[PATCH] lockdep: locking init debugging improvement

Locking init improvement:

 - introduce and use __SPIN_LOCK_UNLOCKED for array initializations,
   to pass in the name string of locks, used by debugging

Signed-off-by: Ingo Molnar <mingo@elte.hu>
Signed-off-by: Arjan van de Ven <arjan@linux.intel.com>
Signed-off-by: Andrew Morton <akpm@osdl.org>
Signed-off-by: Linus Torvalds <torvalds@osdl.org>

1 files changed, 10 insertions, 2 deletions

diff --git a/include/linux/seqlock.h b/include/linux/seqlock.h
index 7bc5c7c12b54..46000936f8f1 100644
--- a/include/linux/seqlock.h
+++ b/include/linux/seqlock.h
@@ -38,9 +38,17 @@ typedef struct {
  * These macros triggered gcc-3.x compile-time problems.  We think these are
  * OK now.  Be cautious.
  */
-#define SEQLOCK_UNLOCKED { 0, SPIN_LOCK_UNLOCKED }
-#define seqlock_init(x) do { *(x) = (seqlock_t) SEQLOCK_UNLOCKED; } while (0)
+#define __SEQLOCK_UNLOCKED(lockname) \
+                 { 0, __SPIN_LOCK_UNLOCKED(lockname) }
 
+#define SEQLOCK_UNLOCKED \
+                 __SEQLOCK_UNLOCKED(old_style_seqlock_init)
+
+#define seqlock_init(x) \
+                do { *(x) = (seqlock_t) __SEQLOCK_UNLOCKED(x); } while (0)
+
+#define DEFINE_SEQLOCK(x) \
+                seqlock_t x = __SEQLOCK_UNLOCKED(x)
 
 /* Lock out other writers and update the count.
  * Acts like a normal spin_lock/unlock.