This switch the core over to the architecture defined fast path locking
primitives. It also adds __mutex_lock_interruptible_noinline and
friends.
Index: linux-2.6/kernel/mutex.c
===================================================================
--- linux-2.6.orig/kernel/mutex.c
+++ linux-2.6/kernel/mutex.c
@@ -266,13 +266,8 @@ __mutex_lock_interruptible_nonatomic(str
*/
int fastcall mutex_trylock(struct mutex *lock)
{
-#ifdef __HAVE_ARCH_CMPXCHG
if (atomic_cmpxchg(&lock->count, 1, 0) == 1)
return 1;
-#else
- if (atomic_dec_return(&lock->count) == 0)
- return 1;
-#endif
return 0;
}
@@ -316,13 +311,14 @@ static inline void __mutex_unlock_nonato
* Waiters take care of themselves and stay in flight until
* necessary.
*
- * (in the xchg based implementation the fastpath has set the
+ * (depending on the implementation the fastpath has set the
* count to 1 already, so we must not set it here, because we
* dont own the lock anymore. In the debug case we must set
* the lock inside the spinlock.)
*/
-#if !defined(CONFIG_MUTEX_XCHG_ALGORITHM) && !defined(CONFIG_DEBUG_MUTEXES)
- atomic_set(&lock->count, 1);
+#if !defined(CONFIG_DEBUG_MUTEXES)
+ if (__mutex_slowpath_needs_unlock())
+ atomic_set(&lock->count, 1);
#endif
spin_lock_mutex(&lock->wait_lock);
#ifdef CONFIG_DEBUG_MUTEXES
@@ -349,21 +345,12 @@ static inline void __mutex_unlock_nonato
static __sched void FASTCALL(__mutex_lock_noinline(atomic_t *lock_count));
/*
- * Some architectures do not have fast dec_and_test atomic primitives,
- * for them we are providing an atomic_xchg() based mutex implementation,
- * if they enable CONFIG_MUTEX_XCHG_ALGORITHM.
- *
* The locking fastpath is the 1->0 transition from 'unlocked' into
* 'locked' state:
*/
static inline void __mutex_lock_atomic(struct mutex *lock)
{
-#ifdef CONFIG_MUTEX_XCHG_ALGORITHM
- if (unlikely(atomic_xchg(&lock->count, 0) != 1))
- __mutex_lock_noinline(&lock->count);
-#else
- atomic_dec_call_if_negative(&lock->count, __mutex_lock_noinline);
-#endif
+ __mutex_fastpath_lock(&lock->count, __mutex_lock_noinline);
}
/*
@@ -383,16 +370,23 @@ static inline void __mutex_lock(struct m
__mutex_lock_atomic(lock);
}
+static __sched int FASTCALL(__mutex_lock_interruptible_noinline(atomic_t *lock_count));
+
+static int __mutex_lock_interruptible_atomic(struct mutex *lock)
+{
+ __mutex_fastpath_lock_retval(&lock->count, __mutex_lock_interruptible_noinline);
+}
+
+static int fastcall __sched __mutex_lock_interruptible_noinline(atomic_t *lock_count)
+{
+ struct mutex *lock = container_of(lock_count, struct mutex, count);
+
+ return __mutex_lock_interruptible_nonatomic(lock);
+}
+
static inline int __mutex_lock_interruptible(struct mutex *lock)
{
-#ifdef CONFIG_MUTEX_XCHG_ALGORITHM
- if (unlikely(atomic_xchg(&lock->count, 0) != 1))
- return __mutex_lock_interruptible_nonatomic(lock);
-#else
- if (unlikely(atomic_dec_return(&lock->count) < 0))
- return __mutex_lock_interruptible_nonatomic(lock);
-#endif
- return 0;
+ __mutex_lock_interruptible_atomic(lock);
}
static void __sched FASTCALL(__mutex_unlock_noinline(atomic_t *lock_count));
@@ -403,12 +397,7 @@ static void __sched FASTCALL(__mutex_unl
*/
static inline void __mutex_unlock_atomic(struct mutex *lock)
{
-#ifdef CONFIG_MUTEX_XCHG_ALGORITHM
- if (unlikely(atomic_xchg(&lock->count, 1) != 0))
- __mutex_unlock_noinline(&lock->count);
-#else
- atomic_inc_call_if_nonpositive(&lock->count, __mutex_unlock_noinline);
-#endif
+ __mutex_fastpath_unlock(&lock->count, __mutex_unlock_noinline);
}
static void fastcall __sched __mutex_unlock_noinline(atomic_t *lock_count)
Index: linux-2.6/include/linux/mutex.h
===================================================================
--- linux-2.6.orig/include/linux/mutex.h
+++ linux-2.6/include/linux/mutex.h
@@ -12,6 +12,7 @@
*/
#include <linux/list.h>
#include <linux/spinlock_types.h>
+#include <asm/mutex.h>
#include <asm/atomic.h>
-
To unsubscribe from this list: send the line "unsubscribe linux-kernel" in
the body of a message to [email protected]
More majordomo info at http://vger.kernel.org/majordomo-info.html
Please read the FAQ at http://www.tux.org/lkml/
[Index of Archives]
[Kernel Newbies]
[Netfilter]
[Bugtraq]
[Photo]
[Stuff]
[Gimp]
[Yosemite News]
[MIPS Linux]
[ARM Linux]
[Linux Security]
[Linux RAID]
[Video 4 Linux]
[Linux for the blind]
[Linux Resources]
