sd 0:0:1:0: [sg0] tag#6795 CDB[50]: 00 00 40 00 00 00 00 00 00 00 40 00 00 00 00 00
sd 0:0:1:0: [sg0] tag#6795 CDB[60]: fc e2 10 00 00 00 00 00 fc e2 10 00 00 00 00 00
sd 0:0:1:0: [sg0] tag#6795 CDB[70]: 00 00 20 00 00 00 00
rcu: INFO: rcu_preempt self-detected stall on CPU
rcu: 	1-...!: (1 GPs behind) idle=932/1/0x4000000000000002 softirq=16972/16973 fqs=3 
	(t=10500 jiffies g=20425 q=324)
rcu: rcu_preempt kthread starved for 10492 jiffies! g20425 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     I29328    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3254 [inline]
 __schedule+0x755/0x15b0 kernel/sched/core.c:3921
 schedule+0xa8/0x270 kernel/sched/core.c:3985
 schedule_timeout+0x486/0xc50 kernel/time/timer.c:1893
 rcu_gp_fqs_loop kernel/rcu/tree.c:1611 [inline]
 rcu_gp_kthread+0x9b2/0x18c0 kernel/rcu/tree.c:1768
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352
NMI backtrace for cpu 1
CPU: 1 PID: 16 Comm: ksoftirqd/1 Not tainted 5.3.0-rc2-next-20190801 #57
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011
Call Trace:
 <IRQ>
 __dump_stack lib/dump_stack.c:77 [inline]
 dump_stack+0x172/0x1f0 lib/dump_stack.c:113
 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101
 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62
 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38
 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline]
 rcu_dump_cpu_stacks+0x183/0x1cf 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:2736 [inline]
 rcu_sched_clock_irq.cold+0x4dd/0xc13 kernel/rcu/tree.c:2183
 update_process_times+0x32/0x80 kernel/time/timer.c:1724
 tick_sched_handle+0xa2/0x190 kernel/time/tick-sched.c:167
 tick_sched_timer+0x53/0x140 kernel/time/tick-sched.c:1299
 __run_hrtimer kernel/time/hrtimer.c:1493 [inline]
 __hrtimer_run_queues+0x364/0xe40 kernel/time/hrtimer.c:1555
 hrtimer_interrupt+0x314/0x770 kernel/time/hrtimer.c:1617
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1068 [inline]
 smp_apic_timer_interrupt+0x160/0x610 arch/x86/kernel/apic/apic.c:1093
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828
 </IRQ>
RIP: 0010:cpu_relax arch/x86/include/asm/processor.h:656 [inline]
RIP: 0010:virt_spin_lock arch/x86/include/asm/qspinlock.h:84 [inline]
RIP: 0010:native_queued_spin_lock_slowpath+0x132/0x9f0 kernel/locking/qspinlock.c:325
Code: 00 00 00 48 8b 45 d0 65 48 33 04 25 28 00 00 00 0f 85 37 07 00 00 48 81 c4 98 00 00 00 5b 41 5c 41 5d 41 5e 41 5f 5d c3 f3 90 <e9> 73 ff ff ff 8b 45 98 4c 8d 65 d8 3d 00 01 00 00 0f 84 e5 00 00
RSP: 0018:ffff8880a990f9f8 EFLAGS: 00000202 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: ffff888063e0ed08 RCX: ffffffff8158f467
RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff888063e0ed08
RBP: ffff8880a990fab8 R08: 1ffff1100c7c1da1 R09: ffffed100c7c1da2
R10: ffffed100c7c1da1 R11: ffff888063e0ed0b R12: 0000000000000001
R13: 0000000000000003 R14: ffffed100c7c1da1 R15: 0000000000000001
 pv_queued_spin_lock_slowpath arch/x86/include/asm/paravirt.h:642 [inline]
 queued_spin_lock_slowpath arch/x86/include/asm/qspinlock.h:50 [inline]
 queued_spin_lock include/asm-generic/qspinlock.h:81 [inline]
 do_raw_spin_lock+0x20e/0x2e0 kernel/locking/spinlock_debug.c:113
 __raw_spin_lock include/linux/spinlock_api_smp.h:143 [inline]
 _raw_spin_lock+0x37/0x40 kernel/locking/spinlock.c:151
 spin_lock include/linux/spinlock.h:338 [inline]
 tcp_write_timer+0x2b/0x1e0 net/ipv4/tcp_timer.c:610
 call_timer_fn+0x1ac/0x780 kernel/time/timer.c:1404
 expire_timers kernel/time/timer.c:1449 [inline]
 __run_timers kernel/time/timer.c:1771 [inline]
 __run_timers kernel/time/timer.c:1738 [inline]
 run_timer_softirq+0x6c0/0x17f0 kernel/time/timer.c:1784
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 run_ksoftirqd kernel/softirq.c:603 [inline]
 run_ksoftirqd+0x8e/0x110 kernel/softirq.c:595
 smpboot_thread_fn+0x6a3/0xa40 kernel/smpboot.c:165
 kthread+0x361/0x430 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352