file: /proc/sys/kernel/panic_on_rcu_stall
variable: kernel.panic_on_rcu_stall
Official reference

When set to 1, calls panic() after RCU stall detection messages. This is useful to define the root cause of RCU stalls using a vmcore.

0: do not panic() when RCU stall takes place, default behavior.

1: panic() after printing RCU stall messages.