I'm still seeing this problem in stock amd64 16.04 (kernel 4.4.0-21):
Apr 28 13:46:37 rincewind kernel: [ 108.345612] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [QQmlThread:1159] Apr 28 13:46:37 rincewind kernel: [ 108.347049] Modules linked in: pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) ftdi_sio pl2303 usbserial snd_usb_audio snd_usbmidi_lib snd_hda_codec_hdmi nvidia_uvm(POE) coretemp kvm_intel snd_hda_codec_realtek snd_hda_codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep kvm snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer snd gpio_ich dcdbas dell_smm_hwmon input_leds shpchp soundcore serio_raw mei_me mei irqbypass i7core_edac 8250_fintek edac_core lpc_ich mac_hid parport_pc ppdev lp parport autofs4 hid_generic usbhid hid broadcom bcm_phy_lib nvidia_drm(POE) nvidia_modeset(POE) nvidia(POE) drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops tg3 drm ahci ptp libahci pps_core fjes Apr 28 13:46:37 rincewind kernel: [ 108.347082] CPU: 0 PID: 1159 Comm: QQmlThread Tainted: P OE 4.4.0-21-generic #37-Ubuntu Apr 28 13:46:37 rincewind kernel: [ 108.347084] Hardware name: Dell Inc. Vostro 430/054KM3, BIOS 2.2.0 07/06/2010 Apr 28 13:46:37 rincewind kernel: [ 108.347085] task: ffff8804264b8000 ti: ffff880429d98000 task.ti: ffff880429d98000 Apr 28 13:46:37 rincewind kernel: [ 108.347086] RIP: 0010:[<ffffffff81823f35>] [<ffffffff81823f35>] _raw_spin_unlock_irqrestore+0x15/0x20 Apr 28 13:46:37 rincewind kernel: [ 108.347092] RSP: 0018:ffff880429d9b910 EFLAGS: 00000282 Apr 28 13:46:37 rincewind kernel: [ 108.347093] RAX: 0000000000000009 RBX: 0000000000000000 RCX: 0000000000000051 Apr 28 13:46:37 rincewind kernel: [ 108.347094] RDX: ffffffffc0621d16 RSI: 0000000000000282 RDI: 0000000000000282 Apr 28 13:46:37 rincewind kernel: [ 108.347095] RBP: ffff880429d9b910 R08: 0000000000000000 R09: 0000000000000020 Apr 28 13:46:37 rincewind kernel: [ 108.347096] R10: ffff880427f9df18 R11: ffffffffc0651de0 R12: ffffffffc0a5a638 Apr 28 13:46:37 rincewind kernel: [ 108.347097] R13: 00000000ffffffff R14: 0000000000000001 R15: 0000000000000001 Apr 28 13:46:37 rincewind kernel: [ 108.347099] FS: 00007f10badef700(0000) GS:ffff88043fc00000(0000) knlGS:0000000000000000 Apr 28 13:46:37 rincewind kernel: [ 108.347100] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 Apr 28 13:46:37 rincewind kernel: [ 108.347101] CR2: 0000000001154a70 CR3: 0000000001e0a000 CR4: 00000000000006f0 Apr 28 13:46:37 rincewind kernel: [ 108.347102] Stack: Apr 28 13:46:37 rincewind kernel: [ 108.347103] ffff880429d9b920 ffffffffc015ee4a ffff880427f9df40 ffffffffc063b959 Apr 28 13:46:37 rincewind kernel: [ 108.347104] ffff8800b9034008 ffff880429064008 0000000000000000 ffff88042ac1c2a0 Apr 28 13:46:37 rincewind kernel: [ 108.347106] 00000000c1d00060 ffffffffc0621d16 ffffffffc09b8b08 00000000c1d00060 Apr 28 13:46:37 rincewind kernel: [ 108.347108] Call Trace: Apr 28 13:46:37 rincewind kernel: [ 108.347209] [<ffffffffc015ee4a>] os_release_spinlock+0x1a/0x20 [nvidia] Apr 28 13:46:37 rincewind kernel: [ 108.347295] [<ffffffffc063b959>] _nv016600rm+0x5f9/0x6e0 [nvidia] Apr 28 13:46:37 rincewind kernel: [ 108.347383] [<ffffffffc0621d16>] ? _nv000746rm+0x596/0x2940 [nvidia] Apr 28 13:46:37 rincewind kernel: [ 108.347470] [<ffffffffc0621629>] ? _nv000710rm+0x1b09/0x1bc0 [nvidia] Apr 28 13:46:37 rincewind kernel: [ 108.347558] [<ffffffffc0621732>] ? _nv016605rm+0x52/0x80 [nvidia] Apr 28 13:46:37 rincewind kernel: [ 108.347650] [<ffffffffc05f6d35>] ? _nv000141rm+0x55/0x70 [nvidia] Apr 28 13:46:37 rincewind kernel: [ 108.347727] [<ffffffffc068d853>] ? _nv000734rm+0x103/0x340 [nvidia] Apr 28 13:46:37 rincewind kernel: [ 108.347805] [<ffffffffc0681bda>] ? rm_disable_adapter+0x6a/0x130 [nvidia] Apr 28 13:46:37 rincewind kernel: [ 108.347810] [<ffffffff810c9d00>] ? down_trylock+0x10/0x40 Apr 28 13:46:37 rincewind kernel: [ 108.347866] [<ffffffffc0161f73>] ? nv_uvm_notify_stop_device+0x63/0x80 [nvidia] Apr 28 13:46:37 rincewind kernel: [ 108.347920] [<ffffffffc015377d>] ? nv_close_device+0xed/0x130 [nvidia] Apr 28 13:46:37 rincewind kernel: [ 108.347974] [<ffffffffc0157157>] ? nvidia_dev_put+0x27/0x40 [nvidia] Apr 28 13:46:37 rincewind kernel: [ 108.347991] [<ffffffffc0bc6b17>] ? nvkms_close_gpu+0x57/0x70 [nvidia_modeset] Apr 28 13:46:37 rincewind kernel: [ 108.348002] [<ffffffffc0bfdaa5>] ? _nv001953kms+0xf5/0x180 [nvidia_modeset] Apr 28 13:46:37 rincewind kernel: [ 108.348010] [<ffffffffc0bdae7d>] ? _nv001859kms+0x3d/0x80 [nvidia_modeset] Apr 28 13:46:37 rincewind kernel: [ 108.348017] [<ffffffffc0bc8253>] ? _nv000189kms+0x53/0x130 [nvidia_modeset] Apr 28 13:46:37 rincewind kernel: [ 108.348025] [<ffffffffc0bc83ac>] ? nvKmsClose+0x7c/0x120 [nvidia_modeset] Apr 28 13:46:37 rincewind kernel: [ 108.348032] [<ffffffffc0bc6cd1>] ? nvkms_close_common+0x21/0x60 [nvidia_modeset] Apr 28 13:46:37 rincewind kernel: [ 108.348040] [<ffffffffc0bc6d2a>] ? nvkms_close+0x1a/0x30 [nvidia_modeset] Apr 28 13:46:37 rincewind kernel: [ 108.348093] [<ffffffffc015339c>] ? nvidia_frontend_close+0x2c/0x50 [nvidia] Apr 28 13:46:37 rincewind kernel: [ 108.348096] [<ffffffff8120e514>] ? __fput+0xe4/0x220 Apr 28 13:46:37 rincewind kernel: [ 108.348098] [<ffffffff8120e68e>] ? ____fput+0xe/0x10 Apr 28 13:46:37 rincewind kernel: [ 108.348101] [<ffffffff8109e943>] ? task_work_run+0x73/0x90 Apr 28 13:46:37 rincewind kernel: [ 108.348104] [<ffffffff81083ba4>] ? do_exit+0x2e4/0xae0 Apr 28 13:46:37 rincewind kernel: [ 108.348106] [<ffffffff81084423>] ? do_group_exit+0x43/0xb0 Apr 28 13:46:37 rincewind kernel: [ 108.348108] [<ffffffff810904d2>] ? get_signal+0x292/0x600 Apr 28 13:46:37 rincewind kernel: [ 108.348111] [<ffffffff8102e517>] ? do_signal+0x37/0x6f0 Apr 28 13:46:37 rincewind kernel: [ 108.348114] [<ffffffff81102e3e>] ? do_futex+0x34e/0x500 Apr 28 13:46:37 rincewind kernel: [ 108.348117] [<ffffffff811c8df4>] ? mprotect_fixup+0x154/0x240 Apr 28 13:46:37 rincewind kernel: [ 108.348120] [<ffffffff8100320c>] ? exit_to_usermode_loop+0x8c/0xd0 Apr 28 13:46:37 rincewind kernel: [ 108.348122] [<ffffffff81003c5e>] ? syscall_return_slowpath+0x4e/0x60 Apr 28 13:46:37 rincewind kernel: [ 108.348124] [<ffffffff81824650>] ? int_ret_from_sys_call+0x25/0x8f Apr 28 13:46:37 rincewind kernel: [ 108.348125] Code: 90 66 66 90 eb c6 31 c0 eb ca e8 27 ce 85 ff 90 90 90 90 90 90 90 66 66 66 66 90 55 48 89 e5 c6 07 00 66 66 66 90 48 89 f7 57 9d <66> 66 90 66 90 5d c3 0f 1f 40 00 66 66 66 66 90 55 48 89 e5 c6
Am now running 4.5.2 to see if the problem persists.
I'm still seeing this problem in stock amd64 16.04 (kernel 4.4.0-21):
Apr 28 13:46:37 rincewind kernel: [ 108.345612] NMI watchdog: BUG: soft lockup - CPU#0 stuck for 22s! [QQmlThread:1159] codec_realtek snd_hda_ codec_generic snd_hda_intel snd_hda_codec snd_hda_core snd_hwdep kvm snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device snd_timer snd gpio_ich dcdbas dell_smm_hwmon input_leds shpchp soundcore serio_raw mei_me mei irqbypass i7core_edac 8250_fintek edac_core lpc_ich mac_hid parport_pc ppdev lp parport autofs4 hid_generic usbhid hid broadcom bcm_phy_lib nvidia_drm(POE) nvidia_modeset(POE) nvidia(POE) drm_kms_helper syscopyarea sysfillrect sysimgblt fb_sys_fops tg3 drm ahci ptp libahci pps_core fjes ffffffff81823f3 5>] [<ffffffff81823 f35>] _raw_spin_ unlock_ irqrestore+ 0x15/0x20 d9b910 EFLAGS: 00000282 0(0000) GS:ffff88043fc0 0000(0000) knlGS:000000000 0000000 e4a>] os_release_ spinlock+ 0x1a/0x20 [nvidia] 959>] _nv016600rm+ 0x5f9/0x6e0 [nvidia] d16>] ? _nv000746rm+ 0x596/0x2940 [nvidia] 629>] ? _nv000710rm+ 0x1b09/ 0x1bc0 [nvidia] 732>] ? _nv016605rm+ 0x52/0x80 [nvidia] d35>] ? _nv000141rm+ 0x55/0x70 [nvidia] 853>] ? _nv000734rm+ 0x103/0x340 [nvidia] bda>] ? rm_disable_ adapter+ 0x6a/0x130 [nvidia] d00>] ? down_trylock+ 0x10/0x40 f73>] ? nv_uvm_ notify_ stop_device+ 0x63/0x80 [nvidia] 77d>] ? nv_close_ device+ 0xed/0x130 [nvidia] 157>] ? nvidia_ dev_put+ 0x27/0x40 [nvidia] b17>] ? nvkms_close_ gpu+0x57/ 0x70 [nvidia_modeset] aa5>] ? _nv001953kms+ 0xf5/0x180 [nvidia_modeset] e7d>] ? _nv001859kms+ 0x3d/0x80 [nvidia_modeset] 253>] ? _nv000189kms+ 0x53/0x130 [nvidia_modeset] 3ac>] ? nvKmsClose+ 0x7c/0x120 [nvidia_modeset] cd1>] ? nvkms_close_ common+ 0x21/0x60 [nvidia_modeset] d2a>] ? nvkms_close+ 0x1a/0x30 [nvidia_modeset] 39c>] ? nvidia_ frontend_ close+0x2c/ 0x50 [nvidia] 514>] ? __fput+0xe4/0x220 68e>] ? ____fput+0xe/0x10 943>] ? task_work_ run+0x73/ 0x90 ba4>] ? do_exit+0x2e4/0xae0 423>] ? do_group_ exit+0x43/ 0xb0 4d2>] ? get_signal+ 0x292/0x600 517>] ? do_signal+ 0x37/0x6f0 e3e>] ? do_futex+ 0x34e/0x500 df4>] ? mprotect_ fixup+0x154/ 0x240 20c>] ? exit_to_ usermode_ loop+0x8c/ 0xd0 c5e>] ? syscall_ return_ slowpath+ 0x4e/0x60 650>] ? int_ret_ from_sys_ call+0x25/ 0x8f
Apr 28 13:46:37 rincewind kernel: [ 108.347049] Modules linked in: pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) vboxdrv(OE) ftdi_sio pl2303 usbserial snd_usb_audio snd_usbmidi_lib snd_hda_codec_hdmi nvidia_uvm(POE) coretemp kvm_intel snd_hda_
Apr 28 13:46:37 rincewind kernel: [ 108.347082] CPU: 0 PID: 1159 Comm: QQmlThread Tainted: P OE 4.4.0-21-generic #37-Ubuntu
Apr 28 13:46:37 rincewind kernel: [ 108.347084] Hardware name: Dell Inc. Vostro 430/054KM3, BIOS 2.2.0 07/06/2010
Apr 28 13:46:37 rincewind kernel: [ 108.347085] task: ffff8804264b8000 ti: ffff880429d98000 task.ti: ffff880429d98000
Apr 28 13:46:37 rincewind kernel: [ 108.347086] RIP: 0010:[<
Apr 28 13:46:37 rincewind kernel: [ 108.347092] RSP: 0018:ffff880429
Apr 28 13:46:37 rincewind kernel: [ 108.347093] RAX: 0000000000000009 RBX: 0000000000000000 RCX: 0000000000000051
Apr 28 13:46:37 rincewind kernel: [ 108.347094] RDX: ffffffffc0621d16 RSI: 0000000000000282 RDI: 0000000000000282
Apr 28 13:46:37 rincewind kernel: [ 108.347095] RBP: ffff880429d9b910 R08: 0000000000000000 R09: 0000000000000020
Apr 28 13:46:37 rincewind kernel: [ 108.347096] R10: ffff880427f9df18 R11: ffffffffc0651de0 R12: ffffffffc0a5a638
Apr 28 13:46:37 rincewind kernel: [ 108.347097] R13: 00000000ffffffff R14: 0000000000000001 R15: 0000000000000001
Apr 28 13:46:37 rincewind kernel: [ 108.347099] FS: 00007f10badef70
Apr 28 13:46:37 rincewind kernel: [ 108.347100] CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033
Apr 28 13:46:37 rincewind kernel: [ 108.347101] CR2: 0000000001154a70 CR3: 0000000001e0a000 CR4: 00000000000006f0
Apr 28 13:46:37 rincewind kernel: [ 108.347102] Stack:
Apr 28 13:46:37 rincewind kernel: [ 108.347103] ffff880429d9b920 ffffffffc015ee4a ffff880427f9df40 ffffffffc063b959
Apr 28 13:46:37 rincewind kernel: [ 108.347104] ffff8800b9034008 ffff880429064008 0000000000000000 ffff88042ac1c2a0
Apr 28 13:46:37 rincewind kernel: [ 108.347106] 00000000c1d00060 ffffffffc0621d16 ffffffffc09b8b08 00000000c1d00060
Apr 28 13:46:37 rincewind kernel: [ 108.347108] Call Trace:
Apr 28 13:46:37 rincewind kernel: [ 108.347209] [<ffffffffc015e
Apr 28 13:46:37 rincewind kernel: [ 108.347295] [<ffffffffc063b
Apr 28 13:46:37 rincewind kernel: [ 108.347383] [<ffffffffc0621
Apr 28 13:46:37 rincewind kernel: [ 108.347470] [<ffffffffc0621
Apr 28 13:46:37 rincewind kernel: [ 108.347558] [<ffffffffc0621
Apr 28 13:46:37 rincewind kernel: [ 108.347650] [<ffffffffc05f6
Apr 28 13:46:37 rincewind kernel: [ 108.347727] [<ffffffffc068d
Apr 28 13:46:37 rincewind kernel: [ 108.347805] [<ffffffffc0681
Apr 28 13:46:37 rincewind kernel: [ 108.347810] [<ffffffff810c9
Apr 28 13:46:37 rincewind kernel: [ 108.347866] [<ffffffffc0161
Apr 28 13:46:37 rincewind kernel: [ 108.347920] [<ffffffffc0153
Apr 28 13:46:37 rincewind kernel: [ 108.347974] [<ffffffffc0157
Apr 28 13:46:37 rincewind kernel: [ 108.347991] [<ffffffffc0bc6
Apr 28 13:46:37 rincewind kernel: [ 108.348002] [<ffffffffc0bfd
Apr 28 13:46:37 rincewind kernel: [ 108.348010] [<ffffffffc0bda
Apr 28 13:46:37 rincewind kernel: [ 108.348017] [<ffffffffc0bc8
Apr 28 13:46:37 rincewind kernel: [ 108.348025] [<ffffffffc0bc8
Apr 28 13:46:37 rincewind kernel: [ 108.348032] [<ffffffffc0bc6
Apr 28 13:46:37 rincewind kernel: [ 108.348040] [<ffffffffc0bc6
Apr 28 13:46:37 rincewind kernel: [ 108.348093] [<ffffffffc0153
Apr 28 13:46:37 rincewind kernel: [ 108.348096] [<ffffffff8120e
Apr 28 13:46:37 rincewind kernel: [ 108.348098] [<ffffffff8120e
Apr 28 13:46:37 rincewind kernel: [ 108.348101] [<ffffffff8109e
Apr 28 13:46:37 rincewind kernel: [ 108.348104] [<ffffffff81083
Apr 28 13:46:37 rincewind kernel: [ 108.348106] [<ffffffff81084
Apr 28 13:46:37 rincewind kernel: [ 108.348108] [<ffffffff81090
Apr 28 13:46:37 rincewind kernel: [ 108.348111] [<ffffffff8102e
Apr 28 13:46:37 rincewind kernel: [ 108.348114] [<ffffffff81102
Apr 28 13:46:37 rincewind kernel: [ 108.348117] [<ffffffff811c8
Apr 28 13:46:37 rincewind kernel: [ 108.348120] [<ffffffff81003
Apr 28 13:46:37 rincewind kernel: [ 108.348122] [<ffffffff81003
Apr 28 13:46:37 rincewind kernel: [ 108.348124] [<ffffffff81824
Apr 28 13:46:37 rincewind kernel: [ 108.348125] Code: 90 66 66 90 eb c6 31 c0 eb ca e8 27 ce 85 ff 90 90 90 90 90 90 90 66 66 66 66 90 55 48 89 e5 c6 07 00 66 66 66 90 48 89 f7 57 9d <66> 66 90 66 90 5d c3 0f 1f 40 00 66 66 66 66 90 55 48 89 e5 c6
Am now running 4.5.2 to see if the problem persists.