[PATCH 8/8] kernel:lockdep:add statistics info for max bfs queue depth

[tom . leiming]

From: Ming Lei <tom.leiming@xxxxxxxxx>


Signed-off-by: Ming Lei <tom.leiming@xxxxxxxxx>
---
 kernel/lockdep.c           |    6 +++++-
 kernel/lockdep_internals.h |    3 ++-
 kernel/lockdep_proc.c      |    2 ++
 3 files changed, 9 insertions(+), 2 deletions(-)

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index faa39cb..b20f08b 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -929,7 +929,7 @@ static int add_lock_to_list(struct lock_class *class, struct lock_class *this,
 
 unsigned long bfs_accessed[BITS_TO_LONGS(MAX_LOCKDEP_ENTRIES)];
 static struct circular_queue  lock_cq;
-
+unsigned int max_bfs_queue_depth;
 static int __bfs(struct lock_list *source_entry,
 			void *data,
 			int (*match)(struct lock_list *entry, void *data),
@@ -975,6 +975,7 @@ static int __bfs(struct lock_list *source_entry,
 
 		list_for_each_entry(entry, head, entry) {
 			if (!lock_accessed(entry)) {
+				unsigned int cq_depth;
 				mark_lock_accessed(entry, lock);
 				if (match(entry, data)) {
 					*target_entry = entry;
@@ -986,6 +987,9 @@ static int __bfs(struct lock_list *source_entry,
 					ret = -1;
 					goto exit;
 				}
+				cq_depth = __cq_get_elem_count(cq);
+				if (max_bfs_queue_depth < cq_depth)
+					max_bfs_queue_depth = cq_depth;
 			}
 		}
 	}
diff --git a/kernel/lockdep_internals.h b/kernel/lockdep_internals.h
index b115aaa..6baa880 100644
--- a/kernel/lockdep_internals.h
+++ b/kernel/lockdep_internals.h
@@ -138,6 +138,7 @@ extern atomic_t nr_find_usage_backwards_recursions;
 #endif
 
 
+extern unsigned int max_bfs_queue_depth;
 extern unsigned long nr_list_entries;
 extern struct lock_list list_entries[MAX_LOCKDEP_ENTRIES];
 extern unsigned long bfs_accessed[];
@@ -191,7 +192,7 @@ static inline int __cq_dequeue(struct circular_queue *cq, unsigned long *elem)
 	return 0;
 }
 
-static inline int __cq_get_elem_count(struct circular_queue *cq)
+static inline unsigned int  __cq_get_elem_count(struct circular_queue *cq)
 {
 	return (cq->rear - cq->front)&(MAX_CIRCULAR_QUE_SIZE-1);
 }
diff --git a/kernel/lockdep_proc.c b/kernel/lockdep_proc.c
index d7135aa..9a1bf34 100644
--- a/kernel/lockdep_proc.c
+++ b/kernel/lockdep_proc.c
@@ -411,6 +411,8 @@ static int lockdep_stats_show(struct seq_file *m, void *v)
 			max_lockdep_depth);
 	seq_printf(m, " max recursion depth:           %11u\n",
 			max_recursion_depth);
+	seq_printf(m, " max bfs queue depth:           %11u\n",
+			max_bfs_queue_depth);
 	lockdep_stats_debug_show(m);
 	seq_printf(m, " debug_locks:                   %11u\n",
 			debug_locks);
-- 
1.6.0.GIT

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