We only attempt to rebias when calling revoke_and_rebias() from ObjectSynchronizer::fast_enter() after failing to grab the lock in the interpreter or compiler code. In all other places we pass false for that argument. In any case, rebiasing will only succeed in cases where we end up in a bulk rebiasing operation which is not common. Another case where rebiasing could succeed is if we try to revoke with a handshake but it fails and we need to loop again, but that's even less common.