Kernel panic - not syncing: softlockup: hung tasks / watchdog thread unable to run due to throttled real-time run queue

Issue

• The watchdog thread is unable to run due to a throttled real-time run queue and as a result a softlockup is reported
• A high se.exec_max value (e.g. 54.7 seconds) can erroneously cause throttling of the real-time run queue
• The high se.exec_max value is a side-effect of something pathological happening in the thread that was running on the same CPU prior to the affected real-time thread