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authorPaul E. McKenney <paulmck@linux.vnet.ibm.com>2017-05-15 18:30:32 -0400
committerPaul E. McKenney <paulmck@linux.vnet.ibm.com>2017-06-08 21:52:43 -0400
commitae91aa0adb14dc33114d566feca2f7cb7a96b8b7 (patch)
treed52dfad4c7c9be2acac7c8f0c6890acd38547d60 /kernel/rcu/tree_trace.c
parentbd8cc5a062f41e334596edbe823e2fa0adddd1b7 (diff)
rcu: Remove debugfs tracing
RCU's debugfs tracing used to be the only reasonable low-level debug information available, but ftrace and event tracing has since surpassed the RCU debugfs level of usefulness. This commit therefore removes RCU's debugfs tracing. Signed-off-by: Paul E. McKenney <paulmck@linux.vnet.ibm.com>
Diffstat (limited to 'kernel/rcu/tree_trace.c')
-rw-r--r--kernel/rcu/tree_trace.c494
1 files changed, 0 insertions, 494 deletions
diff --git a/kernel/rcu/tree_trace.c b/kernel/rcu/tree_trace.c
deleted file mode 100644
index 6cea17a1ea30..000000000000
--- a/kernel/rcu/tree_trace.c
+++ /dev/null
@@ -1,494 +0,0 @@
1/*
2 * Read-Copy Update tracing for hierarchical 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, you can access it online at
16 * http://www.gnu.org/licenses/gpl-2.0.html.
17 *
18 * Copyright IBM Corporation, 2008
19 * Author: Paul E. McKenney
20 *
21 * Papers: http://www.rdrop.com/users/paulmck/RCU
22 *
23 * For detailed explanation of Read-Copy Update mechanism see -
24 * Documentation/RCU
25 *
26 */
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#include <linux/prefetch.h>
45
46#define RCU_TREE_NONCORE
47#include "tree.h"
48#include "rcu.h"
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 /* #ifdef CONFIG_RCU_BOOST */
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(rdp->dynticks->rcu_qs_ctr, rdp->cpu),
125 rdp->core_needs_qs);
126 seq_printf(m, " dt=%d/%llx/%d df=%lu",
127 rcu_dynticks_snap(rdp->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 += rcu_segcblist_n_lazy_cbs(&rdp->cblist);
134 ql += rcu_segcblist_n_cbs(&rdp->cblist);
135 seq_printf(m, " ql=%ld/%ld qs=%c%c%c%c",
136 qll, ql,
137 ".N"[!rcu_segcblist_segempty(&rdp->cblist, RCU_NEXT_TAIL)],
138 ".R"[!rcu_segcblist_segempty(&rdp->cblist,
139 RCU_NEXT_READY_TAIL)],
140 ".W"[!rcu_segcblist_segempty(&rdp->cblist, RCU_WAIT_TAIL)],
141 ".D"[!rcu_segcblist_segempty(&rdp->cblist, RCU_DONE_TAIL)]);
142#ifdef CONFIG_RCU_BOOST
143 seq_printf(m, " kt=%d/%c ktl=%x",
144 per_cpu(rcu_cpu_has_work, rdp->cpu),
145 convert_kthread_status(per_cpu(rcu_cpu_kthread_status,
146 rdp->cpu)),
147 per_cpu(rcu_cpu_kthread_loops, rdp->cpu) & 0xffff);
148#endif /* #ifdef CONFIG_RCU_BOOST */
149 seq_printf(m, " b=%ld", rdp->blimit);
150 seq_printf(m, " ci=%lu nci=%lu co=%lu ca=%lu\n",
151 rdp->n_cbs_invoked, rdp->n_nocbs_invoked,
152 rdp->n_cbs_orphaned, rdp->n_cbs_adopted);
153}
154
155static int show_rcudata(struct seq_file *m, void *v)
156{
157 print_one_rcu_data(m, (struct rcu_data *)v);
158 return 0;
159}
160
161static const struct seq_operations rcudate_op = {
162 .start = r_start,
163 .next = r_next,
164 .stop = r_stop,
165 .show = show_rcudata,
166};
167
168static int rcudata_open(struct inode *inode, struct file *file)
169{
170 return r_open(inode, file, &rcudate_op);
171}
172
173static const struct file_operations rcudata_fops = {
174 .owner = THIS_MODULE,
175 .open = rcudata_open,
176 .read = seq_read,
177 .llseek = no_llseek,
178 .release = seq_release,
179};
180
181static int show_rcuexp(struct seq_file *m, void *v)
182{
183 int cpu;
184 struct rcu_state *rsp = (struct rcu_state *)m->private;
185 struct rcu_data *rdp;
186 unsigned long s0 = 0, s1 = 0, s2 = 0, s3 = 0;
187
188 for_each_possible_cpu(cpu) {
189 rdp = per_cpu_ptr(rsp->rda, cpu);
190 s0 += atomic_long_read(&rdp->exp_workdone0);
191 s1 += atomic_long_read(&rdp->exp_workdone1);
192 s2 += atomic_long_read(&rdp->exp_workdone2);
193 s3 += atomic_long_read(&rdp->exp_workdone3);
194 }
195 seq_printf(m, "s=%lu wd0=%lu wd1=%lu wd2=%lu wd3=%lu enq=%d sc=%lu\n",
196 rsp->expedited_sequence, s0, s1, s2, s3,
197 atomic_read(&rsp->expedited_need_qs),
198 rsp->expedited_sequence / 2);
199 return 0;
200}
201
202static int rcuexp_open(struct inode *inode, struct file *file)
203{
204 return single_open(file, show_rcuexp, inode->i_private);
205}
206
207static const struct file_operations rcuexp_fops = {
208 .owner = THIS_MODULE,
209 .open = rcuexp_open,
210 .read = seq_read,
211 .llseek = no_llseek,
212 .release = single_release,
213};
214
215#ifdef CONFIG_RCU_BOOST
216
217static void print_one_rcu_node_boost(struct seq_file *m, struct rcu_node *rnp)
218{
219 seq_printf(m, "%d:%d tasks=%c%c%c%c kt=%c ntb=%lu neb=%lu nnb=%lu ",
220 rnp->grplo, rnp->grphi,
221 "T."[list_empty(&rnp->blkd_tasks)],
222 "N."[!rnp->gp_tasks],
223 "E."[!rnp->exp_tasks],
224 "B."[!rnp->boost_tasks],
225 convert_kthread_status(rnp->boost_kthread_status),
226 rnp->n_tasks_boosted, rnp->n_exp_boosts,
227 rnp->n_normal_boosts);
228 seq_printf(m, "j=%04x bt=%04x\n",
229 (int)(jiffies & 0xffff),
230 (int)(rnp->boost_time & 0xffff));
231 seq_printf(m, " balk: nt=%lu egt=%lu bt=%lu nb=%lu ny=%lu nos=%lu\n",
232 rnp->n_balk_blkd_tasks,
233 rnp->n_balk_exp_gp_tasks,
234 rnp->n_balk_boost_tasks,
235 rnp->n_balk_notblocked,
236 rnp->n_balk_notyet,
237 rnp->n_balk_nos);
238}
239
240static int show_rcu_node_boost(struct seq_file *m, void *unused)
241{
242 struct rcu_node *rnp;
243
244 rcu_for_each_leaf_node(&rcu_preempt_state, rnp)
245 print_one_rcu_node_boost(m, rnp);
246 return 0;
247}
248
249static int rcu_node_boost_open(struct inode *inode, struct file *file)
250{
251 return single_open(file, show_rcu_node_boost, NULL);
252}
253
254static const struct file_operations rcu_node_boost_fops = {
255 .owner = THIS_MODULE,
256 .open = rcu_node_boost_open,
257 .read = seq_read,
258 .llseek = no_llseek,
259 .release = single_release,
260};
261
262#endif /* #ifdef CONFIG_RCU_BOOST */
263
264static void print_one_rcu_state(struct seq_file *m, struct rcu_state *rsp)
265{
266 unsigned long gpnum;
267 int level = 0;
268 struct rcu_node *rnp;
269
270 gpnum = rsp->gpnum;
271 seq_printf(m, "c=%ld g=%ld s=%d jfq=%ld j=%x ",
272 ulong2long(rsp->completed), ulong2long(gpnum),
273 rsp->gp_state,
274 (long)(rsp->jiffies_force_qs - jiffies),
275 (int)(jiffies & 0xffff));
276 seq_printf(m, "nfqs=%lu/nfqsng=%lu(%lu) fqlh=%lu oqlen=%ld/%ld\n",
277 rsp->n_force_qs, rsp->n_force_qs_ngp,
278 rsp->n_force_qs - rsp->n_force_qs_ngp,
279 READ_ONCE(rsp->n_force_qs_lh),
280 rsp->orphan_done.len_lazy,
281 rsp->orphan_done.len);
282 for (rnp = &rsp->node[0]; rnp - &rsp->node[0] < rcu_num_nodes; rnp++) {
283 if (rnp->level != level) {
284 seq_puts(m, "\n");
285 level = rnp->level;
286 }
287 seq_printf(m, "%lx/%lx->%lx %c%c>%c %d:%d ^%d ",
288 rnp->qsmask, rnp->qsmaskinit, rnp->qsmaskinitnext,
289 ".G"[rnp->gp_tasks != NULL],
290 ".E"[rnp->exp_tasks != NULL],
291 ".T"[!list_empty(&rnp->blkd_tasks)],
292 rnp->grplo, rnp->grphi, rnp->grpnum);
293 }
294 seq_puts(m, "\n");
295}
296
297static int show_rcuhier(struct seq_file *m, void *v)
298{
299 struct rcu_state *rsp = (struct rcu_state *)m->private;
300 print_one_rcu_state(m, rsp);
301 return 0;
302}
303
304static int rcuhier_open(struct inode *inode, struct file *file)
305{
306 return single_open(file, show_rcuhier, inode->i_private);
307}
308
309static const struct file_operations rcuhier_fops = {
310 .owner = THIS_MODULE,
311 .open = rcuhier_open,
312 .read = seq_read,
313 .llseek = no_llseek,
314 .release = single_release,
315};
316
317static void show_one_rcugp(struct seq_file *m, struct rcu_state *rsp)
318{
319 unsigned long flags;
320 unsigned long completed;
321 unsigned long gpnum;
322 unsigned long gpage;
323 unsigned long gpmax;
324 struct rcu_node *rnp = &rsp->node[0];
325
326 raw_spin_lock_irqsave_rcu_node(rnp, flags);
327 completed = READ_ONCE(rsp->completed);
328 gpnum = READ_ONCE(rsp->gpnum);
329 if (completed == gpnum)
330 gpage = 0;
331 else
332 gpage = jiffies - rsp->gp_start;
333 gpmax = rsp->gp_max;
334 raw_spin_unlock_irqrestore(&rnp->lock, flags);
335 seq_printf(m, "completed=%ld gpnum=%ld age=%ld max=%ld\n",
336 ulong2long(completed), ulong2long(gpnum), gpage, gpmax);
337}
338
339static int show_rcugp(struct seq_file *m, void *v)
340{
341 struct rcu_state *rsp = (struct rcu_state *)m->private;
342 show_one_rcugp(m, rsp);
343 return 0;
344}
345
346static int rcugp_open(struct inode *inode, struct file *file)
347{
348 return single_open(file, show_rcugp, inode->i_private);
349}
350
351static const struct file_operations rcugp_fops = {
352 .owner = THIS_MODULE,
353 .open = rcugp_open,
354 .read = seq_read,
355 .llseek = no_llseek,
356 .release = single_release,
357};
358
359static void print_one_rcu_pending(struct seq_file *m, struct rcu_data *rdp)
360{
361 if (!rdp->beenonline)
362 return;
363 seq_printf(m, "%3d%cnp=%ld ",
364 rdp->cpu,
365 cpu_is_offline(rdp->cpu) ? '!' : ' ',
366 rdp->n_rcu_pending);
367 seq_printf(m, "qsp=%ld rpq=%ld cbr=%ld cng=%ld ",
368 rdp->n_rp_core_needs_qs,
369 rdp->n_rp_report_qs,
370 rdp->n_rp_cb_ready,
371 rdp->n_rp_cpu_needs_gp);
372 seq_printf(m, "gpc=%ld gps=%ld nn=%ld ndw%ld\n",
373 rdp->n_rp_gp_completed,
374 rdp->n_rp_gp_started,
375 rdp->n_rp_nocb_defer_wakeup,
376 rdp->n_rp_need_nothing);
377}
378
379static int show_rcu_pending(struct seq_file *m, void *v)
380{
381 print_one_rcu_pending(m, (struct rcu_data *)v);
382 return 0;
383}
384
385static const struct seq_operations rcu_pending_op = {
386 .start = r_start,
387 .next = r_next,
388 .stop = r_stop,
389 .show = show_rcu_pending,
390};
391
392static int rcu_pending_open(struct inode *inode, struct file *file)
393{
394 return r_open(inode, file, &rcu_pending_op);
395}
396
397static const struct file_operations rcu_pending_fops = {
398 .owner = THIS_MODULE,
399 .open = rcu_pending_open,
400 .read = seq_read,
401 .llseek = no_llseek,
402 .release = seq_release,
403};
404
405static int show_rcutorture(struct seq_file *m, void *unused)
406{
407 seq_printf(m, "rcutorture test sequence: %lu %s\n",
408 rcutorture_testseq >> 1,
409 (rcutorture_testseq & 0x1) ? "(test in progress)" : "");
410 seq_printf(m, "rcutorture update version number: %lu\n",
411 rcutorture_vernum);
412 return 0;
413}
414
415static int rcutorture_open(struct inode *inode, struct file *file)
416{
417 return single_open(file, show_rcutorture, NULL);
418}
419
420static const struct file_operations rcutorture_fops = {
421 .owner = THIS_MODULE,
422 .open = rcutorture_open,
423 .read = seq_read,
424 .llseek = seq_lseek,
425 .release = single_release,
426};
427
428static struct dentry *rcudir;
429
430static int __init rcutree_trace_init(void)
431{
432 struct rcu_state *rsp;
433 struct dentry *retval;
434 struct dentry *rspdir;
435
436 rcudir = debugfs_create_dir("rcu", NULL);
437 if (!rcudir)
438 goto free_out;
439
440 for_each_rcu_flavor(rsp) {
441 rspdir = debugfs_create_dir(rsp->name, rcudir);
442 if (!rspdir)
443 goto free_out;
444
445 retval = debugfs_create_file("rcudata", 0444,
446 rspdir, rsp, &rcudata_fops);
447 if (!retval)
448 goto free_out;
449
450 retval = debugfs_create_file("rcuexp", 0444,
451 rspdir, rsp, &rcuexp_fops);
452 if (!retval)
453 goto free_out;
454
455 retval = debugfs_create_file("rcu_pending", 0444,
456 rspdir, rsp, &rcu_pending_fops);
457 if (!retval)
458 goto free_out;
459
460 retval = debugfs_create_file("rcubarrier", 0444,
461 rspdir, rsp, &rcubarrier_fops);
462 if (!retval)
463 goto free_out;
464
465#ifdef CONFIG_RCU_BOOST
466 if (rsp == &rcu_preempt_state) {
467 retval = debugfs_create_file("rcuboost", 0444,
468 rspdir, NULL, &rcu_node_boost_fops);
469 if (!retval)
470 goto free_out;
471 }
472#endif
473
474 retval = debugfs_create_file("rcugp", 0444,
475 rspdir, rsp, &rcugp_fops);
476 if (!retval)
477 goto free_out;
478
479 retval = debugfs_create_file("rcuhier", 0444,
480 rspdir, rsp, &rcuhier_fops);
481 if (!retval)
482 goto free_out;
483 }
484
485 retval = debugfs_create_file("rcutorture", 0444, rcudir,
486 NULL, &rcutorture_fops);
487 if (!retval)
488 goto free_out;
489 return 0;
490free_out:
491 debugfs_remove_recursive(rcudir);
492 return 1;
493}
494device_initcall(rcutree_trace_init);
generated by cgit v1.2.2 (git 2.25.0) at 2025-09-21 02:38:53 -0400