rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 1-... } 10507 jiffies s: 47213 root: 0x2/. rcu: blocking rcu_node structures (internal RCU debug): Task dump for CPU 1: task:ksoftirqd/1 state:R running task stack:25592 pid: 19 ppid: 2 flags:0x00004008 Call Trace: