sched: Get rid of lock_depth

Neil Brown pointed out that lock_depth somehow escaped the BKL
removal work.  Let's get rid of it now.

Note that the perf scripting utilities still have a bunch of
code for dealing with common_lock_depth in tracepoints; I have
left that in place in case anybody wants to use that code with
older kernels.

Suggested-by: Neil Brown <neilb@suse.de>
Signed-off-by: Jonathan Corbet <corbet@lwn.net>
Cc: Arnd Bergmann <arnd@arndb.de>
Cc: Peter Zijlstra <a.p.zijlstra@chello.nl>
Cc: Thomas Gleixner <tglx@linutronix.de>
Cc: Linus Torvalds <torvalds@linux-foundation.org>
Cc: Andrew Morton <akpm@linux-foundation.org>
Link: http://lkml.kernel.org/r/20110422111910.456c0e84@bike.lwn.net
Signed-off-by: Ingo Molnar <mingo@elte.hu>

1 files changed, 0 insertions, 7 deletions

diff --git a/kernel/mutex.c b/kernel/mutex.c
index fe4706cb0c5b..2c938e2337cd 100644
--- a/kernel/mutex.c
+++ b/kernel/mutex.c
@@ -163,13 +163,6 @@ __mutex_lock_common(struct mutex *lock, long state, unsigned int subclass,
                 struct task_struct *owner;
 
                 /*
-                 * If we own the BKL, then don't spin. The owner of
-                 * the mutex might be waiting on us to release the BKL.
-                 */
-                if (unlikely(current->lock_depth >= 0))
-                        break;
-
-                /*
                  * If there's an owner, wait for it to either
                  * release the lock or go to sleep.
                  */