task = get_pid_task(submit->pid, PIDTYPE_PID);
                if (task) {
                        comm = kstrdup(task->comm, GFP_KERNEL);
-
-                       /*
-                        * So slightly annoying, in other paths like
-                        * mmap'ing gem buffers, mmap_sem is acquired
-                        * before struct_mutex, which means we can't
-                        * hold struct_mutex across the call to
-                        * get_cmdline().  But submits are retired
-                        * from the same in-order workqueue, so we can
-                        * safely drop the lock here without worrying
-                        * about the submit going away.
-                        */
-                       mutex_unlock(&dev->struct_mutex);
                        cmd = kstrdup_quotable_cmdline(task, GFP_KERNEL);
                        put_task_struct(task);
-                       mutex_lock(&dev->struct_mutex);
                }
 
                if (comm && cmd) {