* Zan Lynx <[EMAIL PROTECTED]> wrote:

> Included Ingo in CC because I think he did the locking test.
> 
> The following is copied from a different boot, but looks the same to my
> eye as what I got on the console:
> 
> ------------------------
> | Locking API testsuite:
> ----------------------------------------------------------------------------
>                                  | spin |wlock |rlock |mutex | wsem | rsem |
>   --------------------------------------------------------------------------
>                      A-A deadlock:  ok  |
> 
> It just sticks there.  I assume that means a problem with wlock?

does the patch below from Nick fix it? It went upstream just after 
rc8-mm1 so rc8-mm1 might be missing it.

        Ingo

------------------>
commit 5a26db5bd25cf4bf32ae9fa9f6136b6b6d5b45c5
Author: Nick Piggin <[EMAIL PROTECTED]>
Date:   Wed Jan 16 09:51:58 2008 +0100

    lockdep: fix internal double unlock during self-test
    Lockdep, during self-test (when it was simulating double unlocks) was
    sometimes unconditionally unlocking a spinlock when it had not been
    locked. This won't work for ticket locks.
    
    Signed-off-by: Nick Piggin <[EMAIL PROTECTED]>
    Signed-off-by: Ingo Molnar <[EMAIL PROTECTED]>
    Signed-off-by: Peter Zijlstra <[EMAIL PROTECTED]>

diff --git a/kernel/lockdep.c b/kernel/lockdep.c
index 723bd9f..4335f12 100644
--- a/kernel/lockdep.c
+++ b/kernel/lockdep.c
@@ -2943,9 +2943,10 @@ void lockdep_free_key_range(void *start, unsigned long 
size)
        struct list_head *head;
        unsigned long flags;
        int i;
+       int locked;
 
        raw_local_irq_save(flags);
-       graph_lock();
+       locked = graph_lock();
 
        /*
         * Unhash all classes that were created by this module:
@@ -2959,7 +2960,8 @@ void lockdep_free_key_range(void *start, unsigned long 
size)
                                zap_class(class);
        }
 
-       graph_unlock();
+       if (locked)
+               graph_unlock();
        raw_local_irq_restore(flags);
 }
 
@@ -2969,6 +2971,7 @@ void lockdep_reset_lock(struct lockdep_map *lock)
        struct list_head *head;
        unsigned long flags;
        int i, j;
+       int locked;
 
        raw_local_irq_save(flags);
 
@@ -2987,7 +2990,7 @@ void lockdep_reset_lock(struct lockdep_map *lock)
         * Debug check: in the end all mapped classes should
         * be gone.
         */
-       graph_lock();
+       locked = graph_lock();
        for (i = 0; i < CLASSHASH_SIZE; i++) {
                head = classhash_table + i;
                if (list_empty(head))
@@ -3000,7 +3003,8 @@ void lockdep_reset_lock(struct lockdep_map *lock)
                        }
                }
        }
-       graph_unlock();
+       if (locked)
+               graph_unlock();
 
 out_restore:
        raw_local_irq_restore(flags);
--
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