[tip:core/locking 2/3] lockdep:define preallocated "stack" for BFS as per cpu variable

[tom.leiming@gmail.com]

From: Ming Lei <tom.leiming@gmail.com>

Signed-off-by: Ming Lei <tom.leiming@gmail.com>
---
 kernel/lockdep.c |    5 +++--
 1 files changed, 3 insertions(+), 2 deletions(-)

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 1b1796a..1583439 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -847,7 +847,7 @@ struct circular_queue {
 	unsigned int  front, rear;
 };
 
-static struct circular_queue lock_cq;
+static DEFINE_PER_CPU(struct circular_queue, lock_cq);
 
 unsigned int max_bfs_queue_depth;
 
@@ -937,7 +937,7 @@ static int __bfs(struct lock_list *source_entry,
 {
 	struct lock_list *entry;
 	struct list_head *head;
-	struct circular_queue *cq = &lock_cq;
+	struct circular_queue *cq = &get_cpu_var(lock_cq);
 	int ret = 1;
 
 	if (match(source_entry, data)) {
@@ -993,6 +993,7 @@ static int __bfs(struct lock_list *source_entry,
 		}
 	}
 exit:
+	put_cpu_var(lock_cq);
 	return ret;
 }
 
-- 
1.6.0.GIT