Merge commit 'v2.6.31-rc8' into core/locking
[linux-2.6.git] / kernel / lockdep_proc.c
index f6e72ea..d4b3dbc 100644 (file)
  *
  * Started by Ingo Molnar:
  *
- *  Copyright (C) 2006 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2006,2007 Red Hat, Inc., Ingo Molnar <mingo@redhat.com>
+ *  Copyright (C) 2007 Red Hat, Inc., Peter Zijlstra <pzijlstr@redhat.com>
  *
  * Code for /proc/lockdep and /proc/lockdep_stats:
  *
  */
-#include <linux/sched.h>
 #include <linux/module.h>
 #include <linux/proc_fs.h>
 #include <linux/seq_file.h>
 #include <linux/kallsyms.h>
 #include <linux/debug_locks.h>
+#include <linux/vmalloc.h>
+#include <linux/sort.h>
+#include <asm/uaccess.h>
+#include <asm/div64.h>
 
 #include "lockdep_internals.h"
 
 static void *l_next(struct seq_file *m, void *v, loff_t *pos)
 {
-       struct lock_class *class = v;
-
-       (*pos)++;
-
-       if (class->lock_entry.next != &all_lock_classes)
-               class = list_entry(class->lock_entry.next, struct lock_class,
-                                 lock_entry);
-       else
-               class = NULL;
-       m->private = class;
-
-       return class;
+       return seq_list_next(v, &all_lock_classes, pos);
 }
 
 static void *l_start(struct seq_file *m, loff_t *pos)
 {
-       struct lock_class *class = m->private;
-
-       if (&class->lock_entry == all_lock_classes.next)
-               seq_printf(m, "all lock classes:\n");
-
-       return class;
+       return seq_list_start_head(&all_lock_classes, *pos);
 }
 
 static void l_stop(struct seq_file *m, void *v)
 {
 }
 
-static unsigned long count_forward_deps(struct lock_class *class)
+static void print_name(struct seq_file *m, struct lock_class *class)
 {
-       struct lock_list *entry;
-       unsigned long ret = 1;
-
-       /*
-        * Recurse this class's dependency list:
-        */
-       list_for_each_entry(entry, &class->locks_after, entry)
-               ret += count_forward_deps(entry->class);
+       char str[128];
+       const char *name = class->name;
 
-       return ret;
+       if (!name) {
+               name = __get_key_name(class->key, str);
+               seq_printf(m, "%s", name);
+       } else{
+               seq_printf(m, "%s", name);
+               if (class->name_version > 1)
+                       seq_printf(m, "#%d", class->name_version);
+               if (class->subclass)
+                       seq_printf(m, "/%d", class->subclass);
+       }
 }
 
-static unsigned long count_backward_deps(struct lock_class *class)
+static int l_show(struct seq_file *m, void *v)
 {
+       struct lock_class *class = list_entry(v, struct lock_class, lock_entry);
        struct lock_list *entry;
-       unsigned long ret = 1;
-
-       /*
-        * Recurse this class's dependency list:
-        */
-       list_for_each_entry(entry, &class->locks_before, entry)
-               ret += count_backward_deps(entry->class);
+       char usage[LOCK_USAGE_CHARS];
 
-       return ret;
-}
-
-static int l_show(struct seq_file *m, void *v)
-{
-       unsigned long nr_forward_deps, nr_backward_deps;
-       struct lock_class *class = m->private;
-       char str[128], c1, c2, c3, c4;
-       const char *name;
+       if (v == &all_lock_classes) {
+               seq_printf(m, "all lock classes:\n");
+               return 0;
+       }
 
        seq_printf(m, "%p", class->key);
 #ifdef CONFIG_DEBUG_LOCKDEP
        seq_printf(m, " OPS:%8ld", class->ops);
 #endif
-       nr_forward_deps = count_forward_deps(class);
-       seq_printf(m, " FD:%5ld", nr_forward_deps);
+#ifdef CONFIG_PROVE_LOCKING
+       seq_printf(m, " FD:%5ld", lockdep_count_forward_deps(class));
+       seq_printf(m, " BD:%5ld", lockdep_count_backward_deps(class));
+#endif
 
-       nr_backward_deps = count_backward_deps(class);
-       seq_printf(m, " BD:%5ld", nr_backward_deps);
+       get_usage_chars(class, usage);
+       seq_printf(m, " %s", usage);
 
-       get_usage_chars(class, &c1, &c2, &c3, &c4);
-       seq_printf(m, " %c%c%c%c", c1, c2, c3, c4);
+       seq_printf(m, ": ");
+       print_name(m, class);
+       seq_puts(m, "\n");
 
-       name = class->name;
-       if (!name) {
-               name = __get_key_name(class->key, str);
-               seq_printf(m, ": %s", name);
-       } else{
-               seq_printf(m, ": %s", name);
-               if (class->name_version > 1)
-                       seq_printf(m, "#%d", class->name_version);
-               if (class->subclass)
-                       seq_printf(m, "/%d", class->subclass);
+       list_for_each_entry(entry, &class->locks_after, entry) {
+               if (entry->distance == 1) {
+                       seq_printf(m, " -> [%p] ", entry->class->key);
+                       print_name(m, entry->class);
+                       seq_puts(m, "\n");
+               }
        }
        seq_puts(m, "\n");
 
        return 0;
 }
 
-static struct seq_operations lockdep_ops = {
+static const struct seq_operations lockdep_ops = {
        .start  = l_start,
        .next   = l_next,
        .stop   = l_stop,
@@ -122,25 +102,84 @@ static struct seq_operations lockdep_ops = {
 
 static int lockdep_open(struct inode *inode, struct file *file)
 {
-       int res = seq_open(file, &lockdep_ops);
-       if (!res) {
-               struct seq_file *m = file->private_data;
+       return seq_open(file, &lockdep_ops);
+}
 
-               if (!list_empty(&all_lock_classes))
-                       m->private = list_entry(all_lock_classes.next,
-                                       struct lock_class, lock_entry);
-               else
-                       m->private = NULL;
+static const struct file_operations proc_lockdep_operations = {
+       .open           = lockdep_open,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = seq_release,
+};
+
+#ifdef CONFIG_PROVE_LOCKING
+static void *lc_start(struct seq_file *m, loff_t *pos)
+{
+       if (*pos == 0)
+               return SEQ_START_TOKEN;
+
+       if (*pos - 1 < nr_lock_chains)
+               return lock_chains + (*pos - 1);
+
+       return NULL;
+}
+
+static void *lc_next(struct seq_file *m, void *v, loff_t *pos)
+{
+       (*pos)++;
+       return lc_start(m, pos);
+}
+
+static void lc_stop(struct seq_file *m, void *v)
+{
+}
+
+static int lc_show(struct seq_file *m, void *v)
+{
+       struct lock_chain *chain = v;
+       struct lock_class *class;
+       int i;
+
+       if (v == SEQ_START_TOKEN) {
+               seq_printf(m, "all lock chains:\n");
+               return 0;
        }
-       return res;
+
+       seq_printf(m, "irq_context: %d\n", chain->irq_context);
+
+       for (i = 0; i < chain->depth; i++) {
+               class = lock_chain_get_class(chain, i);
+               if (!class->key)
+                       continue;
+
+               seq_printf(m, "[%p] ", class->key);
+               print_name(m, class);
+               seq_puts(m, "\n");
+       }
+       seq_puts(m, "\n");
+
+       return 0;
 }
 
-static struct file_operations proc_lockdep_operations = {
-       .open           = lockdep_open,
+static const struct seq_operations lockdep_chains_ops = {
+       .start  = lc_start,
+       .next   = lc_next,
+       .stop   = lc_stop,
+       .show   = lc_show,
+};
+
+static int lockdep_chains_open(struct inode *inode, struct file *file)
+{
+       return seq_open(file, &lockdep_chains_ops);
+}
+
+static const struct file_operations proc_lockdep_chains_operations = {
+       .open           = lockdep_chains_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
        .release        = seq_release,
 };
+#endif /* CONFIG_PROVE_LOCKING */
 
 static void lockdep_stats_debug_show(struct seq_file *m)
 {
@@ -160,16 +199,10 @@ static void lockdep_stats_debug_show(struct seq_file *m)
                debug_atomic_read(&chain_lookup_hits));
        seq_printf(m, " cyclic checks:                 %11u\n",
                debug_atomic_read(&nr_cyclic_checks));
-       seq_printf(m, " cyclic-check recursions:       %11u\n",
-               debug_atomic_read(&nr_cyclic_check_recursions));
        seq_printf(m, " find-mask forwards checks:     %11u\n",
                debug_atomic_read(&nr_find_usage_forwards_checks));
-       seq_printf(m, " find-mask forwards recursions: %11u\n",
-               debug_atomic_read(&nr_find_usage_forwards_recursions));
        seq_printf(m, " find-mask backwards checks:    %11u\n",
                debug_atomic_read(&nr_find_usage_backwards_checks));
-       seq_printf(m, " find-mask backwards recursions:%11u\n",
-               debug_atomic_read(&nr_find_usage_backwards_recursions));
 
        seq_printf(m, " hardirq on events:             %11u\n", hi1);
        seq_printf(m, " hardirq off events:            %11u\n", hi2);
@@ -202,32 +235,34 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
                        nr_uncategorized++;
                if (class->usage_mask & LOCKF_USED_IN_IRQ)
                        nr_irq_safe++;
-               if (class->usage_mask & LOCKF_ENABLED_IRQS)
+               if (class->usage_mask & LOCKF_ENABLED_IRQ)
                        nr_irq_unsafe++;
                if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ)
                        nr_softirq_safe++;
-               if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS)
+               if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ)
                        nr_softirq_unsafe++;
                if (class->usage_mask & LOCKF_USED_IN_HARDIRQ)
                        nr_hardirq_safe++;
-               if (class->usage_mask & LOCKF_ENABLED_HARDIRQS)
+               if (class->usage_mask & LOCKF_ENABLED_HARDIRQ)
                        nr_hardirq_unsafe++;
                if (class->usage_mask & LOCKF_USED_IN_IRQ_READ)
                        nr_irq_read_safe++;
-               if (class->usage_mask & LOCKF_ENABLED_IRQS_READ)
+               if (class->usage_mask & LOCKF_ENABLED_IRQ_READ)
                        nr_irq_read_unsafe++;
                if (class->usage_mask & LOCKF_USED_IN_SOFTIRQ_READ)
                        nr_softirq_read_safe++;
-               if (class->usage_mask & LOCKF_ENABLED_SOFTIRQS_READ)
+               if (class->usage_mask & LOCKF_ENABLED_SOFTIRQ_READ)
                        nr_softirq_read_unsafe++;
                if (class->usage_mask & LOCKF_USED_IN_HARDIRQ_READ)
                        nr_hardirq_read_safe++;
-               if (class->usage_mask & LOCKF_ENABLED_HARDIRQS_READ)
+               if (class->usage_mask & LOCKF_ENABLED_HARDIRQ_READ)
                        nr_hardirq_read_unsafe++;
 
-               sum_forward_deps += count_forward_deps(class);
+#ifdef CONFIG_PROVE_LOCKING
+               sum_forward_deps += lockdep_count_forward_deps(class);
+#endif
        }
-#ifdef CONFIG_LOCKDEP_DEBUG
+#ifdef CONFIG_DEBUG_LOCKDEP
        DEBUG_LOCKS_WARN_ON(debug_atomic_read(&nr_unused_locks) != nr_unused);
 #endif
        seq_printf(m, " lock-classes:                  %11lu [max: %lu]\n",
@@ -255,8 +290,12 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
        if (nr_list_entries)
                factor = sum_forward_deps / nr_list_entries;
 
+#ifdef CONFIG_PROVE_LOCKING
        seq_printf(m, " dependency chains:             %11lu [max: %lu]\n",
                        nr_lock_chains, MAX_LOCKDEP_CHAINS);
+       seq_printf(m, " dependency chain hlocks:       %11d [max: %lu]\n",
+                       nr_chain_hlocks, MAX_LOCKDEP_CHAIN_HLOCKS);
+#endif
 
 #ifdef CONFIG_TRACE_IRQFLAGS
        seq_printf(m, " in-hardirq chains:             %11u\n",
@@ -305,8 +344,10 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
                        nr_unused);
        seq_printf(m, " max locking depth:             %11u\n",
                        max_lockdep_depth);
-       seq_printf(m, " max recursion depth:           %11u\n",
-                       max_recursion_depth);
+#ifdef CONFIG_PROVE_LOCKING
+       seq_printf(m, " max bfs queue depth:           %11u\n",
+                       max_bfs_queue_depth);
+#endif
        lockdep_stats_debug_show(m);
        seq_printf(m, " debug_locks:                   %11u\n",
                        debug_locks);
@@ -319,24 +360,329 @@ static int lockdep_stats_open(struct inode *inode, struct file *file)
        return single_open(file, lockdep_stats_show, NULL);
 }
 
-static struct file_operations proc_lockdep_stats_operations = {
+static const struct file_operations proc_lockdep_stats_operations = {
        .open           = lockdep_stats_open,
        .read           = seq_read,
        .llseek         = seq_lseek,
-       .release        = seq_release,
+       .release        = single_release,
 };
 
-static int __init lockdep_proc_init(void)
+#ifdef CONFIG_LOCK_STAT
+
+struct lock_stat_data {
+       struct lock_class *class;
+       struct lock_class_stats stats;
+};
+
+struct lock_stat_seq {
+       struct lock_stat_data *iter_end;
+       struct lock_stat_data stats[MAX_LOCKDEP_KEYS];
+};
+
+/*
+ * sort on absolute number of contentions
+ */
+static int lock_stat_cmp(const void *l, const void *r)
+{
+       const struct lock_stat_data *dl = l, *dr = r;
+       unsigned long nl, nr;
+
+       nl = dl->stats.read_waittime.nr + dl->stats.write_waittime.nr;
+       nr = dr->stats.read_waittime.nr + dr->stats.write_waittime.nr;
+
+       return nr - nl;
+}
+
+static void seq_line(struct seq_file *m, char c, int offset, int length)
+{
+       int i;
+
+       for (i = 0; i < offset; i++)
+               seq_puts(m, " ");
+       for (i = 0; i < length; i++)
+               seq_printf(m, "%c", c);
+       seq_puts(m, "\n");
+}
+
+static void snprint_time(char *buf, size_t bufsiz, s64 nr)
+{
+       s64 div;
+       s32 rem;
+
+       nr += 5; /* for display rounding */
+       div = div_s64_rem(nr, 1000, &rem);
+       snprintf(buf, bufsiz, "%lld.%02d", (long long)div, (int)rem/10);
+}
+
+static void seq_time(struct seq_file *m, s64 time)
+{
+       char num[15];
+
+       snprint_time(num, sizeof(num), time);
+       seq_printf(m, " %14s", num);
+}
+
+static void seq_lock_time(struct seq_file *m, struct lock_time *lt)
+{
+       seq_printf(m, "%14lu", lt->nr);
+       seq_time(m, lt->min);
+       seq_time(m, lt->max);
+       seq_time(m, lt->total);
+}
+
+static void seq_stats(struct seq_file *m, struct lock_stat_data *data)
+{
+       char name[39];
+       struct lock_class *class;
+       struct lock_class_stats *stats;
+       int i, namelen;
+
+       class = data->class;
+       stats = &data->stats;
+
+       namelen = 38;
+       if (class->name_version > 1)
+               namelen -= 2; /* XXX truncates versions > 9 */
+       if (class->subclass)
+               namelen -= 2;
+
+       if (!class->name) {
+               char str[KSYM_NAME_LEN];
+               const char *key_name;
+
+               key_name = __get_key_name(class->key, str);
+               snprintf(name, namelen, "%s", key_name);
+       } else {
+               snprintf(name, namelen, "%s", class->name);
+       }
+       namelen = strlen(name);
+       if (class->name_version > 1) {
+               snprintf(name+namelen, 3, "#%d", class->name_version);
+               namelen += 2;
+       }
+       if (class->subclass) {
+               snprintf(name+namelen, 3, "/%d", class->subclass);
+               namelen += 2;
+       }
+
+       if (stats->write_holdtime.nr) {
+               if (stats->read_holdtime.nr)
+                       seq_printf(m, "%38s-W:", name);
+               else
+                       seq_printf(m, "%40s:", name);
+
+               seq_printf(m, "%14lu ", stats->bounces[bounce_contended_write]);
+               seq_lock_time(m, &stats->write_waittime);
+               seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_write]);
+               seq_lock_time(m, &stats->write_holdtime);
+               seq_puts(m, "\n");
+       }
+
+       if (stats->read_holdtime.nr) {
+               seq_printf(m, "%38s-R:", name);
+               seq_printf(m, "%14lu ", stats->bounces[bounce_contended_read]);
+               seq_lock_time(m, &stats->read_waittime);
+               seq_printf(m, " %14lu ", stats->bounces[bounce_acquired_read]);
+               seq_lock_time(m, &stats->read_holdtime);
+               seq_puts(m, "\n");
+       }
+
+       if (stats->read_waittime.nr + stats->write_waittime.nr == 0)
+               return;
+
+       if (stats->read_holdtime.nr)
+               namelen += 2;
+
+       for (i = 0; i < LOCKSTAT_POINTS; i++) {
+               char sym[KSYM_SYMBOL_LEN];
+               char ip[32];
+
+               if (class->contention_point[i] == 0)
+                       break;
+
+               if (!i)
+                       seq_line(m, '-', 40-namelen, namelen);
+
+               sprint_symbol(sym, class->contention_point[i]);
+               snprintf(ip, sizeof(ip), "[<%p>]",
+                               (void *)class->contention_point[i]);
+               seq_printf(m, "%40s %14lu %29s %s\n", name,
+                               stats->contention_point[i],
+                               ip, sym);
+       }
+       for (i = 0; i < LOCKSTAT_POINTS; i++) {
+               char sym[KSYM_SYMBOL_LEN];
+               char ip[32];
+
+               if (class->contending_point[i] == 0)
+                       break;
+
+               if (!i)
+                       seq_line(m, '-', 40-namelen, namelen);
+
+               sprint_symbol(sym, class->contending_point[i]);
+               snprintf(ip, sizeof(ip), "[<%p>]",
+                               (void *)class->contending_point[i]);
+               seq_printf(m, "%40s %14lu %29s %s\n", name,
+                               stats->contending_point[i],
+                               ip, sym);
+       }
+       if (i) {
+               seq_puts(m, "\n");
+               seq_line(m, '.', 0, 40 + 1 + 10 * (14 + 1));
+               seq_puts(m, "\n");
+       }
+}
+
+static void seq_header(struct seq_file *m)
+{
+       seq_printf(m, "lock_stat version 0.3\n");
+
+       if (unlikely(!debug_locks))
+               seq_printf(m, "*WARNING* lock debugging disabled!! - possibly due to a lockdep warning\n");
+
+       seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
+       seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s "
+                       "%14s %14s\n",
+                       "class name",
+                       "con-bounces",
+                       "contentions",
+                       "waittime-min",
+                       "waittime-max",
+                       "waittime-total",
+                       "acq-bounces",
+                       "acquisitions",
+                       "holdtime-min",
+                       "holdtime-max",
+                       "holdtime-total");
+       seq_line(m, '-', 0, 40 + 1 + 10 * (14 + 1));
+       seq_printf(m, "\n");
+}
+
+static void *ls_start(struct seq_file *m, loff_t *pos)
 {
-       struct proc_dir_entry *entry;
+       struct lock_stat_seq *data = m->private;
+       struct lock_stat_data *iter;
+
+       if (*pos == 0)
+               return SEQ_START_TOKEN;
+
+       iter = data->stats + (*pos - 1);
+       if (iter >= data->iter_end)
+               iter = NULL;
 
-       entry = create_proc_entry("lockdep", S_IRUSR, NULL);
-       if (entry)
-               entry->proc_fops = &proc_lockdep_operations;
+       return iter;
+}
 
-       entry = create_proc_entry("lockdep_stats", S_IRUSR, NULL);
-       if (entry)
-               entry->proc_fops = &proc_lockdep_stats_operations;
+static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
+{
+       (*pos)++;
+       return ls_start(m, pos);
+}
+
+static void ls_stop(struct seq_file *m, void *v)
+{
+}
+
+static int ls_show(struct seq_file *m, void *v)
+{
+       if (v == SEQ_START_TOKEN)
+               seq_header(m);
+       else
+               seq_stats(m, v);
+
+       return 0;
+}
+
+static struct seq_operations lockstat_ops = {
+       .start  = ls_start,
+       .next   = ls_next,
+       .stop   = ls_stop,
+       .show   = ls_show,
+};
+
+static int lock_stat_open(struct inode *inode, struct file *file)
+{
+       int res;
+       struct lock_class *class;
+       struct lock_stat_seq *data = vmalloc(sizeof(struct lock_stat_seq));
+
+       if (!data)
+               return -ENOMEM;
+
+       res = seq_open(file, &lockstat_ops);
+       if (!res) {
+               struct lock_stat_data *iter = data->stats;
+               struct seq_file *m = file->private_data;
+
+               list_for_each_entry(class, &all_lock_classes, lock_entry) {
+                       iter->class = class;
+                       iter->stats = lock_stats(class);
+                       iter++;
+               }
+               data->iter_end = iter;
+
+               sort(data->stats, data->iter_end - data->stats,
+                               sizeof(struct lock_stat_data),
+                               lock_stat_cmp, NULL);
+
+               m->private = data;
+       } else
+               vfree(data);
+
+       return res;
+}
+
+static ssize_t lock_stat_write(struct file *file, const char __user *buf,
+                              size_t count, loff_t *ppos)
+{
+       struct lock_class *class;
+       char c;
+
+       if (count) {
+               if (get_user(c, buf))
+                       return -EFAULT;
+
+               if (c != '0')
+                       return count;
+
+               list_for_each_entry(class, &all_lock_classes, lock_entry)
+                       clear_lock_stats(class);
+       }
+       return count;
+}
+
+static int lock_stat_release(struct inode *inode, struct file *file)
+{
+       struct seq_file *seq = file->private_data;
+
+       vfree(seq->private);
+       return seq_release(inode, file);
+}
+
+static const struct file_operations proc_lock_stat_operations = {
+       .open           = lock_stat_open,
+       .write          = lock_stat_write,
+       .read           = seq_read,
+       .llseek         = seq_lseek,
+       .release        = lock_stat_release,
+};
+#endif /* CONFIG_LOCK_STAT */
+
+static int __init lockdep_proc_init(void)
+{
+       proc_create("lockdep", S_IRUSR, NULL, &proc_lockdep_operations);
+#ifdef CONFIG_PROVE_LOCKING
+       proc_create("lockdep_chains", S_IRUSR, NULL,
+                   &proc_lockdep_chains_operations);
+#endif
+       proc_create("lockdep_stats", S_IRUSR, NULL,
+                   &proc_lockdep_stats_operations);
+
+#ifdef CONFIG_LOCK_STAT
+       proc_create("lock_stat", S_IRUSR | S_IWUSR, NULL,
+                   &proc_lock_stat_operations);
+#endif
 
        return 0;
 }