Tell hellgrind about header spinlock vs busy_mutex in the same order as in _starpu_data_check_not_busy

src/datawizard/interfaces/data_interface.c

@@ -674,16 +674,14 @@ static void _starpu_data_unregister(starpu_data_handle_t handle, unsigned cohere
 	_starpu_spin_unlock(&handle->header_lock);
 
 	/* Wait for all requests to finish (notably WT requests) */
+	/* Note: we here tell valgrind that reading busy_count is as
+	 * safe is if we had the lock held */
+	_STARPU_VALGRIND_HG_SPIN_LOCK_PRE(&handle->header_lock);
+	_STARPU_VALGRIND_HG_SPIN_LOCK_POST(&handle->header_lock);
 	STARPU_PTHREAD_MUTEX_LOCK(&handle->busy_mutex);
 	while (1) {
 		int busy;
-		/* Note: we here tell valgrind that reading busy_count is as
-		 * safe is if we had the lock held */
-		_STARPU_VALGRIND_HG_SPIN_LOCK_PRE(&handle->header_lock);
-		_STARPU_VALGRIND_HG_SPIN_LOCK_POST(&handle->header_lock);
 		busy = handle->busy_count;
-		_STARPU_VALGRIND_HG_SPIN_UNLOCK_PRE(&handle->header_lock);
-		_STARPU_VALGRIND_HG_SPIN_UNLOCK_POST(&handle->header_lock);
 		if (!busy)
 			break;
 		/* This is woken by _starpu_data_check_not_busy, always called
@@ -691,6 +689,8 @@ static void _starpu_data_unregister(starpu_data_handle_t handle, unsigned cohere
 		STARPU_PTHREAD_COND_WAIT(&handle->busy_cond, &handle->busy_mutex);
 	}
 	STARPU_PTHREAD_MUTEX_UNLOCK(&handle->busy_mutex);
+	_STARPU_VALGRIND_HG_SPIN_UNLOCK_PRE(&handle->header_lock);
+	_STARPU_VALGRIND_HG_SPIN_UNLOCK_POST(&handle->header_lock);
 
 	/* Wait for finished requests to release the handle */
 	_starpu_spin_lock(&handle->header_lock);