[PATCH] lockdep: clean up rwsems

Clean up rwsems. Signed-off-by: Ingo Molnar <mingo@elte.hu> Signed-off-by: Andrew Morton <akpm@osdl.org> Signed-off-by: Linus Torvalds <torvalds@osdl.org>
Intel-BMC · Jul 3, 2006 · c4e0511 · c4e0511
1 parent 8b3db9c
commit c4e0511
Show file tree

Hide file tree

Showing 6 changed files with 109 additions and 128 deletions.
diff --git a/include/asm-i386/rwsem.h b/include/asm-i386/rwsem.h
@@ -61,23 +61,11 @@ struct rw_semaphore {
 #define RWSEM_ACTIVE_WRITE_BIAS		(RWSEM_WAITING_BIAS + RWSEM_ACTIVE_BIAS)
 	spinlock_t		wait_lock;
 	struct list_head	wait_list;
-#if RWSEM_DEBUG
-	int			debug;
-#endif
 };
 
-/*
- * initialisation
- */
-#if RWSEM_DEBUG
-#define __RWSEM_DEBUG_INIT      , 0
-#else
-#define __RWSEM_DEBUG_INIT	/* */
-#endif
-
 #define __RWSEM_INITIALIZER(name) \
 { RWSEM_UNLOCKED_VALUE, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) \
-	__RWSEM_DEBUG_INIT }
+	}
 
 #define DECLARE_RWSEM(name) \
 	struct rw_semaphore name = __RWSEM_INITIALIZER(name)
@@ -87,9 +75,6 @@ static inline void init_rwsem(struct rw_semaphore *sem)
 	sem->count = RWSEM_UNLOCKED_VALUE;
 	spin_lock_init(&sem->wait_lock);
 	INIT_LIST_HEAD(&sem->wait_list);
-#if RWSEM_DEBUG
-	sem->debug = 0;
-#endif
 }
 
 /*

diff --git a/include/linux/rwsem-spinlock.h b/include/linux/rwsem-spinlock.h
@@ -32,22 +32,10 @@ struct rw_semaphore {
 	__s32			activity;
 	spinlock_t		wait_lock;
 	struct list_head	wait_list;
-#if RWSEM_DEBUG
-	int			debug;
-#endif
 };
 
-/*
- * initialisation
- */
-#if RWSEM_DEBUG
-#define __RWSEM_DEBUG_INIT      , 0
-#else
-#define __RWSEM_DEBUG_INIT	/* */
-#endif
-
 #define __RWSEM_INITIALIZER(name) \
-{ 0, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) __RWSEM_DEBUG_INIT }
+{ 0, SPIN_LOCK_UNLOCKED, LIST_HEAD_INIT((name).wait_list) }
 
 #define DECLARE_RWSEM(name) \
 	struct rw_semaphore name = __RWSEM_INITIALIZER(name)

diff --git a/include/linux/rwsem.h b/include/linux/rwsem.h
@@ -9,8 +9,6 @@
 
 #include <linux/linkage.h>
 
-#define RWSEM_DEBUG 0
-
 #ifdef __KERNEL__
 
 #include <linux/types.h>
@@ -26,23 +24,13 @@ struct rw_semaphore;
 #include <asm/rwsem.h> /* use an arch-specific implementation */
 #endif
 
-#ifndef rwsemtrace
-#if RWSEM_DEBUG
-extern void FASTCALL(rwsemtrace(struct rw_semaphore *sem, const char *str));
-#else
-#define rwsemtrace(SEM,FMT)
-#endif
-#endif
-
 /*
  * lock for reading
  */
 static inline void down_read(struct rw_semaphore *sem)
 {
 	might_sleep();
-	rwsemtrace(sem,"Entering down_read");
 	__down_read(sem);
-	rwsemtrace(sem,"Leaving down_read");
 }
 
 /*
@@ -51,9 +39,7 @@ static inline void down_read(struct rw_semaphore *sem)
 static inline int down_read_trylock(struct rw_semaphore *sem)
 {
 	int ret;
-	rwsemtrace(sem,"Entering down_read_trylock");
 	ret = __down_read_trylock(sem);
-	rwsemtrace(sem,"Leaving down_read_trylock");
 	return ret;
 }
 
@@ -63,9 +49,7 @@ static inline int down_read_trylock(struct rw_semaphore *sem)
 static inline void down_write(struct rw_semaphore *sem)
 {
 	might_sleep();
-	rwsemtrace(sem,"Entering down_write");
 	__down_write(sem);
-	rwsemtrace(sem,"Leaving down_write");
 }
 
 /*
@@ -74,9 +58,7 @@ static inline void down_write(struct rw_semaphore *sem)
 static inline int down_write_trylock(struct rw_semaphore *sem)
 {
 	int ret;
-	rwsemtrace(sem,"Entering down_write_trylock");
 	ret = __down_write_trylock(sem);
-	rwsemtrace(sem,"Leaving down_write_trylock");
 	return ret;
 }
 
@@ -85,29 +67,23 @@ static inline int down_write_trylock(struct rw_semaphore *sem)
  */
 static inline void up_read(struct rw_semaphore *sem)
 {
-	rwsemtrace(sem,"Entering up_read");
 	__up_read(sem);
-	rwsemtrace(sem,"Leaving up_read");
 }
 
 /*
  * release a write lock
  */
 static inline void up_write(struct rw_semaphore *sem)
 {
-	rwsemtrace(sem,"Entering up_write");
 	__up_write(sem);
-	rwsemtrace(sem,"Leaving up_write");
 }
 
 /*
  * downgrade write lock to read lock
  */
 static inline void downgrade_write(struct rw_semaphore *sem)
 {
-	rwsemtrace(sem,"Entering downgrade_write");
 	__downgrade_write(sem);
-	rwsemtrace(sem,"Leaving downgrade_write");
 }
 
 #endif /* __KERNEL__ */

diff --git a/kernel/rwsem.c b/kernel/rwsem.c
@@ -0,0 +1,105 @@
+/* kernel/rwsem.c: R/W semaphores, public implementation
+ *
+ * Written by David Howells (dhowells@redhat.com).
+ * Derived from asm-i386/semaphore.h
+ */
+
+#include <linux/types.h>
+#include <linux/kernel.h>
+#include <linux/module.h>
+#include <linux/rwsem.h>
+
+#include <asm/system.h>
+#include <asm/atomic.h>
+
+/*
+ * lock for reading
+ */
+void down_read(struct rw_semaphore *sem)
+{
+	might_sleep();
+	rwsem_acquire_read(&sem->dep_map, 0, 0, _RET_IP_);
+
+	__down_read(sem);
+}
+
+EXPORT_SYMBOL(down_read);
+
+/*
+ * trylock for reading -- returns 1 if successful, 0 if contention
+ */
+int down_read_trylock(struct rw_semaphore *sem)
+{
+	int ret = __down_read_trylock(sem);
+
+	if (ret == 1)
+		rwsem_acquire_read(&sem->dep_map, 0, 1, _RET_IP_);
+	return ret;
+}
+
+EXPORT_SYMBOL(down_read_trylock);
+
+/*
+ * lock for writing
+ */
+void down_write(struct rw_semaphore *sem)
+{
+	might_sleep();
+	rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
+
+	__down_write(sem);
+}
+
+EXPORT_SYMBOL(down_write);
+
+/*
+ * trylock for writing -- returns 1 if successful, 0 if contention
+ */
+int down_write_trylock(struct rw_semaphore *sem)
+{
+	int ret = __down_write_trylock(sem);
+
+	if (ret == 1)
+		rwsem_acquire(&sem->dep_map, 0, 0, _RET_IP_);
+	return ret;
+}
+
+EXPORT_SYMBOL(down_write_trylock);
+
+/*
+ * release a read lock
+ */
+void up_read(struct rw_semaphore *sem)
+{
+	rwsem_release(&sem->dep_map, 1, _RET_IP_);
+
+	__up_read(sem);
+}
+
+EXPORT_SYMBOL(up_read);
+
+/*
+ * release a write lock
+ */
+void up_write(struct rw_semaphore *sem)
+{
+	rwsem_release(&sem->dep_map, 1, _RET_IP_);
+
+	__up_write(sem);
+}
+
+EXPORT_SYMBOL(up_write);
+
+/*
+ * downgrade write lock to read lock
+ */
+void downgrade_write(struct rw_semaphore *sem)
+{
+	/*
+	 * lockdep: a downgraded write will live on as a write
+	 * dependency.
+	 */
+	__downgrade_write(sem);
+}
+
+EXPORT_SYMBOL(downgrade_write);