rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	0-...!: (1 ticks this GP) idle=0164/1/0x40000002 softirq=71613/71613 fqs=14
rcu: 	(detected by 1, t=30004 jiffies, g=147833, q=374 ncpus=2)
Sending NMI from CPU 1 to CPUs 0:
After 10 seconds, these CPUS still haven't responded to the NMI: 0
rcu: rcu_preempt kthread starved for 29938 jiffies! g147833 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: 	Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior.
rcu: RCU grace-period kthread stack dump:
task:rcu_preempt     state:R  running task     stack:0     pid:15    tgid:15    ppid:2      task_flags:0x208040 flags:0x00000000
Call trace: 
[<81b5c75c>] (__schedule) from [<81b5dbf4>] (__schedule_loop kernel/sched/core.c:7311 [inline])
[<81b5c75c>] (__schedule) from [<81b5dbf4>] (schedule+0x2c/0xec kernel/sched/core.c:7326)
 r10:82af1358 r9:00000000 r8:83181880 r7:82a03d80 r6:83181880 r5:82a03d80
 r4:83181880
[<81b5dbc8>] (schedule) from [<81b65ed4>] (schedule_timeout+0x8c/0x114 kernel/time/sleep_timeout.c:99)
 r5:82a03d80 r4:0004542c
[<81b65e48>] (schedule_timeout) from [<80308398>] (rcu_gp_fqs_loop+0x10c/0x498 kernel/rcu/tree.c:2123)
 r6:00000001 r5:82af1180 r4:00000000
[<8030828c>] (rcu_gp_fqs_loop) from [<8030e6c0>] (rcu_gp_kthread+0xb8/0x13c kernel/rcu/tree.c:2325)
 r10:8232acb0 r9:df855f64 r8:82a03d80 r7:82af1180 r6:83181880 r5:82af135a
 r4:82af1358
[<8030e608>] (rcu_gp_kthread) from [<80281710>] (kthread+0x11c/0x154 kernel/kthread.c:436)
 r7:00000000
[<802815f4>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137)
Exception stack(0xdf855fb0 to 0xdf855ff8)
5fa0:                                     00000000 00000000 00000000 00000000
5fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:802815f4 r4:830f8440
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 21 Comm: migration/1 Tainted: G             L      syzkaller #0 PREEMPT 
Tainted: [L]=SOFTLOCKUP
Hardware name: ARM-Versatile Express
Stopper: multi_cpu_stop+0x0/0x170 kernel/stop_machine.c:198 <- __stop_cpus.constprop.0+0x68/0xa8
PC is at multi_cpu_stop+0xd8/0x170 kernel/stop_machine.c:228
LR is at multi_cpu_stop+0xd8/0x170 kernel/stop_machine.c:227
pc : [<8037f2ac>]    lr : [<8037f2ac>]    psr: 60000013
sp : df871ef0  ip : df871ef0  fp : df871f24
r10: 00000001  r9 : 00000000  r8 : 00000000
r7 : 82a0b150  r6 : dfbc5e04  r5 : 00000001  r4 : dfbc5e18
r3 : 00000001  r2 : 00000000  r1 : 00000008  r0 : 82a0b150
Flags: nZCv  IRQs on  FIQs on  Mode SVC_32  ISA ARM  Segment none
Control: 30c5387d  Table: 85da2740  DAC: 00000000
Call trace: 
[<8037f1d4>] (multi_cpu_stop) from [<8037ef64>] (cpu_stopper_thread+0x94/0x130 kernel/stop_machine.c:512)
 r10:8317bd40 r9:ddddc674 r8:dfbc5e04 r7:ddddc66c r6:8037f1d4 r5:ddddc668
 r4:dfbc5dcc
[<8037eed0>] (cpu_stopper_thread) from [<80289ffc>] (smpboot_thread_fn+0x108/0x2f0 kernel/smpboot.c:160)
 r10:00000000 r9:00000001 r8:00000000 r7:00000001 r6:82aff60c r5:8310b700
 r4:8317bd40
[<80289ef4>] (smpboot_thread_fn) from [<80281710>] (kthread+0x11c/0x154 kernel/kthread.c:436)
 r9:df819d28 r8:83003c80 r7:8310b700 r6:80289ef4 r5:8317bd40 r4:8310b600
[<802815f4>] (kthread) from [<80200114>] (ret_from_fork+0x14/0x20 arch/arm/kernel/entry-common.S:137)
Exception stack(0xdf871fb0 to 0xdf871ff8)
1fa0:                                     00000000 00000000 00000000 00000000
1fc0: 00000000 00000000 00000000 00000000 00000000 00000000 00000000 00000000
1fe0: 00000000 00000000 00000000 00000000 00000013 00000000
 r9:00000000 r8:00000000 r7:00000000 r6:00000000 r5:802815f4 r4:8310b600