Merge remote branch 'nouveau/drm-nouveau-next' of /ssd/git/drm-nouveau-next into...
[pandora-kernel.git] / kernel / lockdep_proc.c
1 /*
2  * kernel/lockdep_proc.c
3  *
4  * Runtime locking correctness validator
5  *
6  * Started by Ingo Molnar:
7  *
8  *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
9  *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
10  *
11  * Code for /proc/lockdep and /proc/lockdep_stats:
12  *
13  */
14 #include <linux/module.h>
15 #include <linux/proc_fs.h>
16 #include <linux/seq_file.h>
17 #include <linux/kallsyms.h>
18 #include <linux/debug_locks.h>
19 #include <linux/vmalloc.h>
20 #include <linux/sort.h>
21 #include <asm/uaccess.h>
22 #include <asm/div64.h>
23
24 #include "lockdep_internals.h"
25
26 static void *l_next(struct seq_file *m, void *v, loff_t *pos)
27 {
28         return seq_list_next(v, &all_lock_classes, pos);
29 }
30
31 static void *l_start(struct seq_file *m, loff_t *pos)
32 {
33         return seq_list_start_head(&all_lock_classes, *pos);
34 }
35
36 static void l_stop(struct seq_file *m, void *v)
37 {
38 }
39
40 static void print_name(struct seq_file *m, struct lock_class *class)
41 {
42         char str[128];
43         const char *name = class->name;
44
45         if (!name) {
46                 name = __get_key_name(class->key, str);
47                 seq_printf(m, "%s", name);
48         } else{
49                 seq_printf(m, "%s", name);
50                 if (class->name_version > 1)
51                         seq_printf(m, "#%d", class->name_version);
52                 if (class->subclass)
53                         seq_printf(m, "/%d", class->subclass);
54         }
55 }
56
57 static int l_show(struct seq_file *m, void *v)
58 {
59         struct lock_class *class = list_entry(v, struct lock_class, lock_entry);
60         struct lock_list *entry;
61         char usage[LOCK_USAGE_CHARS];
62
63         if (v == &all_lock_classes) {
64                 seq_printf(m, "all lock classes:\n");
65                 return 0;
66         }
67
68         seq_printf(m, "%p", class->key);
69 #ifdef CONFIG_DEBUG_LOCKDEP
70         seq_printf(m, " OPS:%8ld", class->ops);
71 #endif
72 #ifdef CONFIG_PROVE_LOCKING
73         seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class));
74         seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class));
75 #endif
76
77         get_usage_chars(class, usage);
78         seq_printf(m, " %s", usage);
79
80         seq_printf(m, ": ");
81         print_name(m, class);
82         seq_puts(m, "\n");
83
84         list_for_each_entry(entry, &class->locks_after, entry) {
85                 if (entry->distance == 1) {
86                         seq_printf(m, " -> [%p] ", entry->class->key);
87                         print_name(m, entry->class);
88                         seq_puts(m, "\n");
89                 }
90         }
91         seq_puts(m, "\n");
92
93         return 0;
94 }
95
96 static const struct seq_operations lockdep_ops = {
97         .start  = l_start,
98         .next   = l_next,
99         .stop   = l_stop,
100         .show   = l_show,
101 };
102
103 static int lockdep_open(struct inode *inode, struct file *file)
104 {
105         return seq_open(file, &lockdep_ops);
106 }
107
108 static const struct file_operations proc_lockdep_operations = {
109         .open           = lockdep_open,
110         .read           = seq_read,
111         .llseek         = seq_lseek,
112         .release        = seq_release,
113 };
114
115 #ifdef CONFIG_PROVE_LOCKING
116 static void *lc_start(struct seq_file *m, loff_t *pos)
117 {
118         if (*pos == 0)
119                 return SEQ_START_TOKEN;
120
121         if (*pos - 1 < nr_lock_chains)
122                 return lock_chains + (*pos - 1);
123
124         return NULL;
125 }
126
127 static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
128 {
129         (*pos)++;
130         return lc_start(m, pos);
131 }
132
133 static void lc_stop(struct seq_file *m, void *v)
134 {
135 }
136
137 static int lc_show(struct seq_file *m, void *v)
138 {
139         struct lock_chain *chain = v;
140         struct lock_class *class;
141         int i;
142
143         if (v == SEQ_START_TOKEN) {
144                 seq_printf(m, "all lock chains:\n");
145                 return 0;
146         }
147
148         seq_printf(m, "irq_context: %d\n", chain->irq_context);
149
150         for (i = 0; i < chain->depth; i++) {
151                 class = lock_chain_get_class(chain, i);
152                 if (!class->key)
153                         continue;
154
155                 seq_printf(m, "[%p] ", class->key);
156                 print_name(m, class);
157                 seq_puts(m, "\n");
158         }
159         seq_puts(m, "\n");
160
161         return 0;
162 }
163
164 static const struct seq_operations lockdep_chains_ops = {
165         .start  = lc_start,
166         .next   = lc_next,
167         .stop   = lc_stop,
168         .show   = lc_show,
169 };
170
171 static int lockdep_chains_open(struct inode *inode, struct file *file)
172 {
173         return seq_open(file, &lockdep_chains_ops);
174 }
175
176 static const struct file_operations proc_lockdep_chains_operations = {
177         .open           = lockdep_chains_open,
178         .read           = seq_read,
179         .llseek         = seq_lseek,
180         .release        = seq_release,
181 };
182 #endif /* CONFIG_PROVE_LOCKING */
183
184 static void lockdep_stats_debug_show(struct seq_file *m)
185 {
186 #ifdef CONFIG_DEBUG_LOCKDEP
187         unsigned long long hi1 = debug_atomic_read(hardirqs_on_events),
188                            hi2 = debug_atomic_read(hardirqs_off_events),
189                            hr1 = debug_atomic_read(redundant_hardirqs_on),
190                            hr2 = debug_atomic_read(redundant_hardirqs_off),
191                            si1 = debug_atomic_read(softirqs_on_events),
192                            si2 = debug_atomic_read(softirqs_off_events),
193                            sr1 = debug_atomic_read(redundant_softirqs_on),
194                            sr2 = debug_atomic_read(redundant_softirqs_off);
195
196         seq_printf(m, " chain lookup misses:           %11llu\n",
197                 debug_atomic_read(chain_lookup_misses));
198         seq_printf(m, " chain lookup hits:             %11llu\n",
199                 debug_atomic_read(chain_lookup_hits));
200         seq_printf(m, " cyclic checks:                 %11llu\n",
201                 debug_atomic_read(nr_cyclic_checks));
202         seq_printf(m, " find-mask forwards checks:     %11llu\n",
203                 debug_atomic_read(nr_find_usage_forwards_checks));
204         seq_printf(m, " find-mask backwards checks:    %11llu\n",
205                 debug_atomic_read(nr_find_usage_backwards_checks));
206
207         seq_printf(m, " hardirq on events:             %11llu\n", hi1);
208         seq_printf(m, " hardirq off events:            %11llu\n", hi2);
209         seq_printf(m, " redundant hardirq ons:         %11llu\n", hr1);
210         seq_printf(m, " redundant hardirq offs:        %11llu\n", hr2);
211         seq_printf(m, " softirq on events:             %11llu\n", si1);
212         seq_printf(m, " softirq off events:            %11llu\n", si2);
213         seq_printf(m, " redundant softirq ons:         %11llu\n", sr1);
214         seq_printf(m, " redundant softirq offs:        %11llu\n", sr2);
215 #endif
216 }
217
218 static int lockdep_stats_show(struct seq_file *m, void *v)
219 {
220         struct lock_class *class;
221         unsigned long nr_unused = 0, nr_uncategorized = 0,
222                       nr_irq_safe = 0, nr_irq_unsafe = 0,
223                       nr_softirq_safe = 0, nr_softirq_unsafe = 0,
224                       nr_hardirq_safe = 0, nr_hardirq_unsafe = 0,
225                       nr_irq_read_safe = 0, nr_irq_read_unsafe = 0,
226                       nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0,
227                       nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,
228                       sum_forward_deps = 0, factor = 0;
229
230         list_for_each_entry(class, &all_lock_classes, lock_entry) {
231
232                 if (class->usage_mask == 0)
233                         nr_unused++;
234                 if (class->usage_mask == LOCKF_USED)
235                         nr_uncategorized++;
236                 if (class->usage_mask & LOCKF_USED_IN_IRQ)
237                         nr_irq_safe++;
238                 if (class->usage_mask & LOCKF_ENABLED_IRQ)
239                         nr_irq_unsafe++;
240                 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
241                         nr_softirq_safe++;
242                 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ)
243                         nr_softirq_unsafe++;
244                 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
245                         nr_hardirq_safe++;
246                 if (class->usage_mask & LOCKF_ENABLED_HARDIRQ)
247                         nr_hardirq_unsafe++;
248                 if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
249                         nr_irq_read_safe++;
250                 if (class->usage_mask & LOCKF_ENABLED_IRQ_READ)
251                         nr_irq_read_unsafe++;
252                 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
253                         nr_softirq_read_safe++;
254                 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ)
255                         nr_softirq_read_unsafe++;
256                 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
257                         nr_hardirq_read_safe++;
258                 if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ)
259                         nr_hardirq_read_unsafe++;
260
261 #ifdef CONFIG_PROVE_LOCKING
262                 sum_forward_deps += lockdep_count_forward_deps(class);
263 #endif
264         }
265 #ifdef CONFIG_DEBUG_LOCKDEP
266         DEBUG_LOCKS_WARN_ON(debug_atomic_read(nr_unused_locks) != nr_unused);
267 #endif
268         seq_printf(m, " lock-classes:                  %11lu [max: %lu]\n",
269                         nr_lock_classes, MAX_LOCKDEP_KEYS);
270         seq_printf(m, " direct dependencies:           %11lu [max: %lu]\n",
271                         nr_list_entries, MAX_LOCKDEP_ENTRIES);
272         seq_printf(m, " indirect dependencies:         %11lu\n",
273                         sum_forward_deps);
274
275         /*
276          * Total number of dependencies:
277          *
278          * All irq-safe locks may nest inside irq-unsafe locks,
279          * plus all the other known dependencies:
280          */
281         seq_printf(m, " all direct dependencies:       %11lu\n",
282                         nr_irq_unsafe * nr_irq_safe +
283                         nr_hardirq_unsafe * nr_hardirq_safe +
284                         nr_list_entries);
285
286         /*
287          * Estimated factor between direct and indirect
288          * dependencies:
289          */
290         if (nr_list_entries)
291                 factor = sum_forward_deps / nr_list_entries;
292
293 #ifdef CONFIG_PROVE_LOCKING
294         seq_printf(m, " dependency chains:             %11lu [max: %lu]\n",
295                         nr_lock_chains, MAX_LOCKDEP_CHAINS);
296         seq_printf(m, " dependency chain hlocks:       %11d [max: %lu]\n",
297                         nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);
298 #endif
299
300 #ifdef CONFIG_TRACE_IRQFLAGS
301         seq_printf(m, " in-hardirq chains:             %11u\n",
302                         nr_hardirq_chains);
303         seq_printf(m, " in-softirq chains:             %11u\n",
304                         nr_softirq_chains);
305 #endif
306         seq_printf(m, " in-process chains:             %11u\n",
307                         nr_process_chains);
308         seq_printf(m, " stack-trace entries:           %11lu [max: %lu]\n",
309                         nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES);
310         seq_printf(m, " combined max dependencies:     %11u\n",
311                         (nr_hardirq_chains + 1) *
312                         (nr_softirq_chains + 1) *
313                         (nr_process_chains + 1)
314         );
315         seq_printf(m, " hardirq-safe locks:            %11lu\n",
316                         nr_hardirq_safe);
317         seq_printf(m, " hardirq-unsafe locks:          %11lu\n",
318                         nr_hardirq_unsafe);
319         seq_printf(m, " softirq-safe locks:            %11lu\n",
320                         nr_softirq_safe);
321         seq_printf(m, " softirq-unsafe locks:          %11lu\n",
322                         nr_softirq_unsafe);
323         seq_printf(m, " irq-safe locks:                %11lu\n",
324                         nr_irq_safe);
325         seq_printf(m, " irq-unsafe locks:              %11lu\n",
326                         nr_irq_unsafe);
327
328         seq_printf(m, " hardirq-read-safe locks:       %11lu\n",
329                         nr_hardirq_read_safe);
330         seq_printf(m, " hardirq-read-unsafe locks:     %11lu\n",
331                         nr_hardirq_read_unsafe);
332         seq_printf(m, " softirq-read-safe locks:       %11lu\n",
333                         nr_softirq_read_safe);
334         seq_printf(m, " softirq-read-unsafe locks:     %11lu\n",
335                         nr_softirq_read_unsafe);
336         seq_printf(m, " irq-read-safe locks:           %11lu\n",
337                         nr_irq_read_safe);
338         seq_printf(m, " irq-read-unsafe locks:         %11lu\n",
339                         nr_irq_read_unsafe);
340
341         seq_printf(m, " uncategorized locks:           %11lu\n",
342                         nr_uncategorized);
343         seq_printf(m, " unused locks:                  %11lu\n",
344                         nr_unused);
345         seq_printf(m, " max locking depth:             %11u\n",
346                         max_lockdep_depth);
347 #ifdef CONFIG_PROVE_LOCKING
348         seq_printf(m, " max bfs queue depth:           %11u\n",
349                         max_bfs_queue_depth);
350 #endif
351         lockdep_stats_debug_show(m);
352         seq_printf(m, " debug_locks:                   %11u\n",
353                         debug_locks);
354
355         return 0;
356 }
357
358 static int lockdep_stats_open(struct inode *inode, struct file *file)
359 {
360         return single_open(file, lockdep_stats_show, NULL);
361 }
362
363 static const struct file_operations proc_lockdep_stats_operations = {
364         .open           = lockdep_stats_open,
365         .read           = seq_read,
366         .llseek         = seq_lseek,
367         .release        = single_release,
368 };
369
370 #ifdef CONFIG_LOCK_STAT
371
372 struct lock_stat_data {
373         struct lock_class *class;
374         struct lock_class_stats stats;
375 };
376
377 struct lock_stat_seq {
378         struct lock_stat_data *iter_end;
379         struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
380 };
381
382 /*
383  * sort on absolute number of contentions
384  */
385 static int lock_stat_cmp(const void *l, const void *r)
386 {
387         const struct lock_stat_data *dl = l, *dr = r;
388         unsigned long nl, nr;
389
390         nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;
391         nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr;
392
393         return nr - nl;
394 }
395
396 static void seq_line(struct seq_file *m, char c, int offset, int length)
397 {
398         int i;
399
400         for (i = 0; i < offset; i++)
401                 seq_puts(m, " ");
402         for (i = 0; i < length; i++)
403                 seq_printf(m, "%c", c);
404         seq_puts(m, "\n");
405 }
406
407 static void snprint_time(char *buf, size_t bufsiz, s64 nr)
408 {
409         s64 div;
410         s32 rem;
411
412         nr += 5; /* for display rounding */
413         div = div_s64_rem(nr, 1000, &rem);
414         snprintf(buf, bufsiz, "%lld.%02d", (long long)div, (int)rem/10);
415 }
416
417 static void seq_time(struct seq_file *m, s64 time)
418 {
419         char num[15];
420
421         snprint_time(num, sizeof(num), time);
422         seq_printf(m, " %14s", num);
423 }
424
425 static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
426 {
427         seq_printf(m, "%14lu", lt->nr);
428         seq_time(m, lt->min);
429         seq_time(m, lt->max);
430         seq_time(m, lt->total);
431 }
432
433 static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
434 {
435         char name[39];
436         struct lock_class *class;
437         struct lock_class_stats *stats;
438         int i, namelen;
439
440         class = data->class;
441         stats = &data->stats;
442
443         namelen = 38;
444         if (class->name_version > 1)
445                 namelen -= 2; /* XXX truncates versions > 9 */
446         if (class->subclass)
447                 namelen -= 2;
448
449         if (!class->name) {
450                 char str[KSYM_NAME_LEN];
451                 const char *key_name;
452
453                 key_name = __get_key_name(class->key, str);
454                 snprintf(name, namelen, "%s", key_name);
455         } else {
456                 snprintf(name, namelen, "%s", class->name);
457         }
458         namelen = strlen(name);
459         if (class->name_version > 1) {
460                 snprintf(name+namelen, 3, "#%d", class->name_version);
461                 namelen += 2;
462         }
463         if (class->subclass) {
464                 snprintf(name+namelen, 3, "/%d", class->subclass);
465                 namelen += 2;
466         }
467
468         if (stats->write_holdtime.nr) {
469                 if (stats->read_holdtime.nr)
470                         seq_printf(m, "%38s-W:", name);
471                 else
472                         seq_printf(m, "%40s:", name);
473
474                 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);
475                 seq_lock_time(m, &stats->write_waittime);
476                 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);
477                 seq_lock_time(m, &stats->write_holdtime);
478                 seq_puts(m, "\n");
479         }
480
481         if (stats->read_holdtime.nr) {
482                 seq_printf(m, "%38s-R:", name);
483                 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);
484                 seq_lock_time(m, &stats->read_waittime);
485                 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);
486                 seq_lock_time(m, &stats->read_holdtime);
487                 seq_puts(m, "\n");
488         }
489
490         if (stats->read_waittime.nr + stats->write_waittime.nr == 0)
491                 return;
492
493         if (stats->read_holdtime.nr)
494                 namelen += 2;
495
496         for (i = 0; i < LOCKSTAT_POINTS; i++) {
497                 char ip[32];
498
499                 if (class->contention_point[i] == 0)
500                         break;
501
502                 if (!i)
503                         seq_line(m, '-', 40-namelen, namelen);
504
505                 snprintf(ip, sizeof(ip), "[<%p>]",
506                                 (void *)class->contention_point[i]);
507                 seq_printf(m, "%40s %14lu %29s %pS\n",
508                            name, stats->contention_point[i],
509                            ip, (void *)class->contention_point[i]);
510         }
511         for (i = 0; i < LOCKSTAT_POINTS; i++) {
512                 char ip[32];
513
514                 if (class->contending_point[i] == 0)
515                         break;
516
517                 if (!i)
518                         seq_line(m, '-', 40-namelen, namelen);
519
520                 snprintf(ip, sizeof(ip), "[<%p>]",
521                                 (void *)class->contending_point[i]);
522                 seq_printf(m, "%40s %14lu %29s %pS\n",
523                            name, stats->contending_point[i],
524                            ip, (void *)class->contending_point[i]);
525         }
526         if (i) {
527                 seq_puts(m, "\n");
528                 seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
529                 seq_puts(m, "\n");
530         }
531 }
532
533 static void seq_header(struct seq_file *m)
534 {
535         seq_printf(m, "lock_stat version 0.3\n");
536
537         if (unlikely(!debug_locks))
538                 seq_printf(m, "*WARNING* lock debugging disabled!! - possibly due to a lockdep warning\n");
539
540         seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
541         seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
542                         "%14s %14s\n",
543                         "class name",
544                         "con-bounces",
545                         "contentions",
546                         "waittime-min",
547                         "waittime-max",
548                         "waittime-total",
549                         "acq-bounces",
550                         "acquisitions",
551                         "holdtime-min",
552                         "holdtime-max",
553                         "holdtime-total");
554         seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
555         seq_printf(m, "\n");
556 }
557
558 static void *ls_start(struct seq_file *m, loff_t *pos)
559 {
560         struct lock_stat_seq *data = m->private;
561         struct lock_stat_data *iter;
562
563         if (*pos == 0)
564                 return SEQ_START_TOKEN;
565
566         iter = data->stats + (*pos - 1);
567         if (iter >= data->iter_end)
568                 iter = NULL;
569
570         return iter;
571 }
572
573 static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
574 {
575         (*pos)++;
576         return ls_start(m, pos);
577 }
578
579 static void ls_stop(struct seq_file *m, void *v)
580 {
581 }
582
583 static int ls_show(struct seq_file *m, void *v)
584 {
585         if (v == SEQ_START_TOKEN)
586                 seq_header(m);
587         else
588                 seq_stats(m, v);
589
590         return 0;
591 }
592
593 static const struct seq_operations lockstat_ops = {
594         .start  = ls_start,
595         .next   = ls_next,
596         .stop   = ls_stop,
597         .show   = ls_show,
598 };
599
600 static int lock_stat_open(struct inode *inode, struct file *file)
601 {
602         int res;
603         struct lock_class *class;
604         struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));
605
606         if (!data)
607                 return -ENOMEM;
608
609         res = seq_open(file, &lockstat_ops);
610         if (!res) {
611                 struct lock_stat_data *iter = data->stats;
612                 struct seq_file *m = file->private_data;
613
614                 list_for_each_entry(class, &all_lock_classes, lock_entry) {
615                         iter->class = class;
616                         iter->stats = lock_stats(class);
617                         iter++;
618                 }
619                 data->iter_end = iter;
620
621                 sort(data->stats, data->iter_end - data->stats,
622                                 sizeof(struct lock_stat_data),
623                                 lock_stat_cmp, NULL);
624
625                 m->private = data;
626         } else
627                 vfree(data);
628
629         return res;
630 }
631
632 static ssize_t lock_stat_write(struct file *file, const char __user *buf,
633                                size_t count, loff_t *ppos)
634 {
635         struct lock_class *class;
636         char c;
637
638         if (count) {
639                 if (get_user(c, buf))
640                         return -EFAULT;
641
642                 if (c != '0')
643                         return count;
644
645                 list_for_each_entry(class, &all_lock_classes, lock_entry)
646                         clear_lock_stats(class);
647         }
648         return count;
649 }
650
651 static int lock_stat_release(struct inode *inode, struct file *file)
652 {
653         struct seq_file *seq = file->private_data;
654
655         vfree(seq->private);
656         return seq_release(inode, file);
657 }
658
659 static const struct file_operations proc_lock_stat_operations = {
660         .open           = lock_stat_open,
661         .write          = lock_stat_write,
662         .read           = seq_read,
663         .llseek         = seq_lseek,
664         .release        = lock_stat_release,
665 };
666 #endif /* CONFIG_LOCK_STAT */
667
668 static int __init lockdep_proc_init(void)
669 {
670         proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
671 #ifdef CONFIG_PROVE_LOCKING
672         proc_create("lockdep_chains", S_IRUSR, NULL,
673                     &proc_lockdep_chains_operations);
674 #endif
675         proc_create("lockdep_stats", S_IRUSR, NULL,
676                     &proc_lockdep_stats_operations);
677
678 #ifdef CONFIG_LOCK_STAT
679         proc_create("lock_stat", S_IRUSR | S_IWUSR, NULL,
680                     &proc_lock_stat_operations);
681 #endif
682
683         return 0;
684 }
685
686 __initcall(lockdep_proc_init);
687