This has been affecting me approximately every 1-2 hours. Full details and discussion can be found http://askubuntu.com/questions/838855/crashing-freezing-hanging-on-remove-stuck-pageflip at that stack overflow Q/A. 

Macbook Pro A5102
OS: Ubuntu 16.04 LTS
Memory: 7.7GiB
Processor: Intel Core i5-5257u CPU @ 2.7GHz x 4
Graphics: Intel Iris 6100 (Broadwell GT3)
Os type: 64-bit
Disk: 37.0GB
uname -a: Linux caleb-ubuntu 4.4.0-43-generic #63-Ubuntu SMP Wed Oct 12 13:48:03 UTC 2016 x86_64 x86_64 x86_64 GNU/Linux
uname -r: 4.4.0-43-generic

Oct 19 11:13:18 caleb-ubuntu smartd[693]: Device: /dev/sda [SAT], SMART Usage Attribute: 194 Temperature_Celsius changed from 54 to 55
Oct 19 11:15:23 caleb-ubuntu kernel: [ 1928.576209] thunderbolt 0000:07:00.0: resetting error on 0:b.
Oct 19 11:15:23 caleb-ubuntu kernel: [ 1928.576223] thunderbolt 0000:07:00.0: 0:b: hotplug: scanning
Oct 19 11:15:23 caleb-ubuntu kernel: [ 1928.576226] thunderbolt 0000:07:00.0: 0:b: hotplug: no switch found

Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112344] ------------[ cut here ]------------
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112370] WARNING: CPU: 2 PID: 1033 at /build/linux-e0bh4_/linux-4.4.0/drivers/gpu/drm/i915/intel_display.c:3963 intel_crtc_wait_for_pending_flips+0x1e2/0x240 [i915]()
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112371] WARN_ON(wait_event_timeout(dev_priv->pending_flip_queue, !intel_crtc_has_pending_flip(crtc), 60*HZ) == 0)
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112373] Modules linked in: btrfs xor raid6_pq ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c cpuid rfcomm nvram bnep btusb btrtl btbcm joydev btintel input_leds bcm5974 bluetooth msr binfmt_misc nls_iso8859_1 applesmc intel_rapl x86_pkg_temp_thermal input_polldev intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul brcmfmac brcmutil snd_hda_codec_cirrus cfg80211 snd_hda_codec_generic aesni_intel aes_x86_64 lrw snd_hda_codec_hdmi gf128mul glue_helper ablk_helper cryptd bdc_pci thunderbolt snd_hda_intel snd_hda_codec lpc_ich intel_pch_thermal shpchp mei_me snd_hda_core mei snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi acpi_als kfifo_buf snd_seq sbs industrialio sbshc snd_seq_device snd_timer spi_pxa2xx_platform apple_bl snd soundcore mac_hid parport_pc ppdev lp parport autofs4 hid_apple hid_generic usbhid hid i915 i2c_algo_bit drm_kms_helper syscopyarea ahci sysfillrect uas libahci sysimgblt fb_sys_fops usb_storage drm fjes video
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112414] CPU: 2 PID: 1033 Comm: Xorg Not tainted 4.4.0-42-generic #62-Ubuntu
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112416] Hardware name: Apple Inc. MacBookPro12,1/Mac-E43C1C25D4880AD6, BIOS MBP121.88Z.0167.B16.1602111810 02/11/2016
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112417]  0000000000000286 000000004413e07b ffff88003533faa0 ffffffff813f1f83
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112419]  ffff88003533fae8 ffffffffc020eab8 ffff88003533fad8 ffffffff81081212
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112420]  ffff880264f629a8 ffff8800357b9030 ffff880264822000 ffff880264f62800
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112421] Call Trace:
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112426]  [<ffffffff813f1f83>] dump_stack+0x63/0x90
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112428]  [<ffffffff81081212>] warn_slowpath_common+0x82/0xc0
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112430]  [<ffffffff810812ac>] warn_slowpath_fmt+0x5c/0x80
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112432]  [<ffffffff810c3935>] ? finish_wait+0x55/0x70
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112447]  [<ffffffffc01a92a2>] intel_crtc_wait_for_pending_flips+0x1e2/0x240 [i915]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112449]  [<ffffffff810c3dd0>] ? wake_atomic_t_function+0x60/0x60
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112461]  [<ffffffffc01aa521>] intel_pre_plane_update+0x111/0x140 [i915]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112473]  [<ffffffffc01aacf2>] intel_atomic_commit+0x352/0x6f0 [i915]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112488]  [<ffffffffc003cbde>] ? drm_atomic_check_only+0x18e/0x590 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112499]  [<ffffffffc003d017>] drm_atomic_commit+0x37/0x60 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112505]  [<ffffffffc0104939>] drm_atomic_helper_disable_plane+0xa9/0xf0 [drm_kms_helper]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112514]  [<ffffffffc002c269>] __setplane_internal+0x169/0x250 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112524]  [<ffffffffc003b79a>] ? drm_modeset_lock_all_ctx+0x9a/0xb0 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112533]  [<ffffffffc0030056>] drm_mode_setplane+0x136/0x1b0 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112540]  [<ffffffffc0021752>] drm_ioctl+0x152/0x540 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112549]  [<ffffffffc002ff20>] ? drm_plane_check_pixel_format+0x50/0x50 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112553]  [<ffffffff8122122f>] do_vfs_ioctl+0x29f/0x490
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112555]  [<ffffffff8120fdd1>] ? __sb_end_write+0x21/0x30
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112557]  [<ffffffff8120d9dd>] ? vfs_write+0x15d/0x1a0
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112558]  [<ffffffff81221499>] SyS_ioctl+0x79/0x90
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112561]  [<ffffffff818318b2>] entry_SYSCALL_64_fastpath+0x16/0x71
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112562] ---[ end trace c2690206b3e3a010 ]---
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112563] ------------[ cut here ]------------
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112580] WARNING: CPU: 2 PID: 1033 at /build/linux-e0bh4_/linux-4.4.0/drivers/gpu/drm/i915/intel_display.c:3968 intel_crtc_wait_for_pending_flips+0x233/0x240 [i915]()
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112581] Removing stuck page flip
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112581] Modules linked in: btrfs xor raid6_pq ufs qnx4 hfsplus hfs minix ntfs msdos jfs xfs libcrc32c cpuid rfcomm nvram bnep btusb btrtl btbcm joydev btintel input_leds bcm5974 bluetooth msr binfmt_misc nls_iso8859_1 applesmc intel_rapl x86_pkg_temp_thermal input_polldev intel_powerclamp coretemp kvm_intel kvm irqbypass crct10dif_pclmul crc32_pclmul brcmfmac brcmutil snd_hda_codec_cirrus cfg80211 snd_hda_codec_generic aesni_intel aes_x86_64 lrw snd_hda_codec_hdmi gf128mul glue_helper ablk_helper cryptd bdc_pci thunderbolt snd_hda_intel snd_hda_codec lpc_ich intel_pch_thermal shpchp mei_me snd_hda_core mei snd_hwdep snd_pcm snd_seq_midi snd_seq_midi_event snd_rawmidi acpi_als kfifo_buf snd_seq sbs industrialio sbshc snd_seq_device snd_timer spi_pxa2xx_platform apple_bl snd soundcore mac_hid parport_pc ppdev lp parport autofs4 hid_apple hid_generic usbhid hid i915 i2c_algo_bit drm_kms_helper syscopyarea ahci sysfillrect uas libahci sysimgblt fb_sys_fops usb_storage drm fjes video
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112610] CPU: 2 PID: 1033 Comm: Xorg Tainted: G        W       4.4.0-42-generic #62-Ubuntu
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112610] Hardware name: Apple Inc. MacBookPro12,1/Mac-E43C1C25D4880AD6, BIOS MBP121.88Z.0167.B16.1602111810 02/11/2016
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112611]  0000000000000086 000000004413e07b ffff88003533faa0 ffffffff813f1f83
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112613]  ffff88003533fae8 ffffffffc020eab8 ffff88003533fad8 ffffffff81081212
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112614]  ffff880264f629a8 ffff8800357b9030 ffff880264822000 ffff880264f62800
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112616] Call Trace:
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112618]  [<ffffffff813f1f83>] dump_stack+0x63/0x90
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112620]  [<ffffffff81081212>] warn_slowpath_common+0x82/0xc0
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112622]  [<ffffffff810812ac>] warn_slowpath_fmt+0x5c/0x80
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112624]  [<ffffffff810c3935>] ? finish_wait+0x55/0x70
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112639]  [<ffffffffc01a92f3>] intel_crtc_wait_for_pending_flips+0x233/0x240 [i915]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112641]  [<ffffffff810c3dd0>] ? wake_atomic_t_function+0x60/0x60
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112657]  [<ffffffffc01aa521>] intel_pre_plane_update+0x111/0x140 [i915]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112672]  [<ffffffffc01aacf2>] intel_atomic_commit+0x352/0x6f0 [i915]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112683]  [<ffffffffc003cbde>] ? drm_atomic_check_only+0x18e/0x590 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112694]  [<ffffffffc003d017>] drm_atomic_commit+0x37/0x60 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112699]  [<ffffffffc0104939>] drm_atomic_helper_disable_plane+0xa9/0xf0 [drm_kms_helper]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112707]  [<ffffffffc002c269>] __setplane_internal+0x169/0x250 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112717]  [<ffffffffc003b79a>] ? drm_modeset_lock_all_ctx+0x9a/0xb0 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112727]  [<ffffffffc0030056>] drm_mode_setplane+0x136/0x1b0 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112734]  [<ffffffffc0021752>] drm_ioctl+0x152/0x540 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112743]  [<ffffffffc002ff20>] ? drm_plane_check_pixel_format+0x50/0x50 [drm]
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112745]  [<ffffffff8122122f>] do_vfs_ioctl+0x29f/0x490
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112746]  [<ffffffff8120fdd1>] ? __sb_end_write+0x21/0x30
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112748]  [<ffffffff8120d9dd>] ? vfs_write+0x15d/0x1a0
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112749]  [<ffffffff81221499>] SyS_ioctl+0x79/0x90
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112751]  [<ffffffff818318b2>] entry_SYSCALL_64_fastpath+0x16/0x71
Oct 19 11:15:49 caleb-ubuntu kernel: [ 1954.112752] ---[ end trace c2690206b3e3a011 ]---
[drm:intel_dp_link_training_clock_recovery [i915]] *ERROR* failed to enable link training
Oct 19 11:15:56 caleb-ubuntu kernel: [ 1961.138660] [drm:intel_dp_link_training_channel_equalization [i915]] *ERROR* failed to start channel equalization

Oct 19 11:16:04 caleb-ubuntu kernel: [ 1969.019894] thunderbolt 0000:07:00.0: resetting error on 0:b.
Oct 19 11:16:04 caleb-ubuntu kernel: [ 1969.019905] thunderbolt 0000:07:00.0: 0:b: got unplug event for disconnected port, ignoring