[PATCH] lockdep: core, reduce per-lock class-cache size
lockdep_map is embedded into every lock, which blows up data structure
sizes all around the kernel. Reduce the class-cache to be for the default
class only - that is used in 99.9% of the cases and even if we dont have a
class cached, the lookup in the class-hash is lockless.
This change reduces the per-lock dep_map overhead by 56 bytes on 64-bit
platforms and by 28 bytes on 32-bit platforms.
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Cc: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 316e0fb..c040a8c 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -120,7 +120,7 @@
*/
struct lockdep_map {
struct lock_class_key *key;
- struct lock_class *class[MAX_LOCKDEP_SUBCLASSES];
+ struct lock_class *class_cache;
const char *name;
};