I'd like to add that I'm seeing this with Groovy as well:
Oct 26 19:08:40 ubuntu kernel: ------------[ cut here ]------------
Oct 26 19:08:40 ubuntu kernel: NETDEV WATCHDOG: enp3s0 (r8169): transmit queue 0 timed out
Oct 26 19:08:40 ubuntu kernel: WARNING: CPU: 6 PID: 0 at net/sched/sch_generic.c:442 dev_watchdog+0x25b/0x270
Oct 26 19:08:40 ubuntu kernel: Modules linked in: cfg80211 8021q garp mrp stp llc nls_iso8859_1 snd_hda_codec_realtek snd_hda_codec_generic intel_rapl_msr mei_hdcp ledtrig_audio snd_hda_codec_hdmi snd_hda_intel in>
Oct 26 19:08:40 ubuntu kernel: hid_generic usbhid hid uas usb_storage amdgpu iommu_v2 gpu_sched i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_inte>
Oct 26 19:08:40 ubuntu kernel: CPU: 6 PID: 0 Comm: swapper/6 Tainted: G OE 5.8.0-7625-generic #26~1603126178~20.10~210fe73-Ubuntu
Oct 26 19:08:40 ubuntu kernel: Hardware name: MSI MS-7850/H97 PC Mate(MS-7850), BIOS V5.9 02/16/2016
Oct 26 19:08:40 ubuntu kernel: RIP: 0010:dev_watchdog+0x25b/0x270
Oct 26 19:08:40 ubuntu kernel: Code: 85 c0 75 e5 eb 9c 4c 89 ff c6 05 26 85 1c 01 01 e8 2a 93 fa ff 44 89 e9 4c 89 fe 48 c7 c7 c0 7a a8 b1 48 89 c2 e8 ba 30 64 ff <0f> 0b e9 7a ff ff ff 66 66 2e 0f 1f 84 00 00 00 >
Oct 26 19:08:40 ubuntu kernel: RSP: 0018:ffffad1500210e78 EFLAGS: 00010286
Oct 26 19:08:40 ubuntu kernel: RAX: 0000000000000000 RBX: ffff9b0179912200 RCX: ffff9b018dd98cd8
Oct 26 19:08:40 ubuntu kernel: RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9b018dd98cd0
Oct 26 19:08:40 ubuntu kernel: RBP: ffffad1500210ea8 R08: 0000000000000004 R09: 000000000000047a
Oct 26 19:08:40 ubuntu kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff9b0179912280
Oct 26 19:08:40 ubuntu kernel: R13: 0000000000000000 R14: ffff9b01788da480 R15: ffff9b01788da000
Oct 26 19:08:40 ubuntu kernel: FS: 0000000000000000(0000) GS:ffff9b018dd80000(0000) knlGS:0000000000000000
Oct 26 19:08:40 ubuntu kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 26 19:08:40 ubuntu kernel: CR2: 00007f7677e18c90 CR3: 00000000a5c0a005 CR4: 00000000001606e0
Oct 26 19:08:40 ubuntu kernel: Call Trace:
Oct 26 19:08:40 ubuntu kernel: <IRQ>
Oct 26 19:08:40 ubuntu kernel: ? pfifo_fast_enqueue+0x150/0x150
Oct 26 19:08:40 ubuntu kernel: call_timer_fn+0x32/0x130
Oct 26 19:08:40 ubuntu kernel: __run_timers.part.0+0x184/0x280
Oct 26 19:08:40 ubuntu kernel: ? lapic_next_deadline+0x26/0x30
Oct 26 19:08:40 ubuntu kernel: ? clockevents_program_event+0x8f/0xe0
Oct 26 19:08:40 ubuntu kernel: run_timer_softirq+0x2a/0x50
Oct 26 19:08:40 ubuntu kernel: __do_softirq+0xd0/0x2a1
Oct 26 19:08:40 ubuntu kernel: asm_call_irq_on_stack+0x12/0x20
Oct 26 19:08:40 ubuntu kernel: </IRQ>
Oct 26 19:08:40 ubuntu kernel: do_softirq_own_stack+0x3d/0x50
Oct 26 19:08:40 ubuntu kernel: irq_exit_rcu+0x95/0xd0
Oct 26 19:08:40 ubuntu kernel: sysvec_apic_timer_interrupt+0x3b/0x90
Oct 26 19:08:40 ubuntu kernel: asm_sysvec_apic_timer_interrupt+0x12/0x20
Oct 26 19:08:40 ubuntu kernel: RIP: 0010:cpuidle_enter_state+0xb7/0x3f0
Oct 26 19:08:40 ubuntu kernel: Code: 3f fb 06 4f e8 4a 5d 74 ff 48 89 45 d0 0f 1f 44 00 00 31 ff e8 fa 68 74 ff 80 7d c7 00 0f 85 d3 01 00 00 fb 66 0f 1f 44 00 00 <45> 85 e4 0f 88 df 01 00 00 49 63 d4 48 8d 04 52 >
Oct 26 19:08:40 ubuntu kernel: RSP: 0018:ffffad15000c7e48 EFLAGS: 00000246
Oct 26 19:08:40 ubuntu kernel: RAX: ffff9b018ddac6c0 RBX: ffff9b018ddb7900 RCX: 000000000000001f
Oct 26 19:08:40 ubuntu kernel: RDX: 0000000000000000 RSI: 000000002000029f RDI: 0000000000000000
Oct 26 19:08:40 ubuntu kernel: RBP: ffffad15000c7e88 R08: 0000000aae6ba9e9 R09: 00000000ffffffff
Oct 26 19:08:40 ubuntu kernel: R10: 000000000000011b R11: ffff9b018ddab364 R12: 0000000000000005
Oct 26 19:08:40 ubuntu kernel: R13: ffffffffb216adc0 R14: 0000000000000005 R15: 0000000000000000
Oct 26 19:08:40 ubuntu kernel: ? cpuidle_enter_state+0xa6/0x3f0
Oct 26 19:08:40 ubuntu kernel: cpuidle_enter+0x2e/0x40
Oct 26 19:08:40 ubuntu kernel: cpuidle_idle_call+0x145/0x200
Oct 26 19:08:40 ubuntu kernel: do_idle+0x7a/0xe0
Oct 26 19:08:40 ubuntu kernel: cpu_startup_entry+0x20/0x30
Oct 26 19:08:40 ubuntu kernel: start_secondary+0xe6/0x100
Oct 26 19:08:40 ubuntu kernel: secondary_startup_64+0xb6/0xc0
Oct 26 19:08:40 ubuntu kernel: ---[ end trace ef40ba07e8939a6f ]---
Oct 26 19:08:40 ubuntu kernel: r8169 0000:03:00.0 enp3s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
I'm currently running 5.4.0-7642.46~1598628707~20.04~040157c (Pop_OS!) to mitigate this issue, but it's currently present in 5.8.0-7625.26~1603126178~20.10~210fe73.
I'd like to add that I'm seeing this with Groovy as well:
Oct 26 19:08:40 ubuntu kernel: ------------[ cut here ]------------ sch_generic. c:442 dev_watchdog+ 0x25b/0x270 codec_realtek snd_hda_ codec_generic intel_rapl_msr mei_hdcp ledtrig_audio snd_hda_codec_hdmi snd_hda_intel in> 20.10~210fe73- Ubuntu watchdog+ 0x25b/0x270 210e78 EFLAGS: 00010286 0(0000) GS:ffff9b018dd8 0000(0000) knlGS:000000000 0000000 enqueue+ 0x150/0x150 fn+0x32/ 0x130 part.0+ 0x184/0x280 deadline+ 0x26/0x30 program_ event+0x8f/ 0xe0 softirq+ 0x2a/0x50 0xd0/0x2a1 irq_on_ stack+0x12/ 0x20 own_stack+ 0x3d/0x50 rcu+0x95/ 0xd0 apic_timer_ interrupt+ 0x3b/0x90 apic_timer_ interrupt+ 0x12/0x20 enter_state+ 0xb7/0x3f0 0c7e48 EFLAGS: 00000246 enter_state+ 0xa6/0x3f0 enter+0x2e/ 0x40 idle_call+ 0x145/0x200 entry+0x20/ 0x30 +0xe6/0x100 startup_ 64+0xb6/ 0xc0
Oct 26 19:08:40 ubuntu kernel: NETDEV WATCHDOG: enp3s0 (r8169): transmit queue 0 timed out
Oct 26 19:08:40 ubuntu kernel: WARNING: CPU: 6 PID: 0 at net/sched/
Oct 26 19:08:40 ubuntu kernel: Modules linked in: cfg80211 8021q garp mrp stp llc nls_iso8859_1 snd_hda_
Oct 26 19:08:40 ubuntu kernel: hid_generic usbhid hid uas usb_storage amdgpu iommu_v2 gpu_sched i2c_algo_bit ttm drm_kms_helper syscopyarea sysfillrect crct10dif_pclmul crc32_pclmul ghash_clmulni_intel aesni_inte>
Oct 26 19:08:40 ubuntu kernel: CPU: 6 PID: 0 Comm: swapper/6 Tainted: G OE 5.8.0-7625-generic #26~1603126178~
Oct 26 19:08:40 ubuntu kernel: Hardware name: MSI MS-7850/H97 PC Mate(MS-7850), BIOS V5.9 02/16/2016
Oct 26 19:08:40 ubuntu kernel: RIP: 0010:dev_
Oct 26 19:08:40 ubuntu kernel: Code: 85 c0 75 e5 eb 9c 4c 89 ff c6 05 26 85 1c 01 01 e8 2a 93 fa ff 44 89 e9 4c 89 fe 48 c7 c7 c0 7a a8 b1 48 89 c2 e8 ba 30 64 ff <0f> 0b e9 7a ff ff ff 66 66 2e 0f 1f 84 00 00 00 >
Oct 26 19:08:40 ubuntu kernel: RSP: 0018:ffffad1500
Oct 26 19:08:40 ubuntu kernel: RAX: 0000000000000000 RBX: ffff9b0179912200 RCX: ffff9b018dd98cd8
Oct 26 19:08:40 ubuntu kernel: RDX: 00000000ffffffd8 RSI: 0000000000000027 RDI: ffff9b018dd98cd0
Oct 26 19:08:40 ubuntu kernel: RBP: ffffad1500210ea8 R08: 0000000000000004 R09: 000000000000047a
Oct 26 19:08:40 ubuntu kernel: R10: 0000000000000000 R11: 0000000000000001 R12: ffff9b0179912280
Oct 26 19:08:40 ubuntu kernel: R13: 0000000000000000 R14: ffff9b01788da480 R15: ffff9b01788da000
Oct 26 19:08:40 ubuntu kernel: FS: 000000000000000
Oct 26 19:08:40 ubuntu kernel: CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Oct 26 19:08:40 ubuntu kernel: CR2: 00007f7677e18c90 CR3: 00000000a5c0a005 CR4: 00000000001606e0
Oct 26 19:08:40 ubuntu kernel: Call Trace:
Oct 26 19:08:40 ubuntu kernel: <IRQ>
Oct 26 19:08:40 ubuntu kernel: ? pfifo_fast_
Oct 26 19:08:40 ubuntu kernel: call_timer_
Oct 26 19:08:40 ubuntu kernel: __run_timers.
Oct 26 19:08:40 ubuntu kernel: ? lapic_next_
Oct 26 19:08:40 ubuntu kernel: ? clockevents_
Oct 26 19:08:40 ubuntu kernel: run_timer_
Oct 26 19:08:40 ubuntu kernel: __do_softirq+
Oct 26 19:08:40 ubuntu kernel: asm_call_
Oct 26 19:08:40 ubuntu kernel: </IRQ>
Oct 26 19:08:40 ubuntu kernel: do_softirq_
Oct 26 19:08:40 ubuntu kernel: irq_exit_
Oct 26 19:08:40 ubuntu kernel: sysvec_
Oct 26 19:08:40 ubuntu kernel: asm_sysvec_
Oct 26 19:08:40 ubuntu kernel: RIP: 0010:cpuidle_
Oct 26 19:08:40 ubuntu kernel: Code: 3f fb 06 4f e8 4a 5d 74 ff 48 89 45 d0 0f 1f 44 00 00 31 ff e8 fa 68 74 ff 80 7d c7 00 0f 85 d3 01 00 00 fb 66 0f 1f 44 00 00 <45> 85 e4 0f 88 df 01 00 00 49 63 d4 48 8d 04 52 >
Oct 26 19:08:40 ubuntu kernel: RSP: 0018:ffffad1500
Oct 26 19:08:40 ubuntu kernel: RAX: ffff9b018ddac6c0 RBX: ffff9b018ddb7900 RCX: 000000000000001f
Oct 26 19:08:40 ubuntu kernel: RDX: 0000000000000000 RSI: 000000002000029f RDI: 0000000000000000
Oct 26 19:08:40 ubuntu kernel: RBP: ffffad15000c7e88 R08: 0000000aae6ba9e9 R09: 00000000ffffffff
Oct 26 19:08:40 ubuntu kernel: R10: 000000000000011b R11: ffff9b018ddab364 R12: 0000000000000005
Oct 26 19:08:40 ubuntu kernel: R13: ffffffffb216adc0 R14: 0000000000000005 R15: 0000000000000000
Oct 26 19:08:40 ubuntu kernel: ? cpuidle_
Oct 26 19:08:40 ubuntu kernel: cpuidle_
Oct 26 19:08:40 ubuntu kernel: cpuidle_
Oct 26 19:08:40 ubuntu kernel: do_idle+0x7a/0xe0
Oct 26 19:08:40 ubuntu kernel: cpu_startup_
Oct 26 19:08:40 ubuntu kernel: start_secondary
Oct 26 19:08:40 ubuntu kernel: secondary_
Oct 26 19:08:40 ubuntu kernel: ---[ end trace ef40ba07e8939a6f ]---
Oct 26 19:08:40 ubuntu kernel: r8169 0000:03:00.0 enp3s0: rtl_rxtx_empty_cond == 0 (loop: 42, delay: 100).
I'm currently running 5.4.0-7642. 46~1598628707~ 20.04~040157c (Pop_OS!) to mitigate this issue, but it's currently present in 5.8.0-7625. 26~1603126178~ 20.10~210fe73.
Same symptoms as the original reporter.