[PATCH] add sem_is_read/write_locked()

Add sem_is_read/write_locked functions to the read/write semaphores, along the same lines of the *_is_locked spinlock functions. The swap token tuning patch uses sem_is_read_locked; sem_is_write_locked is added for completeness. Signed-off-by: Rik van Riel <[email protected]> Signed-off-by: Andrew Morton <[email protected]> Signed-off-by: Linus Torvalds <[email protected]>
Baughn · Oct 30, 2005 · eb92f4e · eb92f4e
1 parent 63f324c
commit eb92f4e
Show file tree

Hide file tree

Showing 10 changed files with 50 additions and 0 deletions.
diff --git a/include/asm-alpha/rwsem.h b/include/asm-alpha/rwsem.h
@@ -262,5 +262,10 @@ static inline long rwsem_atomic_update(long val, struct rw_semaphore *sem)
 #endif
 }
 
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return (sem->count != 0);
+}
+
 #endif /* __KERNEL__ */
 #endif /* _ALPHA_RWSEM_H */
diff --git a/include/asm-i386/rwsem.h b/include/asm-i386/rwsem.h
@@ -284,5 +284,10 @@ LOCK_PREFIX	"xadd %0,(%2)"
 	return tmp+delta;
 }
 
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return (sem->count != 0);
+}
+
 #endif /* __KERNEL__ */
 #endif /* _I386_RWSEM_H */
diff --git a/include/asm-ia64/rwsem.h b/include/asm-ia64/rwsem.h
@@ -186,4 +186,9 @@ __downgrade_write (struct rw_semaphore *sem)
 #define rwsem_atomic_add(delta, sem)	atomic64_add(delta, (atomic64_t *)(&(sem)->count))
 #define rwsem_atomic_update(delta, sem)	atomic64_add_return(delta, (atomic64_t *)(&(sem)->count))
 
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return (sem->count != 0);
+}
+
 #endif /* _ASM_IA64_RWSEM_H */
diff --git a/include/asm-ppc/rwsem.h b/include/asm-ppc/rwsem.h
@@ -168,5 +168,10 @@ static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
 	return atomic_add_return(delta, (atomic_t *)(&sem->count));
 }
 
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return (sem->count != 0);
+}
+
 #endif /* __KERNEL__ */
 #endif /* _PPC_RWSEM_XADD_H */
diff --git a/include/asm-ppc64/rwsem.h b/include/asm-ppc64/rwsem.h
@@ -163,5 +163,10 @@ static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
 	return atomic_add_return(delta, (atomic_t *)(&sem->count));
 }
 
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return (sem->count != 0);
+}
+
 #endif /* __KERNEL__ */
 #endif /* _PPC_RWSEM_XADD_H */
diff --git a/include/asm-s390/rwsem.h b/include/asm-s390/rwsem.h
@@ -351,5 +351,10 @@ static inline long rwsem_atomic_update(long delta, struct rw_semaphore *sem)
 	return new;
 }
 
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return (sem->count != 0);
+}
+
 #endif /* __KERNEL__ */
 #endif /* _S390_RWSEM_H */
diff --git a/include/asm-sh/rwsem.h b/include/asm-sh/rwsem.h
@@ -166,5 +166,10 @@ static inline int rwsem_atomic_update(int delta, struct rw_semaphore *sem)
 	return atomic_add_return(delta, (atomic_t *)(&sem->count));
 }
 
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return (sem->count != 0);
+}
+
 #endif /* __KERNEL__ */
 #endif /* _ASM_SH_RWSEM_H */
diff --git a/include/asm-sparc64/rwsem.h b/include/asm-sparc64/rwsem.h
@@ -56,6 +56,11 @@ static inline void rwsem_atomic_add(int delta, struct rw_semaphore *sem)
 	atomic_add(delta, (atomic_t *)(&sem->count));
 }
 
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return (sem->count != 0);
+}
+
 #endif /* __KERNEL__ */
 
 #endif /* _SPARC64_RWSEM_H */
diff --git a/include/asm-x86_64/rwsem.h b/include/asm-x86_64/rwsem.h
@@ -274,5 +274,10 @@ LOCK_PREFIX	"xaddl %0,(%2)"
 	return tmp+delta;
 }
 
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return (sem->count != 0);
+}
+
 #endif /* __KERNEL__ */
 #endif /* _X8664_RWSEM_H */
diff --git a/include/linux/rwsem-spinlock.h b/include/linux/rwsem-spinlock.h
@@ -61,5 +61,10 @@ extern void FASTCALL(__up_read(struct rw_semaphore *sem));
 extern void FASTCALL(__up_write(struct rw_semaphore *sem));
 extern void FASTCALL(__downgrade_write(struct rw_semaphore *sem));
 
+static inline int rwsem_is_locked(struct rw_semaphore *sem)
+{
+	return (sem->activity != 0);
+}
+
 #endif /* __KERNEL__ */
 #endif /* _LINUX_RWSEM_SPINLOCK_H */