Logger usage

I've browsing jnode source code, and found some strange usage of log4j's Logger. I think the logger should be used in a static way - declared as:
private final static Logger log = LogManager(ThisClass.class);
But instead of this, in the network layer, there are several places, where it's declared as a not-static variable. (TCPSocketImpl,TCPHeader,TCPOutChannel,...) I think it can cause a big performance degradation, without any gain.