rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...0: (1 GPs behind) idle=36ec/1/0x4000000000000000 softirq=6589/6590 fqs=9960
	(detected by 1, t=30504 jiffies, g=14713, q=4 ncpus=2)
Task dump for CPU 0:
task:cmp             state:R  running task     stack:0     pid:2746  ppid:2744   flags:0x00000008
Call Trace:
[<ffffffff834348b8>] context_switch kernel/sched/core.c:5244 [inline]
[<ffffffff834348b8>] __schedule+0x624/0x1254 kernel/sched/core.c:6555
rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...0: (1 GPs behind) idle=36ec/1/0x4000000000000000 softirq=6589/6590 fqs=28261
	(detected by 1, t=122009 jiffies, g=14713, q=4 ncpus=2)
Task dump for CPU 0:
task:cmp             state:R  running task     stack:0     pid:2746  ppid:2744   flags:0x00000008
Call Trace:
[<ffffffff834348b8>] context_switch kernel/sched/core.c:5244 [inline]
[<ffffffff834348b8>] __schedule+0x624/0x1254 kernel/sched/core.c:6555