rcu: INFO: rcu_preempt detected expedited stalls on CPUs/tasks: { 0-... } 6 jiffies s: 7221 root: 0x1/.
rcu: blocking rcu_node structures (internal RCU debug):
Task dump for CPU 0:
task:swapper/0       state:R  running task     stack:28544 pid:    0 ppid:     0 flags:0x00004008
Call Trace:
 <TASK>
 </TASK>