graph_lock
if (!graph_lock())
if (!graph_lock()) {
if (!graph_lock()) {
if (!graph_lock())
if (!graph_lock())
locked = graph_lock();
static DEFINE_MUTEX(graph_lock);
mutex_lock(&graph_lock);
lockdep_is_held(&graph_lock));
lockdep_is_held(&graph_lock));
mutex_unlock(&graph_lock);
mutex_lock(&graph_lock);
lockdep_is_held(&graph_lock));
mutex_unlock(&graph_lock);
mutex_lock(&graph_lock);
lockdep_is_held(&graph_lock));
mutex_unlock(&graph_lock);
mutex_lock(&graph_lock);
lockdep_is_held(&graph_lock));
lockdep_is_held(&graph_lock));
mutex_unlock(&graph_lock);