rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	0-...!: (1 ticks this GP) idle=c46/1/0x4000000000000004 softirq=52268/52268 fqs=0 
	(t=30000 jiffies g=67553 q=336)
rcu: rcu_preempt kthread starved for 30000 jiffies! g67553 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I28952    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3384 [inline]
 __schedule+0x74b/0xb80 kernel/sched/core.c:4069
 schedule+0x131/0x1e0 kernel/sched/core.c:4136
 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1639 [inline]
 rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1799
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 0
CPU: 0 PID: 24155 Comm: kworker/0:1 Not tainted 5.4.0-rc3+ #0
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Workqueue: rcu_gp process_srcu
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x1d8/0x2f8 lib/dump_stack.c:113
 nmi_cpu_backtrace+0xaf/0x1a0 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x174/0x290 lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x10/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x15a/0x220 kernel/rcu/tree_stall.h:254
 print_cpu_stall kernel/rcu/tree_stall.h:455 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:529 [inline]
 rcu_pending kernel/rcu/tree.c:2795 [inline]
 rcu_sched_clock_irq+0xe22/0x1ae0 kernel/rcu/tree.c:2244
 update_process_times+0x12d/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1299
 __run_hrtimer kernel/time/hrtimer.c:1514 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:830
RIP: 0010:ffs arch/x86/include/asm/paravirt.h:766 [inline]
RIP: 0010:__do_softirq+0x1ed/0x7c4 kernel/softirq.c:280
Code: 80 3c 38 00 74 0c 48 c7 c7 00 92 8a 88 e8 0b 76 0c fa 48 83 3d 23 90 ea 00 00 0f 84 dd 05 00 00 0f b7 cb fb 66 0f 1f 44 00 00 <89> 4d 88 b8 ff ff ff ff 0f bc 45 88 41 89 c6 41 ff c6 0f 84 72 01
RSP: 0018:ffff8880aea09ec0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff1115240 RBX: 0000000004200008 RCX: 0000000000000008
RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff88809059ef04
RBP: ffff8880aea09f80 R08: ffff88809059ef18 R09: fffffbfff12bc0a2
R10: fffffbfff12bc0a2 R11: 0000000000000000 R12: ffff88809059e6c0
R13: dffffc0000000000 R14: 0000000000000000 R15: dffffc0000000000
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x227/0x230 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 do_IRQ+0x100/0x1e0 arch/x86/kernel/irq.c:263
 common_interrupt+0xf/0xf arch/x86/entry/entry_64.S:607
 </IRQ>
RIP: 0010:preempt_count_add+0x0/0x160 kernel/sched/core.c:3773
Code: ff ff ff 44 89 e1 80 e1 07 80 c1 03 38 c1 0f 8c 3b ff ff ff 4c 89 e7 e8 7e 7a 5c 00 e9 2e ff ff ff 66 0f 1f 84 00 00 00 00 00 <55> 48 89 e5 41 57 41 56 53 89 fb 65 01 3d 6a 00 b2 7e 48 c7 c0 40
RSP: 0018:ffff888060e2fb40 EFLAGS: 00000246 ORIG_RAX: ffffffffffffffda
RAX: 0000000080000000 RBX: 000000000000020a RCX: 0000000000000001
RDX: 00000000000001a1 RSI: 0000000000000001 RDI: 0000000000000001
RBP: ffff888060e2fb68 R08: ffffffff8348439a R09: fffff5200211dbfb
R10: fffff5200211dbfb R11: 0000000000000000 R12: 000001a1201e4a96
R13: 0000000000000000 R14: 0000000000002ced R15: 0000000000000000
 __delay arch/x86/lib/delay.c:161 [inline]
 __const_udelay+0x5e/0x70 arch/x86/lib/delay.c:175
 try_check_zero+0x6e/0x380 kernel/rcu/srcutree.c:705
 srcu_advance_state kernel/rcu/srcutree.c:1142 [inline]
 process_srcu+0x1b7/0xd20 kernel/rcu/srcutree.c:1237
 process_one_work+0x7ef/0x10e0 kernel/workqueue.c:2269
 worker_thread+0xc01/0x1630 kernel/workqueue.c:2415
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352