The LNet router checker thread wakes up every second to see if a ping needs to be sent to any of the configured routers.  If router pings are turned off, it does not wake.

This has caused confusion to people who analyze Lustre/LNet using tools like vtune as then see us waking up every second even when there is no file system traffic.

Theoretically, we should be keeping the router list in a sorted order of when the next ping needs to be sent.  Then, the router_check should sleep until the next ping time and not every second.