Merge branch 'master' of git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux-2.6

1 files changed, 18 insertions, 9 deletions

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index f5dcd36d3151..429540c70d3f 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -140,7 +140,8 @@ static inline struct lock_class *hlock_class(struct held_lock *hlock)
 }
 
 #ifdef CONFIG_LOCK_STAT
-static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS], lock_stats);
+static DEFINE_PER_CPU(struct lock_class_stats[MAX_LOCKDEP_KEYS],
+                      cpu_lock_stats);
 
 static inline u64 lockstat_clock(void)
 {
@@ -168,7 +169,7 @@ static void lock_time_inc(struct lock_time *lt, u64 time)
         if (time > lt->max)
                 lt->max = time;
 
-        if (time < lt->min || !lt->min)
+        if (time < lt->min || !lt->nr)
                 lt->min = time;
 
         lt->total += time;
@@ -177,8 +178,15 @@ static void lock_time_inc(struct lock_time *lt, u64 time)
 
 static inline void lock_time_add(struct lock_time *src, struct lock_time *dst)
 {
-        dst->min += src->min;
-        dst->max += src->max;
+        if (!src->nr)
+                return;
+
+        if (src->max > dst->max)
+                dst->max = src->max;
+
+        if (src->min < dst->min || !dst->nr)
+                dst->min = src->min;
+
         dst->total += src->total;
         dst->nr += src->nr;
 }
@@ -191,7 +199,7 @@ struct lock_class_stats lock_stats(struct lock_class *class)
         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];
+                        &per_cpu(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];
@@ -218,7 +226,7 @@ void clear_lock_stats(struct lock_class *class)
 
         for_each_possible_cpu(cpu) {
                 struct lock_class_stats *cpu_stats =
-                        &per_cpu(lock_stats, cpu)[class - lock_classes];
+                        &per_cpu(cpu_lock_stats, cpu)[class - lock_classes];
 
                 memset(cpu_stats, 0, sizeof(struct lock_class_stats));
         }
@@ -228,12 +236,12 @@ void clear_lock_stats(struct lock_class *class)
 
 static struct lock_class_stats *get_lock_stats(struct lock_class *class)
 {
-        return &get_cpu_var(lock_stats)[class - lock_classes];
+        return &get_cpu_var(cpu_lock_stats)[class - lock_classes];
 }
 
 static void put_lock_stats(struct lock_class_stats *stats)
 {
-        put_cpu_var(lock_stats);
+        put_cpu_var(cpu_lock_stats);
 }
 
 static void lock_release_holdtime(struct held_lock *hlock)
@@ -379,7 +387,8 @@ static int save_trace(struct stack_trace *trace)
          * complete trace that maxes out the entries provided will be reported
          * as incomplete, friggin useless </rant>
          */
-        if (trace->entries[trace->nr_entries-1] == ULONG_MAX)
+        if (trace->nr_entries != 0 &&
+            trace->entries[trace->nr_entries-1] == ULONG_MAX)
                 trace->nr_entries--;
 
         trace->max_entries = trace->nr_entries;