diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 70ca4db28affad40a94e55d7fe7f5e62dac27f1f..a8dc99d9fef7566a48884d7d9ae1b2a177c27906 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -149,6 +149,50 @@ static void lock_time_inc(struct lock_time *lt, s64 time)
lt->nr++;
}
+static inline void lock_time_add(struct lock_time *src, struct lock_time *dst)
+{
+ dst->min += src->min;
+ dst->max += src->max;
+ dst->total += src->total;
+ dst->nr += src->nr;
+}
+
+struct lock_class_stats lock_stats(struct lock_class *class)
+{
+ struct lock_class_stats stats;
+ int cpu, i;
+
+ memset(&stats, 0, sizeof(struct lock_class_stats));
+ for_each_possible_cpu(cpu) {
+ struct lock_class_stats *pcs =
+ &per_cpu(lock_stats, cpu)[class - lock_classes];
+
+ for (i = 0; i < ARRAY_SIZE(stats.contention_point); i++)
+ stats.contention_point[i] += pcs->contention_point[i];
+
+ lock_time_add(&pcs->read_waittime, &stats.read_waittime);
+ lock_time_add(&pcs->write_waittime, &stats.write_waittime);
+
+ lock_time_add(&pcs->read_holdtime, &stats.read_holdtime);
+ lock_time_add(&pcs->write_holdtime, &stats.write_holdtime);
+ }
+
+ return stats;
+}
+
+void clear_lock_stats(struct lock_class *class)
+{
+ int cpu;
+
+ for_each_possible_cpu(cpu) {
+ struct lock_class_stats *cpu_stats =
+ &per_cpu(lock_stats, cpu)[class - lock_classes];
+
+ memset(cpu_stats, 0, sizeof(struct lock_class_stats));
+ }
+ memset(class->contention_point, 0, sizeof(class->contention_point));
+}
+
static struct lock_class_stats *get_lock_stats(struct lock_class *class)
{
return &get_cpu_var(lock_stats)[class - lock_classes];
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index 2fde34127e2ee663a3ecf9a1d3b05101096153b6..e682926c9ad6dcc74d988e8c878d030c535f1ab9 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -15,6 +15,10 @@
#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"
@@ -344,6 +348,262 @@ static const struct file_operations proc_lockdep_stats_operations = {
.release = seq_release,
};
+#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;
+ 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)
+{
+ unsigned long rem;
+
+ rem = do_div(nr, 1000); /* XXX: do_div_signed */
+ snprintf(buf, bufsiz, "%lld.%02d", (long long)nr, ((int)rem+5)/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;
+
+ snprintf(name, 38, "%s", class->name);
+ namelen = strlen(name);
+
+ if (stats->write_holdtime.nr) {
+ if (stats->read_holdtime.nr)
+ seq_printf(m, "%38s-W:", name);
+ else
+ seq_printf(m, "%40s:", name);
+
+ seq_lock_time(m, &stats->write_waittime);
+ seq_puts(m, " ");
+ seq_lock_time(m, &stats->write_holdtime);
+ seq_puts(m, "\n");
+ }
+
+ if (stats->read_holdtime.nr) {
+ seq_printf(m, "%38s-R:", name);
+ seq_lock_time(m, &stats->read_waittime);
+ seq_puts(m, " ");
+ 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 < ARRAY_SIZE(class->contention_point); 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);
+ }
+ if (i) {
+ seq_puts(m, "\n");
+ seq_line(m, '.', 0, 40 + 1 + 8 * (14 + 1));
+ seq_puts(m, "\n");
+ }
+}
+
+static void seq_header(struct seq_file *m)
+{
+ seq_printf(m, "lock_stat version 0.1\n");
+ seq_line(m, '-', 0, 40 + 1 + 8 * (14 + 1));
+ seq_printf(m, "%40s %14s %14s %14s %14s %14s %14s %14s %14s\n",
+ "class name",
+ "contentions",
+ "waittime-min",
+ "waittime-max",
+ "waittime-total",
+ "acquisitions",
+ "holdtime-min",
+ "holdtime-max",
+ "holdtime-total");
+ seq_line(m, '-', 0, 40 + 1 + 8 * (14 + 1));
+ seq_printf(m, "\n");
+}
+
+static void *ls_start(struct seq_file *m, loff_t *pos)
+{
+ struct lock_stat_seq *data = m->private;
+
+ if (data->iter == data->stats)
+ seq_header(m);
+
+ return data->iter;
+}
+
+static void *ls_next(struct seq_file *m, void *v, loff_t *pos)
+{
+ struct lock_stat_seq *data = m->private;
+
+ (*pos)++;
+
+ data->iter = v;
+ data->iter++;
+ if (data->iter == data->iter_end)
+ data->iter = NULL;
+
+ return data->iter;
+}
+
+static void ls_stop(struct seq_file *m, void *v)
+{
+}
+
+static int ls_show(struct seq_file *m, void *v)
+{
+ struct lock_stat_seq *data = m->private;
+
+ seq_stats(m, data->iter);
+ 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;
+
+ data->iter = iter;
+ 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->iter,
+ 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);
+ seq->private = NULL;
+ 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)
{
struct proc_dir_entry *entry;
@@ -356,6 +616,12 @@ static int __init lockdep_proc_init(void)
if (entry)
entry->proc_fops = &proc_lockdep_stats_operations;
+#ifdef CONFIG_LOCK_STAT
+ entry = create_proc_entry("lock_stat", S_IRUSR, NULL);
+ if (entry)
+ entry->proc_fops = &proc_lock_stat_operations;
+#endif
+
return 0;
}