[PATCH V2 1/3] Factor out #ifdef's from kernel/spinlock.c to

Petr Tesarik
2008-10-23T16:06:01Z

The new macro LOCK_CONTENDED_FLAGS expands to the correct implementation
depending on the config options, so that IRQ's are re-enabled when
possible, but they remain disabled if CONFIG_LOCKDEP is set.

Signed-off-by: Petr Tesarik <ptesarik@suse.cz>
---
include/linux/lockdep.h | 17 +++++++++++++++++
kernel/spinlock.c | 12 ++----------
2 files changed, 19 insertions(+), 10 deletions(-)

diff --git a/include/linux/lockdep.h b/include/linux/lockdep.h
index 331e5f1..1e6e578 100644
--- a/include/linux/lockdep.h
+++ b/include/linux/lockdep.h
@@ -376,6 +376,23 @@ do
{ \

#endif /* CONFIG_LOCK_STAT */

+#ifdef CONFIG_LOCKDEP
+
+/*
+ * On lockdep we dont want the hand-coded irq-enable of
+ * _raw_*_lock_flags() code, because lockdep assumes
+ * that interrupts are not re-enabled during lock-acquire:
+ */
+#define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \
+ LOCK_CONTENDED((_lock), (try), (lock))
+
+#else /* CONFIG_LOCKDEP */
+
+#define LOCK_CONTENDED_FLAGS(_lock, try, lock, lockfl, flags) \
+ lockfl((_lock), (flags))
+
+#endif /* CONFIG_LOCKDEP */
+
#if defined(CONFIG_TRACE_IRQFLAGS) && defined(CONFIG_GENERIC_HARDIRQS)
extern void early_init_irq_lock_class(void);
#else
diff --git a/kernel/spinlock.c b/kernel/spinlock.c
index 29ab207..cf41b87 100644
--- a/kernel/spinlock.c
+++ b/kernel/spinlock.c
@@ -299,16 +299,8 @@ unsigned long __lockfunc
_spin_lock_irqsave_nested(spinlock_t *lock, int subclas
local_irq_save(flags);
preempt_disable();
spin_acquire(&lock->dep_map, subclass, 0, _RET_IP_);
- /*
- * On lockdep we dont want the hand-coded irq-enable of
- * _raw_spin_lock_flags() code, because lockdep assumes
- * that interrupts are not re-enabled during lock-acquire:
- */
-#ifdef CONFIG_LOCKDEP
- LOCK_CONTENDED(lock, _raw_spin_trylock, _raw_spin_lock);
-#else
- _raw_spin_lock_flags(lock, &flags);
-#endif
+ LOCK_CONTENDED_FLAGS(lock, _raw_spin_trylock, _raw_spin_lock,
+ _raw_spin_lock_flags, &flags);
return flags;
}
EXPORT_SYMBOL(_spin_lock_irqsave_nested);