linux 2.6.16.38 w/ vs2.0.3-rc1

[linux-2.6.git] / lib / rwsem-spinlock.c

diff --git a/lib/rwsem-spinlock.c b/lib/rwsem-spinlock.c
index c4cfd6c..40ffde9 100644 (file)
--- a/lib/rwsem-spinlock.c
+++ b/lib/rwsem-spinlock.c
@@ -17,22 +17,27 @@ struct rwsem_waiter {
 #define RWSEM_WAITING_FOR_WRITE        0x00000002
 };
 
+#if RWSEM_DEBUG
+void rwsemtrace(struct rw_semaphore *sem, const char *str)
+{
+       if (sem->debug)
+               printk("[%d] %s({%d,%d})\n",
+                      current->pid, str, sem->activity,
+                      list_empty(&sem->wait_list) ? 0 : 1);
+}
+#endif
+
 /*
  * initialise the semaphore
  */
-void __init_rwsem(struct rw_semaphore *sem, const char *name,
-                 struct lock_class_key *key)
+void fastcall init_rwsem(struct rw_semaphore *sem)
 {
-#ifdef CONFIG_DEBUG_LOCK_ALLOC
-       /*
-        * Make sure we are not reinitializing a held semaphore:
-        */
-       debug_check_no_locks_freed((void *)sem, sizeof(*sem));
-       lockdep_init_map(&sem->dep_map, name, key, 0);
-#endif
        sem->activity = 0;
        spin_lock_init(&sem->wait_lock);
        INIT_LIST_HEAD(&sem->wait_list);
+#if RWSEM_DEBUG
+       sem->debug = 0;
+#endif
 }
 
 /*
@@ -51,6 +56,8 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)
        struct task_struct *tsk;
        int woken;
 
+       rwsemtrace(sem, "Entering __rwsem_do_wake");
+
        waiter = list_entry(sem->wait_list.next, struct rwsem_waiter, list);
 
        if (!wakewrite) {
@@ -97,6 +104,7 @@ __rwsem_do_wake(struct rw_semaphore *sem, int wakewrite)
        sem->activity += woken;
 
  out:
+       rwsemtrace(sem, "Leaving __rwsem_do_wake");
        return sem;
 }
 
@@ -130,6 +138,8 @@ void fastcall __sched __down_read(struct rw_semaphore *sem)
        struct rwsem_waiter waiter;
        struct task_struct *tsk;
 
+       rwsemtrace(sem, "Entering __down_read");
+
        spin_lock_irq(&sem->wait_lock);
 
        if (sem->activity >= 0 && list_empty(&sem->wait_list)) {
@@ -161,8 +171,9 @@ void fastcall __sched __down_read(struct rw_semaphore *sem)
        }
 
        tsk->state = TASK_RUNNING;
+
  out:
-       ;
+       rwsemtrace(sem, "Leaving __down_read");
 }
 
 /*
@@ -173,6 +184,7 @@ int fastcall __down_read_trylock(struct rw_semaphore *sem)
        unsigned long flags;
        int ret = 0;
 
+       rwsemtrace(sem, "Entering __down_read_trylock");
 
        spin_lock_irqsave(&sem->wait_lock, flags);
 
@@ -184,6 +196,7 @@ int fastcall __down_read_trylock(struct rw_semaphore *sem)
 
        spin_unlock_irqrestore(&sem->wait_lock, flags);
 
+       rwsemtrace(sem, "Leaving __down_read_trylock");
        return ret;
 }
 
@@ -191,11 +204,13 @@ int fastcall __down_read_trylock(struct rw_semaphore *sem)
  * get a write lock on the semaphore
  * - we increment the waiting count anyway to indicate an exclusive lock
  */
-void fastcall __sched __down_write_nested(struct rw_semaphore *sem, int subclass)
+void fastcall __sched __down_write(struct rw_semaphore *sem)
 {
        struct rwsem_waiter waiter;
        struct task_struct *tsk;
 
+       rwsemtrace(sem, "Entering __down_write");
+
        spin_lock_irq(&sem->wait_lock);
 
        if (sem->activity == 0 && list_empty(&sem->wait_list)) {
@@ -227,13 +242,9 @@ void fastcall __sched __down_write_nested(struct rw_semaphore *sem, int subclass
        }
 
        tsk->state = TASK_RUNNING;
- out:
-       ;
-}
 
-void fastcall __sched __down_write(struct rw_semaphore *sem)
-{
-       __down_write_nested(sem, 0);
+ out:
+       rwsemtrace(sem, "Leaving __down_write");
 }
 
 /*
@@ -244,6 +255,8 @@ int fastcall __down_write_trylock(struct rw_semaphore *sem)
        unsigned long flags;
        int ret = 0;
 
+       rwsemtrace(sem, "Entering __down_write_trylock");
+
        spin_lock_irqsave(&sem->wait_lock, flags);
 
        if (sem->activity == 0 && list_empty(&sem->wait_list)) {
@@ -254,6 +267,7 @@ int fastcall __down_write_trylock(struct rw_semaphore *sem)
 
        spin_unlock_irqrestore(&sem->wait_lock, flags);
 
+       rwsemtrace(sem, "Leaving __down_write_trylock");
        return ret;
 }
 
@@ -264,12 +278,16 @@ void fastcall __up_read(struct rw_semaphore *sem)
 {
        unsigned long flags;
 
+       rwsemtrace(sem, "Entering __up_read");
+
        spin_lock_irqsave(&sem->wait_lock, flags);
 
        if (--sem->activity == 0 && !list_empty(&sem->wait_list))
                sem = __rwsem_wake_one_writer(sem);
 
        spin_unlock_irqrestore(&sem->wait_lock, flags);
+
+       rwsemtrace(sem, "Leaving __up_read");
 }
 
 /*
@@ -279,6 +297,8 @@ void fastcall __up_write(struct rw_semaphore *sem)
 {
        unsigned long flags;
 
+       rwsemtrace(sem, "Entering __up_write");
+
        spin_lock_irqsave(&sem->wait_lock, flags);
 
        sem->activity = 0;
@@ -286,6 +306,8 @@ void fastcall __up_write(struct rw_semaphore *sem)
                sem = __rwsem_do_wake(sem, 1);
 
        spin_unlock_irqrestore(&sem->wait_lock, flags);
+
+       rwsemtrace(sem, "Leaving __up_write");
 }
 
 /*
@@ -296,6 +318,8 @@ void fastcall __downgrade_write(struct rw_semaphore *sem)
 {
        unsigned long flags;
 
+       rwsemtrace(sem, "Entering __downgrade_write");
+
        spin_lock_irqsave(&sem->wait_lock, flags);
 
        sem->activity = 1;
@@ -303,14 +327,18 @@ void fastcall __downgrade_write(struct rw_semaphore *sem)
                sem = __rwsem_do_wake(sem, 0);
 
        spin_unlock_irqrestore(&sem->wait_lock, flags);
+
+       rwsemtrace(sem, "Leaving __downgrade_write");
 }
 
-EXPORT_SYMBOL(__init_rwsem);
+EXPORT_SYMBOL(init_rwsem);
 EXPORT_SYMBOL(__down_read);
 EXPORT_SYMBOL(__down_read_trylock);
-EXPORT_SYMBOL(__down_write_nested);
 EXPORT_SYMBOL(__down_write);
 EXPORT_SYMBOL(__down_write_trylock);
 EXPORT_SYMBOL(__up_read);
 EXPORT_SYMBOL(__up_write);
 EXPORT_SYMBOL(__downgrade_write);
+#if RWSEM_DEBUG
+EXPORT_SYMBOL(rwsemtrace);
+#endif