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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 | |
| parent | 7531e2f34d1d551b096143f19111139f0dd84c8b (diff) | |
| download | kernel_samsung_smdk4412-b7d39aff91454f2534db2275f55908656ec0470c.tar.gz kernel_samsung_smdk4412-b7d39aff91454f2534db2275f55908656ec0470c.tar.bz2 kernel_samsung_smdk4412-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>
| -rw-r--r-- | include/linux/lockdep.h | 2 | ||||
| -rw-r--r-- | include/linux/spinlock.h | 6 | ||||
| -rw-r--r-- | include/linux/spinlock_api_smp.h | 2 | ||||
| -rw-r--r-- | kernel/spinlock.c | 11 |
4 files changed, 21 insertions, 0 deletions
diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h index 93a8cc02a03..4452c04a7f6 100644 --- a/include/linux/lockdep.h +++ b/include/linux/lockdep.h @@ -410,8 +410,10 @@ static inline void print_irqtrace_events(struct task_struct *curr) #ifdef CONFIG_DEBUG_LOCK_ALLOC # ifdef CONFIG_PROVE_LOCKING # define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 2, NULL, i) +# define spin_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 2, n, i) # else # define spin_acquire(l, s, t, i) lock_acquire(l, s, t, 0, 1, NULL, i) +# define spin_acquire_nest(l, s, t, n, i) lock_acquire(l, s, t, 0, 1, NULL, i) # endif # define spin_release(l, n, i) lock_release(l, n, i) #else diff --git a/include/linux/spinlock.h b/include/linux/spinlock.h index 61e5610ad16..e0c0fccced4 100644 --- a/include/linux/spinlock.h +++ b/include/linux/spinlock.h @@ -183,8 +183,14 @@ do { \ #ifdef CONFIG_DEBUG_LOCK_ALLOC # define spin_lock_nested(lock, subclass) _spin_lock_nested(lock, subclass) +# define spin_lock_nest_lock(lock, nest_lock) \ + do { \ + typecheck(struct lockdep_map *, &(nest_lock)->dep_map);\ + _spin_lock_nest_lock(lock, &(nest_lock)->dep_map); \ + } while (0) #else # define spin_lock_nested(lock, subclass) _spin_lock(lock) +# define spin_lock_nest_lock(lock, nest_lock) _spin_lock(lock) #endif #define write_lock(lock) _write_lock(lock) diff --git a/include/linux/spinlock_api_smp.h b/include/linux/spinlock_api_smp.h index 8a2307ce729..d79845d034b 100644 --- a/include/linux/spinlock_api_smp.h +++ b/include/linux/spinlock_api_smp.h @@ -22,6 +22,8 @@ int in_lock_functions(unsigned long addr); void __lockfunc _spin_lock(spinlock_t *lock) __acquires(lock); void __lockfunc _spin_lock_nested(spinlock_t *lock, int subclass) __acquires(lock); +void __lockfunc _spin_lock_nest_lock(spinlock_t *lock, struct lockdep_map *map) + __acquires(lock); void __lockfunc _read_lock(rwlock_t *lock) __acquires(lock); void __lockfunc _write_lock(rwlock_t *lock) __acquires(lock); void __lockfunc _spin_lock_bh(spinlock_t *lock) __acquires(lock); diff --git a/kernel/spinlock.c b/kernel/spinlock.c index a1fb54c93cd..44baeea94ab 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) |