->cpu),
147 convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
148 rdp->cpu)),
149 per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff);
150#endif
151 seq_printf(m, " b=%ld", rdp->blimit);
152 seq_printf(m, " ci=%lu nci=%lu co=%lu ca=%lu\n",
153 rdp->n_cbs_invoked, rdp->n_nocbs_invoked,
154 rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
155}
156
157static int show_rcudata(struct seq_file *m, void *v)
158{
159 print_one_rcu_data(m, (struct rcu_data *)v);
160 return 0;
161}
162
163static const struct seq_operations rcudate_op = {
164 .start = r_start,
165 .next = r_next,
166 .stop = r_stop,
167 .show = show_rcudata,
168};
169
170static int rcudata_open(struct inode *inode, struct file *file)
171{
172 return r_open(inode, file, &rcudate_op);
173}
174
175static const struct file_operations rcudata_fops = {
176 .owner = THIS_MODULE,
177 .open = rcudata_open,
178 .read = seq_read,
179 .llseek = no_llseek,
180 .release = seq_release,
181};
182
183static int show_rcuexp(struct seq_file *m, void *v)
184{
185 int cpu;
186 struct rcu_state *rsp = (struct rcu_state *)m->private;
187 struct rcu_data *rdp;
188 unsigned long s0 = 0, s1 = 0, s2 = 0, s3 = 0;
189
190 for_each_possible_cpu(cpu) {
191 rdp = per_cpu_ptr(rsp->rda, cpu);
192 s0 += atomic_long_read(&rdp->expedited_workdone0);
193 s1 += atomic_long_read(&rdp->expedited_workdone1);
194 s2 += atomic_long_read(&rdp->expedited_workdone2);
195 s3 += atomic_long_read(&rdp->expedited_workdone3);
196 }
197 seq_printf(m, "s=%lu wd0=%lu wd1=%lu wd2=%lu wd3=%lu n=%lu enq=%d sc=%lu\n",
198 rsp->expedited_sequence, s0, s1, s2, s3,
199 atomic_long_read(&rsp->expedited_normal),
200 atomic_read(&rsp->expedited_need_qs),
201 rsp->expedited_sequence / 2);
202 return 0;
203}
204
205static int rcuexp_open(struct inode *inode, struct file *file)
206{
207 return single_open(file, show_rcuexp, inode->i_private);
208}
209
210static const struct file_operations rcuexp_fops = {
211 .owner = THIS_MODULE,
212 .open = rcuexp_open,
213 .read = seq_read,
214 .llseek = no_llseek,
215 .release = single_release,
216};
217
218#ifdef CONFIG_RCU_BOOST
219
220static void print_one_rcu_node_boost(struct seq_file *m, struct rcu_node *rnp)
221{
222 seq_printf(m, "%d:%d tasks=%c%c%c%c kt=%c ntb=%lu neb=%lu nnb=%lu ",
223 rnp->grplo, rnp->grphi,
224 "T."[list_empty(&rnp->blkd_tasks)],
225 "N."[!rnp->gp_tasks],
226 "E."[!rnp->exp_tasks],
227 "B."[!rnp->boost_tasks],
228 convert_kthread_status(rnp->boost_kthread_status),
229 rnp->n_tasks_boosted, rnp->n_exp_boosts,
230 rnp->n_normal_boosts);
231 seq_printf(m, "j=%04x bt=%04x\n",
232 (int)(jiffies & 0xffff),
233 (int)(rnp->boost_time & 0xffff));
234 seq_printf(m, " balk: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n",
235 rnp->n_balk_blkd_tasks,
236 rnp->n_balk_exp_gp_tasks,
237 rnp->n_balk_boost_tasks,
238 rnp->n_balk_notblocked,
239 rnp->n_balk_notyet,
240 rnp->n_balk_nos);
241}
242
243static int show_rcu_node_boost(struct seq_file *m, void *unused)
244{
245 struct rcu_node *rnp;
246
247 rcu_for_each_leaf_node(&rcu_preempt_state, rnp)
248 print_one_rcu_node_boost(m, rnp);
249 return 0;
250}
251
252static int rcu_node_boost_open(struct inode *inode, struct file *file)
253{
254 return single_open(file, show_rcu_node_boost, NULL);
255}
256
257static const struct file_operations rcu_node_boost_fops = {
258 .owner = THIS_MODULE,
259 .open = rcu_node_boost_open,
260 .read = seq_read,
261 .llseek = no_llseek,
262 .release = single_release,
263};
264
265#endif
266
267static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
268{
269 unsigned long gpnum;
270 int level = 0;
271 struct rcu_node *rnp;
272
273 gpnum = rsp->gpnum;
274 seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x ",
275 ulong2long(rsp->completed), ulong2long(gpnum),
276 rsp->gp_state,
277 (long)(rsp->jiffies_force_qs - jiffies),
278 (int)(jiffies & 0xffff));
279 seq_printf(m, "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld/%ld\n",
280 rsp->n_force_qs, rsp->n_force_qs_ngp,
281 rsp->n_force_qs - rsp->n_force_qs_ngp,
282 READ_ONCE(rsp->n_force_qs_lh), rsp->qlen_lazy, rsp->qlen);
283 for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_nodes; rnp++) {
284 if (rnp->level != level) {
285 seq_puts(m, "\n");
286 level = rnp->level;
287 }
288 seq_printf(m, "%lx/%lx->%lx %c%c>%c %d:%d ^%d ",
289 rnp->qsmask, rnp->qsmaskinit, rnp->qsmaskinitnext,
290 ".G"[rnp->gp_tasks != NULL],
291 ".E"[rnp->exp_tasks != NULL],
292 ".T"[!list_empty(&rnp->blkd_tasks)],
293 rnp->grplo, rnp->grphi, rnp->grpnum);
294 }
295 seq_puts(m, "\n");
296}
297
298static int show_rcuhier(struct seq_file *m, void *v)
299{
300 struct rcu_state *rsp = (struct rcu_state *)m->private;
301 print_one_rcu_state(m, rsp);
302 return 0;
303}
304
305static int rcuhier_open(struct inode *inode, struct file *file)
306{
307 return single_open(file, show_rcuhier, inode->i_private);
308}
309
310static const struct file_operations rcuhier_fops = {
311 .owner = THIS_MODULE,
312 .open = rcuhier_open,
313 .read = seq_read,
314 .llseek = no_llseek,
315 .release = single_release,
316};
317
318static void show_one_rcugp(struct seq_file *m, struct rcu_state *rsp)
319{
320 unsigned long flags;
321 unsigned long completed;
322 unsigned long gpnum;
323 unsigned long gpage;
324 unsigned long gpmax;
325 struct rcu_node *rnp = &rsp->node[0];
326
327 raw_spin_lock_irqsave_rcu_node(rnp, flags);
328 completed = READ_ONCE(rsp->completed);
329 gpnum = READ_ONCE(rsp->gpnum);
330 if (completed == gpnum)
331 gpage = 0;
332 else
333 gpage = jiffies - rsp->gp_start;
334 gpmax = rsp->gp_max;
335 raw_spin_unlock_irqrestore(&rnp->lock, flags);
336 seq_printf(m, "completed=%ld gpnum=%ld age=%ld max=%ld\n",
337 ulong2long(completed), ulong2long(gpnum), gpage, gpmax);
338}
339
340static int show_rcugp(struct seq_file *m, void *v)
341{
342 struct rcu_state *rsp = (struct rcu_state *)m->private;
343 show_one_rcugp(m, rsp);
344 return 0;
345}
346
347static int rcugp_open(struct inode *inode, struct file *file)
348{
349 return single_open(file, show_rcugp, inode->i_private);
350}
351
352static const struct file_operations rcugp_fops = {
353 .owner = THIS_MODULE,
354 .open = rcugp_open,
355 .read = seq_read,
356 .llseek = no_llseek,
357 .release = single_release,
358};
359
360static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
361{
362 if (!rdp->beenonline)
363 return;
364 seq_printf(m, "%3d%cnp=%ld ",
365 rdp->cpu,
366 cpu_is_offline(rdp->cpu) ? '!' : ' ',
367 rdp->n_rcu_pending);
368 seq_printf(m, "qsp=%ld rpq=%ld cbr=%ld cng=%ld ",
369 rdp->n_rp_core_needs_qs,
370 rdp->n_rp_report_qs,
371 rdp->n_rp_cb_ready,
372 rdp->n_rp_cpu_needs_gp);
373 seq_printf(m, "gpc=%ld gps=%ld nn=%ld ndw%ld\n",
374 rdp->n_rp_gp_completed,
375 rdp->n_rp_gp_started,
376 rdp->n_rp_nocb_defer_wakeup,
377 rdp->n_rp_need_nothing);
378}
379
380static int show_rcu_pending(struct seq_file *m, void *v)
381{
382 print_one_rcu_pending(m, (struct rcu_data *)v);
383 return 0;
384}
385
386static const struct seq_operations rcu_pending_op = {
387 .start = r_start,
388 .next = r_next,
389 .stop = r_stop,
390 .show = show_rcu_pending,
391};
392
393static int rcu_pending_open(struct inode *inode, struct file *file)
394{
395 return r_open(inode, file, &rcu_pending_op);
396}
397
398static const struct file_operations rcu_pending_fops = {
399 .owner = THIS_MODULE,
400 .open = rcu_pending_open,
401 .read = seq_read,
402 .llseek = no_llseek,
403 .release = seq_release,
404};
405
406static int show_rcutorture(struct seq_file *m, void *unused)
407{
408 seq_printf(m, "rcutorture test sequence: %lu %s\n",
409 rcutorture_testseq >> 1,
410 (rcutorture_testseq & 0x1) ? "(test in progress)" : "");
411 seq_printf(m, "rcutorture update version number: %lu\n",
412 rcutorture_vernum);
413 return 0;
414}
415
416static int rcutorture_open(struct inode *inode, struct file *file)
417{
418 return single_open(file, show_rcutorture, NULL);
419}
420
421static const struct file_operations rcutorture_fops = {
422 .owner = THIS_MODULE,
423 .open = rcutorture_open,
424 .read = seq_read,
425 .llseek = seq_lseek,
426 .release = single_release,
427};
428
429static struct dentry *rcudir;
430
431static int __init rcutree_trace_init(void)
432{
433 struct rcu_state *rsp;
434 struct dentry *retval;
435 struct dentry *rspdir;
436
437 rcudir = debugfs_create_dir("rcu", NULL);
438 if (!rcudir)
439 goto free_out;
440
441 for_each_rcu_flavor(rsp) {
442 rspdir = debugfs_create_dir(rsp->name, rcudir);
443 if (!rspdir)
444 goto free_out;
445
446 retval = debugfs_create_file("rcudata", 0444,
447 rspdir, rsp, &rcudata_fops);
448 if (!retval)
449 goto free_out;
450
451 retval = debugfs_create_file("rcuexp", 0444,
452 rspdir, rsp, &rcuexp_fops);
453 if (!retval)
454 goto free_out;
455
456 retval = debugfs_create_file("rcu_pending", 0444,
457 rspdir, rsp, &rcu_pending_fops);
458 if (!retval)
459 goto free_out;
460
461 retval = debugfs_create_file("rcubarrier", 0444,
462 rspdir, rsp, &rcubarrier_fops);
463 if (!retval)
464 goto free_out;
465
466#ifdef CONFIG_RCU_BOOST
467 if (rsp == &rcu_preempt_state) {
468 retval = debugfs_create_file("rcuboost", 0444,
469 rspdir, NULL, &rcu_node_boost_fops);
470 if (!retval)
471 goto free_out;
472 }
473#endif
474
475 retval = debugfs_create_file("rcugp", 0444,
476 rspdir, rsp, &rcugp_fops);
477 if (!retval)
478 goto free_out;
479
480 retval = debugfs_create_file("rcuhier", 0444,
481 rspdir, rsp, &rcuhier_fops);
482 if (!retval)
483 goto free_out;
484 }
485
486 retval = debugfs_create_file("rcutorture", 0444, rcudir,
487 NULL, &rcutorture_fops);
488 if (!retval)
489 goto free_out;
490 return 0;
491free_out:
492 debugfs_remove_recursive(rcudir);
493 return 1;
494}
495device_initcall(rcutree_trace_init);
496
