diff options
Diffstat (limited to 'include/linux/lockdep.h')
| -rw-r--r-- | include/linux/lockdep.h | 13 |
1 files changed, 12 insertions, 1 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 17d050ce7ab..71c09b26c75 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -32,6 +32,17 @@ 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 * static locks we use the lock address itself as the key.) @@ -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; |