------------[ cut here ]------------
WARNING: CPU: 0 PID: 3876 at kernel/rcu/tree_stall.h:639 rcu_check_gp_start_stall kernel/rcu/tree_stall.h:639 [inline]
WARNING: CPU: 0 PID: 3876 at kernel/rcu/tree_stall.h:639 rcu_check_gp_start_stall.isra.0.cold+0xc/0x38 kernel/rcu/tree_stall.h:596
Kernel panic - not syncing: panic_on_warn set ...
CPU: 0 PID: 3876 Comm: udevd Not tainted 5.3.0-rc2-next-20190731 #56
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
 panic+0x2dc/0x755 kernel/panic.c:220
 __warn.cold+0x20/0x4c kernel/panic.c:584
 report_bug+0x263/0x2b0 lib/bug.c:186
 fixup_bug arch/x86/kernel/traps.c:179 [inline]
 fixup_bug arch/x86/kernel/traps.c:174 [inline]
 do_error_trap+0x11b/0x200 arch/x86/kernel/traps.c:272
 do_invalid_op+0x37/0x50 arch/x86/kernel/traps.c:291
 invalid_op+0x23/0x30 arch/x86/entry/entry_64.S:1026
RIP: 0010:rcu_check_gp_start_stall kernel/rcu/tree_stall.h:639 [inline]
RIP: 0010:rcu_check_gp_start_stall.isra.0.cold+0xc/0x38 kernel/rcu/tree_stall.h:596
Code: 4c 90 fb ff 0f 0b e9 89 0b ff ff 48 c7 c7 e0 2c 8d 87 e8 39 90 fb ff 0f 0b e9 61 0c ff ff 48 c7 c7 e0 2c 8d 87 e8 26 90 fb ff <0f> 0b 49 81 fc 00 db da 88 74 0c 48 c7 c7 00 db da 88 e8 7b 62 df
RSP: 0018:ffff8880ae809dc8 EFLAGS: 00010082
RAX: 0000000000000024 RBX: 000000010003b577 RCX: 0000000000000000
RDX: 0000000000000000 RSI: ffffffff815bbfd6 RDI: ffffed1015d013ab
RBP: ffff8880ae809de8 R08: 0000000000000024 R09: ffffed1015d060d1
R10: ffffed1015d060d0 R11: ffff8880ae830687 R12: ffffffff88dadb00
R13: 1ffffffff1181200 R14: 0000000000000286 R15: 0000000000000009
 rcu_core+0x431/0x1580 kernel/rcu/tree.c:2309
 rcu_core_si+0x9/0x10 kernel/rcu/tree.c:2323
 __do_softirq+0x262/0x98c kernel/softirq.c:292
 invoke_softirq kernel/softirq.c:373 [inline]
 irq_exit+0x19b/0x1e0 kernel/softirq.c:413
 exiting_irq arch/x86/include/asm/apic.h:536 [inline]
 smp_apic_timer_interrupt+0x1a3/0x610 arch/x86/kernel/apic/apic.c:1095
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:828
 </IRQ>
RIP: 0010:__raw_write_unlock_irq include/linux/rwlock_api_smp.h:268 [inline]
RIP: 0010:_raw_write_unlock_irq+0x54/0x90 kernel/locking/spinlock.c:343
Code: c0 b0 f4 d2 88 48 ba 00 00 00 00 00 fc ff df 48 c1 e8 03 80 3c 10 00 75 33 48 83 3d 25 70 93 01 00 74 20 fb 66 0f 1f 44 00 00 <bf> 01 00 00 00 e8 c2 87 0e fa 65 8b 05 63 79 c2 78 85 c0 74 06 41
RSP: 0018:ffff888096bdfbf0 EFLAGS: 00000282 ORIG_RAX: ffffffffffffff13
RAX: 1ffffffff11a5e96 RBX: ffff888096362b00 RCX: 1ffffffff134c016
RDX: dffffc0000000000 RSI: ffffffff8177a12e RDI: ffffffff873f8468
RBP: ffff888096bdfbf8 R08: ffff888096bd0340 R09: fffffbfff134b9d9
R10: fffffbfff134b9d8 R11: ffffffff89a5cec7 R12: ffff888096362b20
R13: ffff888096bdfdc0 R14: ffff888096362b10 R15: ffff888096362b20
 ep_scan_ready_list+0x779/0xb20 fs/eventpoll.c:752
 ep_send_events fs/eventpoll.c:1793 [inline]
 ep_poll+0x1f9/0xe60 fs/eventpoll.c:1930
 do_epoll_wait+0x210/0x260 fs/eventpoll.c:2294
 __do_sys_epoll_wait fs/eventpoll.c:2304 [inline]
 __se_sys_epoll_wait fs/eventpoll.c:2301 [inline]
 __x64_sys_epoll_wait+0x97/0xf0 fs/eventpoll.c:2301
 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f5e9a72e943
Code: 00 31 d2 48 29 c2 64 89 11 48 83 c8 ff eb ea 90 90 90 90 90 90 90 90 83 3d b5 dc 2a 00 00 75 13 49 89 ca b8 e8 00 00 00 0f 05 <48> 3d 01 f0 ff ff 73 34 c3 48 83 ec 08 e8 3b c4 00 00 48 89 04 24
RSP: 002b:00007ffcda5d8068 EFLAGS: 00000246 ORIG_RAX: 00000000000000e8
RAX: ffffffffffffffda RBX: 0000000000000bb8 RCX: 00007f5e9a72e943
RDX: 0000000000000008 RSI: 00007ffcda5d8160 RDI: 000000000000000a
RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001
R10: 0000000000000bb8 R11: 0000000000000246 R12: 0000000000000003
R13: 0000000000000000 R14: 000000000154eb10 R15: 000000000154c250
Kernel Offset: disabled
Rebooting in 86400 seconds..