bootmem: add debugging framework
[linux-2.6/linux-acpi-2.6/ibm-acpi-2.6.git] / kernel / lockdep_proc.c
blob9b0e940e2545efe99012dd1526ef79a4739f02d2
1 /*
2 * kernel/lockdep_proc.c
4 * Runtime locking correctness validator
6 * Started by Ingo Molnar:
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>
11 * Code for /proc/lockdep and /proc/lockdep_stats:
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>
24 #include "lockdep_internals.h"
26 static void *l_next(struct seq_file *m, void *v, loff_t *pos)
28 struct lock_class *class;
30 (*pos)++;
32 if (v == SEQ_START_TOKEN)
33 class = m->private;
34 else {
35 class = v;
37 if (class->lock_entry.next != &all_lock_classes)
38 class = list_entry(class->lock_entry.next,
39 struct lock_class, lock_entry);
40 else
41 class = NULL;
44 return class;
47 static void *l_start(struct seq_file *m, loff_t *pos)
49 struct lock_class *class;
50 loff_t i = 0;
52 if (*pos == 0)
53 return SEQ_START_TOKEN;
55 list_for_each_entry(class, &all_lock_classes, lock_entry) {
56 if (++i == *pos)
57 return class;
59 return NULL;
62 static void l_stop(struct seq_file *m, void *v)
66 static unsigned long count_forward_deps(struct lock_class *class)
68 struct lock_list *entry;
69 unsigned long ret = 1;
72 * Recurse this class's dependency list:
74 list_for_each_entry(entry, &class->locks_after, entry)
75 ret += count_forward_deps(entry->class);
77 return ret;
80 static unsigned long count_backward_deps(struct lock_class *class)
82 struct lock_list *entry;
83 unsigned long ret = 1;
86 * Recurse this class's dependency list:
88 list_for_each_entry(entry, &class->locks_before, entry)
89 ret += count_backward_deps(entry->class);
91 return ret;
94 static void print_name(struct seq_file *m, struct lock_class *class)
96 char str[128];
97 const char *name = class->name;
99 if (!name) {
100 name = __get_key_name(class->key, str);
101 seq_printf(m, "%s", name);
102 } else{
103 seq_printf(m, "%s", name);
104 if (class->name_version > 1)
105 seq_printf(m, "#%d", class->name_version);
106 if (class->subclass)
107 seq_printf(m, "/%d", class->subclass);
111 static int l_show(struct seq_file *m, void *v)
113 unsigned long nr_forward_deps, nr_backward_deps;
114 struct lock_class *class = v;
115 struct lock_list *entry;
116 char c1, c2, c3, c4;
118 if (v == SEQ_START_TOKEN) {
119 seq_printf(m, "all lock classes:\n");
120 return 0;
123 seq_printf(m, "%p", class->key);
124 #ifdef CONFIG_DEBUG_LOCKDEP
125 seq_printf(m, " OPS:%8ld", class->ops);
126 #endif
127 nr_forward_deps = count_forward_deps(class);
128 seq_printf(m, " FD:%5ld", nr_forward_deps);
130 nr_backward_deps = count_backward_deps(class);
131 seq_printf(m, " BD:%5ld", nr_backward_deps);
133 get_usage_chars(class, &c1, &c2, &c3, &c4);
134 seq_printf(m, " %c%c%c%c", c1, c2, c3, c4);
136 seq_printf(m, ": ");
137 print_name(m, class);
138 seq_puts(m, "\n");
140 list_for_each_entry(entry, &class->locks_after, entry) {
141 if (entry->distance == 1) {
142 seq_printf(m, " -> [%p] ", entry->class->key);
143 print_name(m, entry->class);
144 seq_puts(m, "\n");
147 seq_puts(m, "\n");
149 return 0;
152 static const struct seq_operations lockdep_ops = {
153 .start = l_start,
154 .next = l_next,
155 .stop = l_stop,
156 .show = l_show,
159 static int lockdep_open(struct inode *inode, struct file *file)
161 int res = seq_open(file, &lockdep_ops);
162 if (!res) {
163 struct seq_file *m = file->private_data;
165 if (!list_empty(&all_lock_classes))
166 m->private = list_entry(all_lock_classes.next,
167 struct lock_class, lock_entry);
168 else
169 m->private = NULL;
171 return res;
174 static const struct file_operations proc_lockdep_operations = {
175 .open = lockdep_open,
176 .read = seq_read,
177 .llseek = seq_lseek,
178 .release = seq_release,
181 #ifdef CONFIG_PROVE_LOCKING
182 static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
184 struct lock_chain *chain;
186 (*pos)++;
188 if (v == SEQ_START_TOKEN)
189 chain = m->private;
190 else {
191 chain = v;
193 if (*pos < nr_lock_chains)
194 chain = lock_chains + *pos;
195 else
196 chain = NULL;
199 return chain;
202 static void *lc_start(struct seq_file *m, loff_t *pos)
204 if (*pos == 0)
205 return SEQ_START_TOKEN;
207 if (*pos < nr_lock_chains)
208 return lock_chains + *pos;
210 return NULL;
213 static void lc_stop(struct seq_file *m, void *v)
217 static int lc_show(struct seq_file *m, void *v)
219 struct lock_chain *chain = v;
220 struct lock_class *class;
221 int i;
223 if (v == SEQ_START_TOKEN) {
224 seq_printf(m, "all lock chains:\n");
225 return 0;
228 seq_printf(m, "irq_context: %d\n", chain->irq_context);
230 for (i = 0; i < chain->depth; i++) {
231 class = lock_chain_get_class(chain, i);
232 seq_printf(m, "[%p] ", class->key);
233 print_name(m, class);
234 seq_puts(m, "\n");
236 seq_puts(m, "\n");
238 return 0;
241 static const struct seq_operations lockdep_chains_ops = {
242 .start = lc_start,
243 .next = lc_next,
244 .stop = lc_stop,
245 .show = lc_show,
248 static int lockdep_chains_open(struct inode *inode, struct file *file)
250 int res = seq_open(file, &lockdep_chains_ops);
251 if (!res) {
252 struct seq_file *m = file->private_data;
254 if (nr_lock_chains)
255 m->private = lock_chains;
256 else
257 m->private = NULL;
259 return res;
262 static const struct file_operations proc_lockdep_chains_operations = {
263 .open = lockdep_chains_open,
264 .read = seq_read,
265 .llseek = seq_lseek,
266 .release = seq_release,
268 #endif /* CONFIG_PROVE_LOCKING */
270 static void lockdep_stats_debug_show(struct seq_file *m)
272 #ifdef CONFIG_DEBUG_LOCKDEP
273 unsigned int hi1 = debug_atomic_read(&hardirqs_on_events),
274 hi2 = debug_atomic_read(&hardirqs_off_events),
275 hr1 = debug_atomic_read(&redundant_hardirqs_on),
276 hr2 = debug_atomic_read(&redundant_hardirqs_off),
277 si1 = debug_atomic_read(&softirqs_on_events),
278 si2 = debug_atomic_read(&softirqs_off_events),
279 sr1 = debug_atomic_read(&redundant_softirqs_on),
280 sr2 = debug_atomic_read(&redundant_softirqs_off);
282 seq_printf(m, " chain lookup misses: %11u\n",
283 debug_atomic_read(&chain_lookup_misses));
284 seq_printf(m, " chain lookup hits: %11u\n",
285 debug_atomic_read(&chain_lookup_hits));
286 seq_printf(m, " cyclic checks: %11u\n",
287 debug_atomic_read(&nr_cyclic_checks));
288 seq_printf(m, " cyclic-check recursions: %11u\n",
289 debug_atomic_read(&nr_cyclic_check_recursions));
290 seq_printf(m, " find-mask forwards checks: %11u\n",
291 debug_atomic_read(&nr_find_usage_forwards_checks));
292 seq_printf(m, " find-mask forwards recursions: %11u\n",
293 debug_atomic_read(&nr_find_usage_forwards_recursions));
294 seq_printf(m, " find-mask backwards checks: %11u\n",
295 debug_atomic_read(&nr_find_usage_backwards_checks));
296 seq_printf(m, " find-mask backwards recursions:%11u\n",
297 debug_atomic_read(&nr_find_usage_backwards_recursions));
299 seq_printf(m, " hardirq on events: %11u\n", hi1);
300 seq_printf(m, " hardirq off events: %11u\n", hi2);
301 seq_printf(m, " redundant hardirq ons: %11u\n", hr1);
302 seq_printf(m, " redundant hardirq offs: %11u\n", hr2);
303 seq_printf(m, " softirq on events: %11u\n", si1);
304 seq_printf(m, " softirq off events: %11u\n", si2);
305 seq_printf(m, " redundant softirq ons: %11u\n", sr1);
306 seq_printf(m, " redundant softirq offs: %11u\n", sr2);
307 #endif
310 static int lockdep_stats_show(struct seq_file *m, void *v)
312 struct lock_class *class;
313 unsigned long nr_unused = 0, nr_uncategorized = 0,
314 nr_irq_safe = 0, nr_irq_unsafe = 0,
315 nr_softirq_safe = 0, nr_softirq_unsafe = 0,
316 nr_hardirq_safe = 0, nr_hardirq_unsafe = 0,
317 nr_irq_read_safe = 0, nr_irq_read_unsafe = 0,
318 nr_softirq_read_safe = 0, nr_softirq_read_unsafe = 0,
319 nr_hardirq_read_safe = 0, nr_hardirq_read_unsafe = 0,
320 sum_forward_deps = 0, factor = 0;
322 list_for_each_entry(class, &all_lock_classes, lock_entry) {
324 if (class->usage_mask == 0)
325 nr_unused++;
326 if (class->usage_mask == LOCKF_USED)
327 nr_uncategorized++;
328 if (class->usage_mask & LOCKF_USED_IN_IRQ)
329 nr_irq_safe++;
330 if (class->usage_mask & LOCKF_ENABLED_IRQS)
331 nr_irq_unsafe++;
332 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
333 nr_softirq_safe++;
334 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
335 nr_softirq_unsafe++;
336 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
337 nr_hardirq_safe++;
338 if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
339 nr_hardirq_unsafe++;
340 if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
341 nr_irq_read_safe++;
342 if (class->usage_mask & LOCKF_ENABLED_IRQS_READ)
343 nr_irq_read_unsafe++;
344 if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
345 nr_softirq_read_safe++;
346 if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
347 nr_softirq_read_unsafe++;
348 if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
349 nr_hardirq_read_safe++;
350 if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
351 nr_hardirq_read_unsafe++;
353 sum_forward_deps += count_forward_deps(class);
355 #ifdef CONFIG_DEBUG_LOCKDEP
356 DEBUG_LOCKS_WARN_ON(debug_atomic_read(&nr_unused_locks) != nr_unused);
357 #endif
358 seq_printf(m, " lock-classes: %11lu [max: %lu]\n",
359 nr_lock_classes, MAX_LOCKDEP_KEYS);
360 seq_printf(m, " direct dependencies: %11lu [max: %lu]\n",
361 nr_list_entries, MAX_LOCKDEP_ENTRIES);
362 seq_printf(m, " indirect dependencies: %11lu\n",
363 sum_forward_deps);
366 * Total number of dependencies:
368 * All irq-safe locks may nest inside irq-unsafe locks,
369 * plus all the other known dependencies:
371 seq_printf(m, " all direct dependencies: %11lu\n",
372 nr_irq_unsafe * nr_irq_safe +
373 nr_hardirq_unsafe * nr_hardirq_safe +
374 nr_list_entries);
377 * Estimated factor between direct and indirect
378 * dependencies:
380 if (nr_list_entries)
381 factor = sum_forward_deps / nr_list_entries;
383 #ifdef CONFIG_PROVE_LOCKING
384 seq_printf(m, " dependency chains: %11lu [max: %lu]\n",
385 nr_lock_chains, MAX_LOCKDEP_CHAINS);
386 seq_printf(m, " dependency chain hlocks: %11d [max: %lu]\n",
387 nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);
388 #endif
390 #ifdef CONFIG_TRACE_IRQFLAGS
391 seq_printf(m, " in-hardirq chains: %11u\n",
392 nr_hardirq_chains);
393 seq_printf(m, " in-softirq chains: %11u\n",
394 nr_softirq_chains);
395 #endif
396 seq_printf(m, " in-process chains: %11u\n",
397 nr_process_chains);
398 seq_printf(m, " stack-trace entries: %11lu [max: %lu]\n",
399 nr_stack_trace_entries, MAX_STACK_TRACE_ENTRIES);
400 seq_printf(m, " combined max dependencies: %11u\n",
401 (nr_hardirq_chains + 1) *
402 (nr_softirq_chains + 1) *
403 (nr_process_chains + 1)
405 seq_printf(m, " hardirq-safe locks: %11lu\n",
406 nr_hardirq_safe);
407 seq_printf(m, " hardirq-unsafe locks: %11lu\n",
408 nr_hardirq_unsafe);
409 seq_printf(m, " softirq-safe locks: %11lu\n",
410 nr_softirq_safe);
411 seq_printf(m, " softirq-unsafe locks: %11lu\n",
412 nr_softirq_unsafe);
413 seq_printf(m, " irq-safe locks: %11lu\n",
414 nr_irq_safe);
415 seq_printf(m, " irq-unsafe locks: %11lu\n",
416 nr_irq_unsafe);
418 seq_printf(m, " hardirq-read-safe locks: %11lu\n",
419 nr_hardirq_read_safe);
420 seq_printf(m, " hardirq-read-unsafe locks: %11lu\n",
421 nr_hardirq_read_unsafe);
422 seq_printf(m, " softirq-read-safe locks: %11lu\n",
423 nr_softirq_read_safe);
424 seq_printf(m, " softirq-read-unsafe locks: %11lu\n",
425 nr_softirq_read_unsafe);
426 seq_printf(m, " irq-read-safe locks: %11lu\n",
427 nr_irq_read_safe);
428 seq_printf(m, " irq-read-unsafe locks: %11lu\n",
429 nr_irq_read_unsafe);
431 seq_printf(m, " uncategorized locks: %11lu\n",
432 nr_uncategorized);
433 seq_printf(m, " unused locks: %11lu\n",
434 nr_unused);
435 seq_printf(m, " max locking depth: %11u\n",
436 max_lockdep_depth);
437 seq_printf(m, " max recursion depth: %11u\n",
438 max_recursion_depth);
439 lockdep_stats_debug_show(m);
440 seq_printf(m, " debug_locks: %11u\n",
441 debug_locks);
443 return 0;
446 static int lockdep_stats_open(struct inode *inode, struct file *file)
448 return single_open(file, lockdep_stats_show, NULL);
451 static const struct file_operations proc_lockdep_stats_operations = {
452 .open = lockdep_stats_open,
453 .read = seq_read,
454 .llseek = seq_lseek,
455 .release = single_release,
458 #ifdef CONFIG_LOCK_STAT
460 struct lock_stat_data {
461 struct lock_class *class;
462 struct lock_class_stats stats;
465 struct lock_stat_seq {
466 struct lock_stat_data *iter;
467 struct lock_stat_data *iter_end;
468 struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
472 * sort on absolute number of contentions
474 static int lock_stat_cmp(const void *l, const void *r)
476 const struct lock_stat_data *dl = l, *dr = r;
477 unsigned long nl, nr;
479 nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;
480 nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr;
482 return nr - nl;
485 static void seq_line(struct seq_file *m, char c, int offset, int length)
487 int i;
489 for (i = 0; i < offset; i++)
490 seq_puts(m, " ");
491 for (i = 0; i < length; i++)
492 seq_printf(m, "%c", c);
493 seq_puts(m, "\n");
496 static void snprint_time(char *buf, size_t bufsiz, s64 nr)
498 unsigned long rem;
500 rem = do_div(nr, 1000); /* XXX: do_div_signed */
501 snprintf(buf, bufsiz, "%lld.%02d", (long long)nr, ((int)rem+5)/10);
504 static void seq_time(struct seq_file *m, s64 time)
506 char num[15];
508 snprint_time(num, sizeof(num), time);
509 seq_printf(m, " %14s", num);
512 static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
514 seq_printf(m, "%14lu", lt->nr);
515 seq_time(m, lt->min);
516 seq_time(m, lt->max);
517 seq_time(m, lt->total);
520 static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
522 char name[39];
523 struct lock_class *class;
524 struct lock_class_stats *stats;
525 int i, namelen;
527 class = data->class;
528 stats = &data->stats;
530 namelen = 38;
531 if (class->name_version > 1)
532 namelen -= 2; /* XXX truncates versions > 9 */
533 if (class->subclass)
534 namelen -= 2;
536 if (!class->name) {
537 char str[KSYM_NAME_LEN];
538 const char *key_name;
540 key_name = __get_key_name(class->key, str);
541 snprintf(name, namelen, "%s", key_name);
542 } else {
543 snprintf(name, namelen, "%s", class->name);
545 namelen = strlen(name);
546 if (class->name_version > 1) {
547 snprintf(name+namelen, 3, "#%d", class->name_version);
548 namelen += 2;
550 if (class->subclass) {
551 snprintf(name+namelen, 3, "/%d", class->subclass);
552 namelen += 2;
555 if (stats->write_holdtime.nr) {
556 if (stats->read_holdtime.nr)
557 seq_printf(m, "%38s-W:", name);
558 else
559 seq_printf(m, "%40s:", name);
561 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);
562 seq_lock_time(m, &stats->write_waittime);
563 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);
564 seq_lock_time(m, &stats->write_holdtime);
565 seq_puts(m, "\n");
568 if (stats->read_holdtime.nr) {
569 seq_printf(m, "%38s-R:", name);
570 seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);
571 seq_lock_time(m, &stats->read_waittime);
572 seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);
573 seq_lock_time(m, &stats->read_holdtime);
574 seq_puts(m, "\n");
577 if (stats->read_waittime.nr + stats->write_waittime.nr == 0)
578 return;
580 if (stats->read_holdtime.nr)
581 namelen += 2;
583 for (i = 0; i < ARRAY_SIZE(class->contention_point); i++) {
584 char sym[KSYM_SYMBOL_LEN];
585 char ip[32];
587 if (class->contention_point[i] == 0)
588 break;
590 if (!i)
591 seq_line(m, '-', 40-namelen, namelen);
593 sprint_symbol(sym, class->contention_point[i]);
594 snprintf(ip, sizeof(ip), "[<%p>]",
595 (void *)class->contention_point[i]);
596 seq_printf(m, "%40s %14lu %29s %s\n", name,
597 stats->contention_point[i],
598 ip, sym);
600 if (i) {
601 seq_puts(m, "\n");
602 seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
603 seq_puts(m, "\n");
607 static void seq_header(struct seq_file *m)
609 seq_printf(m, "lock_stat version 0.2\n");
610 seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
611 seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
612 "%14s %14s\n",
613 "class name",
614 "con-bounces",
615 "contentions",
616 "waittime-min",
617 "waittime-max",
618 "waittime-total",
619 "acq-bounces",
620 "acquisitions",
621 "holdtime-min",
622 "holdtime-max",
623 "holdtime-total");
624 seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
625 seq_printf(m, "\n");
628 static void *ls_start(struct seq_file *m, loff_t *pos)
630 struct lock_stat_seq *data = m->private;
632 if (*pos == 0)
633 return SEQ_START_TOKEN;
635 data->iter = data->stats + *pos;
636 if (data->iter >= data->iter_end)
637 data->iter = NULL;
639 return data->iter;
642 static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
644 struct lock_stat_seq *data = m->private;
646 (*pos)++;
648 if (v == SEQ_START_TOKEN)
649 data->iter = data->stats;
650 else {
651 data->iter = v;
652 data->iter++;
655 if (data->iter == data->iter_end)
656 data->iter = NULL;
658 return data->iter;
661 static void ls_stop(struct seq_file *m, void *v)
665 static int ls_show(struct seq_file *m, void *v)
667 if (v == SEQ_START_TOKEN)
668 seq_header(m);
669 else
670 seq_stats(m, v);
672 return 0;
675 static struct seq_operations lockstat_ops = {
676 .start = ls_start,
677 .next = ls_next,
678 .stop = ls_stop,
679 .show = ls_show,
682 static int lock_stat_open(struct inode *inode, struct file *file)
684 int res;
685 struct lock_class *class;
686 struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));
688 if (!data)
689 return -ENOMEM;
691 res = seq_open(file, &lockstat_ops);
692 if (!res) {
693 struct lock_stat_data *iter = data->stats;
694 struct seq_file *m = file->private_data;
696 data->iter = iter;
697 list_for_each_entry(class, &all_lock_classes, lock_entry) {
698 iter->class = class;
699 iter->stats = lock_stats(class);
700 iter++;
702 data->iter_end = iter;
704 sort(data->stats, data->iter_end - data->iter,
705 sizeof(struct lock_stat_data),
706 lock_stat_cmp, NULL);
708 m->private = data;
709 } else
710 vfree(data);
712 return res;
715 static ssize_t lock_stat_write(struct file *file, const char __user *buf,
716 size_t count, loff_t *ppos)
718 struct lock_class *class;
719 char c;
721 if (count) {
722 if (get_user(c, buf))
723 return -EFAULT;
725 if (c != '0')
726 return count;
728 list_for_each_entry(class, &all_lock_classes, lock_entry)
729 clear_lock_stats(class);
731 return count;
734 static int lock_stat_release(struct inode *inode, struct file *file)
736 struct seq_file *seq = file->private_data;
738 vfree(seq->private);
739 seq->private = NULL;
740 return seq_release(inode, file);
743 static const struct file_operations proc_lock_stat_operations = {
744 .open = lock_stat_open,
745 .write = lock_stat_write,
746 .read = seq_read,
747 .llseek = seq_lseek,
748 .release = lock_stat_release,
750 #endif /* CONFIG_LOCK_STAT */
752 static int __init lockdep_proc_init(void)
754 proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
755 #ifdef CONFIG_PROVE_LOCKING
756 proc_create("lockdep_chains", S_IRUSR, NULL,
757 &proc_lockdep_chains_operations);
758 #endif
759 proc_create("lockdep_stats", S_IRUSR, NULL,
760 &proc_lockdep_stats_operations);
762 #ifdef CONFIG_LOCK_STAT
763 proc_create("lock_stat", S_IRUSR, NULL, &proc_lock_stat_operations);
764 #endif
766 return 0;
769 __initcall(lockdep_proc_init);