I saw this traceback on the 4.15.18 mainline build:

Sep 04 14:47:41 surprise kernel: ------------[ cut here ]------------
Sep 04 14:47:41 surprise kernel: NETDEV WATCHDOG: enp5s0 (r8169): transmit queue 0 timed out
Sep 04 14:47:41 surprise kernel: WARNING: CPU: 11 PID: 0 at /home/kernel/COD/linux/net/sched/sch_generic.c:323 dev_watchdog+0x221/0x230
Sep 04 14:47:41 surprise kernel: Modules linked in: devlink nft_meta nft_compat ipt_REJECT nf_reject_ipv4 xt_conntrack ipt_MASQUERADE nf_nat_masquerade_ipv4 xt_CHECKSUM xt_comment xt_tcpudp nft_chain_route_ipv6 iptable_mangle iptable_nat nft_chain_nat_ipv6 nf_conntrack_ipv6 nf_def>
Sep 04 14:47:41 surprise kernel:  videodev joydev input_leds media snd_seq snd_seq_device irqbypass snd_timer k10temp wmi_bmof snd ccp nvidia_uvm(OE) 8250 soundcore 8250_base shpchp mac_hid wmi iptable_filter ip6table_filter ip6_tables br_netfilter bridge stp llc arp_tables parpor>
Sep 04 14:47:41 surprise kernel: CPU: 11 PID: 0 Comm: swapper/11 Tainted: P           OE    4.15.18-041518-generic #201804190330
Sep 04 14:47:41 surprise kernel: Hardware name: Gigabyte Technology Co., Ltd. B450M DS3H/B450M DS3H-CF, BIOS F4 01/25/2019
Sep 04 14:47:41 surprise kernel: RIP: 0010:dev_watchdog+0x221/0x230
Sep 04 14:47:41 surprise kernel: RSP: 0018:ffff96204e8c3e58 EFLAGS: 00010286
Sep 04 14:47:41 surprise kernel: RAX: 0000000000000000 RBX: 0000000000000000 RCX: 0000000000000000
Sep 04 14:47:41 surprise kernel: RDX: 0000000000040400 RSI: 00000000000000f6 RDI: 0000000000000300
Sep 04 14:47:41 surprise kernel: RBP: ffff96204e8c3e88 R08: 0000000000000001 R09: 00000000000004c6
Sep 04 14:47:41 surprise kernel: R10: ffff96204e8c3ee0 R11: 0000000000000000 R12: 0000000000000001
Sep 04 14:47:41 surprise kernel: R13: ffff96204e32e000 R14: ffff96204e32e478 R15: ffff96203bd19880
Sep 04 14:47:41 surprise kernel: FS:  0000000000000000(0000) GS:ffff96204e8c0000(0000) knlGS:0000000000000000
Sep 04 14:47:41 surprise kernel: CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Sep 04 14:47:41 surprise kernel: CR2: 00007f564479a0c0 CR3: 000000040adb0000 CR4: 00000000003406e0
Sep 04 14:47:41 surprise kernel: Call Trace:
Sep 04 14:47:41 surprise kernel:  <IRQ>
Sep 04 14:47:41 surprise kernel:  ? dev_deactivate_queue.constprop.33+0x60/0x60
Sep 04 14:47:41 surprise kernel:  call_timer_fn+0x30/0x130
Sep 04 14:47:41 surprise kernel:  run_timer_softirq+0x3fb/0x450
Sep 04 14:47:41 surprise kernel:  ? ktime_get+0x43/0xa0
Sep 04 14:47:41 surprise kernel:  ? lapic_next_event+0x20/0x30
Sep 04 14:47:41 surprise kernel:  __do_softirq+0xdf/0x2b2
Sep 04 14:47:41 surprise kernel:  irq_exit+0xb6/0xc0
Sep 04 14:47:41 surprise kernel:  smp_apic_timer_interrupt+0x71/0x130
Sep 04 14:47:41 surprise kernel:  apic_timer_interrupt+0x84/0x90
Sep 04 14:47:41 surprise kernel:  </IRQ>
Sep 04 14:47:41 surprise kernel: RIP: 0010:cpuidle_enter_state+0xa7/0x2f0
Sep 04 14:47:41 surprise kernel: RSP: 0018:ffffabdc019fbe68 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff11
Sep 04 14:47:41 surprise kernel: RAX: ffff96204e8e2880 RBX: 00000013b8893c67 RCX: 000000000000001f
Sep 04 14:47:41 surprise kernel: RDX: 00000013b8893c67 RSI: fffffffc216ba992 RDI: 0000000000000000
Sep 04 14:47:41 surprise kernel: RBP: ffffabdc019fbea8 R08: 00000000000105ec R09: 0000000000000018
Sep 04 14:47:41 surprise kernel: R10: ffffabdc019fbe38 R11: 000000000000386e R12: ffff96203cae1800
Sep 04 14:47:41 surprise kernel: R13: 0000000000000002 R14: ffffffffb1f80098 R15: 0000000000000000
Sep 04 14:47:41 surprise kernel:  ? cpuidle_enter_state+0x97/0x2f0
Sep 04 14:47:41 surprise kernel:  cpuidle_enter+0x17/0x20
Sep 04 14:47:41 surprise kernel:  call_cpuidle+0x23/0x40
Sep 04 14:47:41 surprise kernel:  do_idle+0x18c/0x1f0
Sep 04 14:47:41 surprise kernel:  cpu_startup_entry+0x73/0x80
Sep 04 14:47:41 surprise kernel:  start_secondary+0x1a6/0x200
Sep 04 14:47:41 surprise kernel:  secondary_startup_64+0xa5/0xb0
Sep 04 14:47:41 surprise kernel: Code: 39 00 49 63 4e e8 eb 92 4c 89 ef c6 05 87 d7 d9 00 01 e8 83 39 fd ff 89 d9 48 89 c2 4c 89 ee 48 c7 c7 c8 68 b8 b1 e8 ff a4 81 ff <0f> 0b eb c0 90 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 44 00 00 55 
Sep 04 14:47:41 surprise kernel: ---[ end trace a02a9c8ad08e0a55 ]---