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| author | Peter Zijlstra <a.p.zijlstra@chello.nl> | 2008-08-11 09:30:24 +0200 |
|---|---|---|
| committer | Ingo Molnar <mingo@elte.hu> | 2008-08-11 09:30:24 +0200 |
| commit | b7d39aff91454f2534db2275f55908656ec0470c (patch) | |
| tree | 24481f2fe7206ef69800a33df6ac3e1716085326 /kernel | |
| parent | 7531e2f34d1d551b096143f19111139f0dd84c8b (diff) | |
| download | linux-b7d39aff91454f2534db2275f55908656ec0470c.tar.gz linux-b7d39aff91454f2534db2275f55908656ec0470c.tar.bz2 linux-b7d39aff91454f2534db2275f55908656ec0470c.zip | |
lockdep: spin_lock_nest_lock()
Expose the new lock protection lock.
This can be used to annotate places where we take multiple locks of the
same class and avoid deadlocks by always taking another (top-level) lock
first.
NOTE: we're still bound to the MAX_LOCK_DEPTH (48) limit.
Signed-off-by: Peter Zijlstra <a.p.zijlstra@chello.nl>
Signed-off-by: Ingo Molnar <mingo@elte.hu>
Diffstat (limited to 'kernel')
| -rw-r--r-- | kernel/spinlock.c | 11 |
1 files changed, 11 insertions, 0 deletions
diff --git a/kernel/spinlock.c b/kernel/spinlock.c index a1fb54c93cdd..44baeea94ab9 100644 --- a/kernel/spinlock.c +++ b/kernel/spinlock.c @@ -292,6 +292,7 @@ void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass) } EXPORT_SYMBOL(_spin_lock_nested); + unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclass) { unsigned long flags; @@ -314,6 +315,16 @@ unsigned long __lockfunc _spin_lock_irqsave_nested(spinlock_t *lock, int subclas EXPORT_SYMBOL(_spin_lock_irqsave_nested); +void __lockfunc _spin_lock_nest_lock(spinlock_t *lock, + struct lockdep_map *nest_lock) +{ + preempt_disable(); + spin_acquire_nest(&lock->dep_map, 0, 0, nest_lock, _RET_IP_); + LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock); +} + +EXPORT_SYMBOL(_spin_lock_nest_lock); + #endif void __lockfunc _spin_unlock(spinlock_t *lock) |