1 files changed, 44 insertions, 0 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 70ca4db28aff..a8dc99d9fef7 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];