projects/linux·blob v3.7 · refs

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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 -
23 * Documentation/RCU
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 <linux/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/cpu.h>
42#include <linux/mutex.h>
43#include <linux/debugfs.h>
44#include <linux/seq_file.h>
45
46#define RCU_TREE_NONCORE
47#include "rcutree.h"
48
49static int show_rcubarrier(struct seq_file *m, void *unused)
50{
51 struct rcu_state *rsp;
52
53 for_each_rcu_flavor(rsp)
54 seq_printf(m, "%s: bcc: %d nbd: %lu\n",
55 rsp->name,
56 atomic_read(&rsp->barrier_cpu_count),
57 rsp->n_barrier_done);
58 return 0;
59}
60
61static int rcubarrier_open(struct inode *inode, struct file *file)
62{
63 return single_open(file, show_rcubarrier, NULL);
64}
65
66static const struct file_operations rcubarrier_fops = {
67 .owner = THIS_MODULE,
68 .open = rcubarrier_open,
69 .read = seq_read,
70 .llseek = seq_lseek,
71 .release = single_release,
72};
73
74#ifdef CONFIG_RCU_BOOST
75
76static char convert_kthread_status(unsigned int kthread_status)
77{
78 if (kthread_status > RCU_KTHREAD_MAX)
79 return '?';
80 return "SRWOY"[kthread_status];
81}
82
83#endif /* #ifdef CONFIG_RCU_BOOST */
84
85static void print_one_rcu_data(struct seq_file *m, struct rcu_data *rdp)
86{
87 if (!rdp->beenonline)
88 return;
89 seq_printf(m, "%3d%cc=%lu g=%lu pq=%d qp=%d",
90 rdp->cpu,
91 cpu_is_offline(rdp->cpu) ? '!' : ' ',
92 rdp->completed, rdp->gpnum,
93 rdp->passed_quiesce, rdp->qs_pending);
94 seq_printf(m, " dt=%d/%llx/%d df=%lu",
95 atomic_read(&rdp->dynticks->dynticks),
96 rdp->dynticks->dynticks_nesting,
97 rdp->dynticks->dynticks_nmi_nesting,
98 rdp->dynticks_fqs);
99 seq_printf(m, " of=%lu", rdp->offline_fqs);
100 seq_printf(m, " ql=%ld/%ld qs=%c%c%c%c",
101 rdp->qlen_lazy, rdp->qlen,
102 ".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
103 rdp->nxttail[RCU_NEXT_TAIL]],
104 ".R"[rdp->nxttail[RCU_WAIT_TAIL] !=
105 rdp->nxttail[RCU_NEXT_READY_TAIL]],
106 ".W"[rdp->nxttail[RCU_DONE_TAIL] !=
107 rdp->nxttail[RCU_WAIT_TAIL]],
108 ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]);
109#ifdef CONFIG_RCU_BOOST
110 seq_printf(m, " kt=%d/%c ktl=%x",
111 per_cpu(rcu_cpu_has_work, rdp->cpu),
112 convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
113 rdp->cpu)),
114 per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff);
115#endif /* #ifdef CONFIG_RCU_BOOST */
116 seq_printf(m, " b=%ld", rdp->blimit);
117 seq_printf(m, " ci=%lu co=%lu ca=%lu\n",
118 rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
119}
120
121static int show_rcudata(struct seq_file *m, void *unused)
122{
123 int cpu;
124 struct rcu_state *rsp;
125
126 for_each_rcu_flavor(rsp) {
127 seq_printf(m, "%s:\n", rsp->name);
128 for_each_possible_cpu(cpu)
129 print_one_rcu_data(m, per_cpu_ptr(rsp->rda, cpu));
130 }
131 return 0;
132}
133
134static int rcudata_open(struct inode *inode, struct file *file)
135{
136 return single_open(file, show_rcudata, NULL);
137}
138
139static const struct file_operations rcudata_fops = {
140 .owner = THIS_MODULE,
141 .open = rcudata_open,
142 .read = seq_read,
143 .llseek = seq_lseek,
144 .release = single_release,
145};
146
147static void print_one_rcu_data_csv(struct seq_file *m, struct rcu_data *rdp)
148{
149 if (!rdp->beenonline)
150 return;
151 seq_printf(m, "%d,%s,%lu,%lu,%d,%d",
152 rdp->cpu,
153 cpu_is_offline(rdp->cpu) ? "\"N\"" : "\"Y\"",
154 rdp->completed, rdp->gpnum,
155 rdp->passed_quiesce, rdp->qs_pending);
156 seq_printf(m, ",%d,%llx,%d,%lu",
157 atomic_read(&rdp->dynticks->dynticks),
158 rdp->dynticks->dynticks_nesting,
159 rdp->dynticks->dynticks_nmi_nesting,
160 rdp->dynticks_fqs);
161 seq_printf(m, ",%lu", rdp->offline_fqs);
162 seq_printf(m, ",%ld,%ld,\"%c%c%c%c\"", rdp->qlen_lazy, rdp->qlen,
163 ".N"[rdp->nxttail[RCU_NEXT_READY_TAIL] !=
164 rdp->nxttail[RCU_NEXT_TAIL]],
165 ".R"[rdp->nxttail[RCU_WAIT_TAIL] !=
166 rdp->nxttail[RCU_NEXT_READY_TAIL]],
167 ".W"[rdp->nxttail[RCU_DONE_TAIL] !=
168 rdp->nxttail[RCU_WAIT_TAIL]],
169 ".D"[&rdp->nxtlist != rdp->nxttail[RCU_DONE_TAIL]]);
170#ifdef CONFIG_RCU_BOOST
171 seq_printf(m, ",%d,\"%c\"",
172 per_cpu(rcu_cpu_has_work, rdp->cpu),
173 convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
174 rdp->cpu)));
175#endif /* #ifdef CONFIG_RCU_BOOST */
176 seq_printf(m, ",%ld", rdp->blimit);
177 seq_printf(m, ",%lu,%lu,%lu\n",
178 rdp->n_cbs_invoked, rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
179}
180
181static int show_rcudata_csv(struct seq_file *m, void *unused)
182{
183 int cpu;
184 struct rcu_state *rsp;
185
186 seq_puts(m, "\"CPU\",\"Online?\",\"c\",\"g\",\"pq\",\"pq\",");
187 seq_puts(m, "\"dt\",\"dt nesting\",\"dt NMI nesting\",\"df\",");
188 seq_puts(m, "\"of\",\"qll\",\"ql\",\"qs\"");
189#ifdef CONFIG_RCU_BOOST
190 seq_puts(m, "\"kt\",\"ktl\"");
191#endif /* #ifdef CONFIG_RCU_BOOST */
192 seq_puts(m, ",\"b\",\"ci\",\"co\",\"ca\"\n");
193 for_each_rcu_flavor(rsp) {
194 seq_printf(m, "\"%s:\"\n", rsp->name);
195 for_each_possible_cpu(cpu)
196 print_one_rcu_data_csv(m, per_cpu_ptr(rsp->rda, cpu));
197 }
198 return 0;
199}
200
201static int rcudata_csv_open(struct inode *inode, struct file *file)
202{
203 return single_open(file, show_rcudata_csv, NULL);
204}
205
206static const struct file_operations rcudata_csv_fops = {
207 .owner = THIS_MODULE,
208 .open = rcudata_csv_open,
209 .read = seq_read,
210 .llseek = seq_lseek,
211 .release = single_release,
212};
213
214#ifdef CONFIG_RCU_BOOST
215
216static void print_one_rcu_node_boost(struct seq_file *m, struct rcu_node *rnp)
217{
218 seq_printf(m, "%d:%d tasks=%c%c%c%c kt=%c ntb=%lu neb=%lu nnb=%lu ",
219 rnp->grplo, rnp->grphi,
220 "T."[list_empty(&rnp->blkd_tasks)],
221 "N."[!rnp->gp_tasks],
222 "E."[!rnp->exp_tasks],
223 "B."[!rnp->boost_tasks],
224 convert_kthread_status(rnp->boost_kthread_status),
225 rnp->n_tasks_boosted, rnp->n_exp_boosts,
226 rnp->n_normal_boosts);
227 seq_printf(m, "j=%04x bt=%04x\n",
228 (int)(jiffies & 0xffff),
229 (int)(rnp->boost_time & 0xffff));
230 seq_printf(m, " balk: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n",
231 rnp->n_balk_blkd_tasks,
232 rnp->n_balk_exp_gp_tasks,
233 rnp->n_balk_boost_tasks,
234 rnp->n_balk_notblocked,
235 rnp->n_balk_notyet,
236 rnp->n_balk_nos);
237}
238
239static int show_rcu_node_boost(struct seq_file *m, void *unused)
240{
241 struct rcu_node *rnp;
242
243 rcu_for_each_leaf_node(&rcu_preempt_state, rnp)
244 print_one_rcu_node_boost(m, rnp);
245 return 0;
246}
247
248static int rcu_node_boost_open(struct inode *inode, struct file *file)
249{
250 return single_open(file, show_rcu_node_boost, NULL);
251}
252
253static const struct file_operations rcu_node_boost_fops = {
254 .owner = THIS_MODULE,
255 .open = rcu_node_boost_open,
256 .read = seq_read,
257 .llseek = seq_lseek,
258 .release = single_release,
259};
260
261/*
262 * Create the rcuboost debugfs entry. Standard error return.
263 */
264static int rcu_boost_trace_create_file(struct dentry *rcudir)
265{
266 return !debugfs_create_file("rcuboost", 0444, rcudir, NULL,
267 &rcu_node_boost_fops);
268}
269
270#else /* #ifdef CONFIG_RCU_BOOST */
271
272static int rcu_boost_trace_create_file(struct dentry *rcudir)
273{
274 return 0; /* There cannot be an error if we didn't create it! */
275}
276
277#endif /* #else #ifdef CONFIG_RCU_BOOST */
278
279static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
280{
281 unsigned long gpnum;
282 int level = 0;
283 struct rcu_node *rnp;
284
285 gpnum = rsp->gpnum;
286 seq_printf(m, "%s: c=%lu g=%lu s=%d jfq=%ld j=%x ",
287 rsp->name, rsp->completed, gpnum, rsp->fqs_state,
288 (long)(rsp->jiffies_force_qs - jiffies),
289 (int)(jiffies & 0xffff));
290 seq_printf(m, "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld/%ld\n",
291 rsp->n_force_qs, rsp->n_force_qs_ngp,
292 rsp->n_force_qs - rsp->n_force_qs_ngp,
293 rsp->n_force_qs_lh, rsp->qlen_lazy, rsp->qlen);
294 for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_nodes; rnp++) {
295 if (rnp->level != level) {
296 seq_puts(m, "\n");
297 level = rnp->level;
298 }
299 seq_printf(m, "%lx/%lx %c%c>%c %d:%d ^%d ",
300 rnp->qsmask, rnp->qsmaskinit,
301 ".G"[rnp->gp_tasks != NULL],
302 ".E"[rnp->exp_tasks != NULL],
303 ".T"[!list_empty(&rnp->blkd_tasks)],
304 rnp->grplo, rnp->grphi, rnp->grpnum);
305 }
306 seq_puts(m, "\n");
307}
308
309static int show_rcuhier(struct seq_file *m, void *unused)
310{
311 struct rcu_state *rsp;
312
313 for_each_rcu_flavor(rsp)
314 print_one_rcu_state(m, rsp);
315 return 0;
316}
317
318static int rcuhier_open(struct inode *inode, struct file *file)
319{
320 return single_open(file, show_rcuhier, NULL);
321}
322
323static const struct file_operations rcuhier_fops = {
324 .owner = THIS_MODULE,
325 .open = rcuhier_open,
326 .read = seq_read,
327 .llseek = seq_lseek,
328 .release = single_release,
329};
330
331static void show_one_rcugp(struct seq_file *m, struct rcu_state *rsp)
332{
333 unsigned long flags;
334 unsigned long completed;
335 unsigned long gpnum;
336 unsigned long gpage;
337 unsigned long gpmax;
338 struct rcu_node *rnp = &rsp->node[0];
339
340 raw_spin_lock_irqsave(&rnp->lock, flags);
341 completed = rsp->completed;
342 gpnum = rsp->gpnum;
343 if (rsp->completed == rsp->gpnum)
344 gpage = 0;
345 else
346 gpage = jiffies - rsp->gp_start;
347 gpmax = rsp->gp_max;
348 raw_spin_unlock_irqrestore(&rnp->lock, flags);
349 seq_printf(m, "%s: completed=%ld gpnum=%lu age=%ld max=%ld\n",
350 rsp->name, completed, gpnum, gpage, gpmax);
351}
352
353static int show_rcugp(struct seq_file *m, void *unused)
354{
355 struct rcu_state *rsp;
356
357 for_each_rcu_flavor(rsp)
358 show_one_rcugp(m, rsp);
359 return 0;
360}
361
362static int rcugp_open(struct inode *inode, struct file *file)
363{
364 return single_open(file, show_rcugp, NULL);
365}
366
367static const struct file_operations rcugp_fops = {
368 .owner = THIS_MODULE,
369 .open = rcugp_open,
370 .read = seq_read,
371 .llseek = seq_lseek,
372 .release = single_release,
373};
374
375static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
376{
377 seq_printf(m, "%3d%cnp=%ld ",
378 rdp->cpu,
379 cpu_is_offline(rdp->cpu) ? '!' : ' ',
380 rdp->n_rcu_pending);
381 seq_printf(m, "qsp=%ld rpq=%ld cbr=%ld cng=%ld ",
382 rdp->n_rp_qs_pending,
383 rdp->n_rp_report_qs,
384 rdp->n_rp_cb_ready,
385 rdp->n_rp_cpu_needs_gp);
386 seq_printf(m, "gpc=%ld gps=%ld nn=%ld\n",
387 rdp->n_rp_gp_completed,
388 rdp->n_rp_gp_started,
389 rdp->n_rp_need_nothing);
390}
391
392static int show_rcu_pending(struct seq_file *m, void *unused)
393{
394 int cpu;
395 struct rcu_data *rdp;
396 struct rcu_state *rsp;
397
398 for_each_rcu_flavor(rsp) {
399 seq_printf(m, "%s:\n", rsp->name);
400 for_each_possible_cpu(cpu) {
401 rdp = per_cpu_ptr(rsp->rda, cpu);
402 if (rdp->beenonline)
403 print_one_rcu_pending(m, rdp);
404 }
405 }
406 return 0;
407}
408
409static int rcu_pending_open(struct inode *inode, struct file *file)
410{
411 return single_open(file, show_rcu_pending, NULL);
412}
413
414static const struct file_operations rcu_pending_fops = {
415 .owner = THIS_MODULE,
416 .open = rcu_pending_open,
417 .read = seq_read,
418 .llseek = seq_lseek,
419 .release = single_release,
420};
421
422static int show_rcutorture(struct seq_file *m, void *unused)
423{
424 seq_printf(m, "rcutorture test sequence: %lu %s\n",
425 rcutorture_testseq >> 1,
426 (rcutorture_testseq & 0x1) ? "(test in progress)" : "");
427 seq_printf(m, "rcutorture update version number: %lu\n",
428 rcutorture_vernum);
429 return 0;
430}
431
432static int rcutorture_open(struct inode *inode, struct file *file)
433{
434 return single_open(file, show_rcutorture, NULL);
435}
436
437static const struct file_operations rcutorture_fops = {
438 .owner = THIS_MODULE,
439 .open = rcutorture_open,
440 .read = seq_read,
441 .llseek = seq_lseek,
442 .release = single_release,
443};
444
445static struct dentry *rcudir;
446
447static int __init rcutree_trace_init(void)
448{
449 struct dentry *retval;
450
451 rcudir = debugfs_create_dir("rcu", NULL);
452 if (!rcudir)
453 goto free_out;
454
455 retval = debugfs_create_file("rcubarrier", 0444, rcudir,
456 NULL, &rcubarrier_fops);
457 if (!retval)
458 goto free_out;
459
460 retval = debugfs_create_file("rcudata", 0444, rcudir,
461 NULL, &rcudata_fops);
462 if (!retval)
463 goto free_out;
464
465 retval = debugfs_create_file("rcudata.csv", 0444, rcudir,
466 NULL, &rcudata_csv_fops);
467 if (!retval)
468 goto free_out;
469
470 if (rcu_boost_trace_create_file(rcudir))
471 goto free_out;
472
473 retval = debugfs_create_file("rcugp", 0444, rcudir, NULL, &rcugp_fops);
474 if (!retval)
475 goto free_out;
476
477 retval = debugfs_create_file("rcuhier", 0444, rcudir,
478 NULL, &rcuhier_fops);
479 if (!retval)
480 goto free_out;
481
482 retval = debugfs_create_file("rcu_pending", 0444, rcudir,
483 NULL, &rcu_pending_fops);
484 if (!retval)
485 goto free_out;
486
487 retval = debugfs_create_file("rcutorture", 0444, rcudir,
488 NULL, &rcutorture_fops);
489 if (!retval)
490 goto free_out;
491 return 0;
492free_out:
493 debugfs_remove_recursive(rcudir);
494 return 1;
495}
496
497static void __exit rcutree_trace_cleanup(void)
498{
499 debugfs_remove_recursive(rcudir);
500}
501
502
503module_init(rcutree_trace_init);
504module_exit(rcutree_trace_cleanup);
505
506MODULE_AUTHOR("Paul E. McKenney");
507MODULE_DESCRIPTION("Read-Copy Update tracing for hierarchical implementation");
508MODULE_LICENSE("GPL");