X-Git-Url: https://git.openpandora.org/cgi-bin/gitweb.cgi?p=pandora-kernel.git;a=blobdiff_plain;f=include%2Flinux%2Flockdep.h;h=2186a64ee4b568f09649347b5bf04e5ed7a66cdb;hp=06aed8305bf3bc38061dc42c168c3b9d83f29492;hb=888a6f77e0418b049f83d37547c209b904d30af4;hpb=1067b6c2bea7fd2cc9da290d865ab3f3b91c8130

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 06aed8305bf3..2186a64ee4b5 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -31,6 +31,17 @@ extern int lock_stat;
 
 #define MAX_LOCKDEP_SUBCLASSES		8UL
 
+/*
+ * NR_LOCKDEP_CACHING_CLASSES ... Number of classes
+ * cached in the instance of lockdep_map
+ *
+ * Currently main class (subclass == 0) and signle depth subclass
+ * are cached in lockdep_map. This optimization is mainly targeting
+ * on rq->lock. double_rq_lock() acquires this highly competitive with
+ * single depth.
+ */
+#define NR_LOCKDEP_CACHING_CLASSES	2
+
 /*
  * Lock-classes are keyed via unique addresses, by embedding the
  * lockclass-key into the kernel (or module) .data section. (For
@@ -138,7 +149,7 @@ void clear_lock_stats(struct lock_class *class);
  */
 struct lockdep_map {
 	struct lock_class_key		*key;
-	struct lock_class		*class_cache;
+	struct lock_class		*class_cache[NR_LOCKDEP_CACHING_CLASSES];
 	const char			*name;
 #ifdef CONFIG_LOCK_STAT
 	int				cpu;