Apr 18 16:22:51 [my-hostname] kernel: [26131.670170] [drm] stuck on render ring
Apr 18 16:22:51 [my-hostname] kernel: [26131.670927] [drm] GPU HANG: ecode 7:0:0x85dffffc, in Xorg [26377], reason: Ring hung, action: reset
Apr 18 16:22:51 [my-hostname] kernel: [26131.673058] drm/i915: Resetting chip after gpu hang
Apr 18 16:22:57 [my-hostname] kernel: [26137.681795] [drm] stuck on render ring
Apr 18 16:22:57 [my-hostname] kernel: [26137.682567] [drm] GPU HANG: ecode 7:0:0x85dfbdf8, in Xorg [26377], reason: Ring hung, action: reset
Apr 18 16:22:57 [my-hostname] kernel: [26137.682596] ------------[ cut here ]------------
Apr 18 16:22:57 [my-hostname] kernel: [26137.682639] WARNING: CPU: 1 PID: 25758 at /build/linux-XwpX40/linux-4.4.0/drivers/gpu/drm/i915/intel_display.c:11287 intel_mmio_flip_work_func+0x38e/0x3d0 [i915]()
Apr 18 16:22:57 [my-hostname] kernel: [26137.682642] WARN_ON(__i915_wait_request(mmio_flip->req, mmio_flip->crtc->reset_counter, false, NULL, &mmio_flip->i915->rps.mmioflips))
Apr 18 16:22:57 [my-hostname] kernel: [26137.682643] Modules linked in: hid_generic md4 nls_utf8 cifs fscache ctr ccm rfcomm bnep pci_stub vboxpci(OE) vboxnetadp(OE) vboxnetflt(OE) binfmt_misc nls_iso8859_1 arc4 uvcvideo videobuf2_vmalloc videobuf2_memops videobuf2_v4l2 iwlmvm videobuf2_core hid_sensor_gyro_3d hid_sensor_rotation hp_wmi snd_hda_codec_hdmi v4l2_common hid_sensor_incl_3d sparse_keymap videodev hid_sensor_accel_3d hid_sensor_magn_3d hid_sensor_trigger industrialio_triggered_buffer kfifo_buf hid_multitouch industrialio mac80211 hid_sensor_iio_common media snd_hda_codec_realtek snd_hda_codec_generic btusb btrtl btbcm btintel intel_rapl bluetooth x86_pkg_temp_thermal intel_powerclamp snd_hda_intel kvm_intel kvm snd_hda_codec irqbypass snd_hda_core snd_hwdep iwlwifi snd_pcm input_leds joydev rtsx_pci_ms snd_seq_midi serio_raw cfg80211 memstick snd_seq_midi_event snd_rawmidi snd_seq snd_seq_device lpc_ich mei_me hp_accel lis3lv02d snd_timer shpchp mei input_polldev snd soundcore hp_wireless intel_smartconnect mac_hid coretemp vboxdrv(OE) sunrpc parport_pc ppdev lp parport autofs4 drbg ansi_cprng algif_skcipher af_alg hid_sensor_custom hid_sensor_hub usbhid hid dm_crypt rtsx_pci_sdmmc crct10dif_pclmul crc32_pclmul psmouse i915 aesni_intel aes_x86_64 lrw gf128mul glue_helper ablk_helper cryptd i2c_algo_bit ahci drm_kms_helper libahci syscopyarea sysfillrect sysimgblt r8169 fb_sys_fops mii rtsx_pci drm wmi video fjes
Apr 18 16:22:57 [my-hostname] kernel: [26137.682753] CPU: 1 PID: 25758 Comm: kworker/1:2 Tainted: G W OE 4.4.0-18-generic #34-Ubuntu
Apr 18 16:22:57 [my-hostname] kernel: [26137.682755] Hardware name: Hewlett-Packard HP ENVY 15 x360 PC /22D6, BIOS F.26 01/19/2015
Apr 18 16:22:57 [my-hostname] kernel: [26137.682786] Workqueue: events intel_mmio_flip_work_func [i915]
Apr 18 16:22:57 [my-hostname] kernel: [26137.682790] 0000000000000286 000000003dde356c ffff88034c1d7d20 ffffffff813e9243
Apr 18 16:22:57 [my-hostname] kernel: [26137.682794] ffff88034c1d7d68 ffffffffc0304a50 ffff88034c1d7d58 ffffffff81080f62
Apr 18 16:22:57 [my-hostname] kernel: [26137.682797] ffff880185d81ec0 ffff88035f256500 ffff88035f25ae00 0000000000000040
Apr 18 16:22:57 [my-hostname] kernel: [26137.682800] Call Trace:
Apr 18 16:22:57 [my-hostname] kernel: [26137.682808] [<ffffffff813e9243>] dump_stack+0x63/0x90
Apr 18 16:22:57 [my-hostname] kernel: [26137.682814] [<ffffffff81080f62>] warn_slowpath_common+0x82/0xc0
Apr 18 16:22:57 [my-hostname] kernel: [26137.682817] [<ffffffff81080ffc>] warn_slowpath_fmt+0x5c/0x80
Apr 18 16:22:57 [my-hostname] kernel: [26137.682822] [<ffffffff8102d8b0>] ? __switch_to+0x420/0x5a0
Apr 18 16:22:57 [my-hostname] kernel: [26137.682859] [<ffffffffc029dc9e>] intel_mmio_flip_work_func+0x38e/0x3d0 [i915]
Apr 18 16:22:57 [my-hostname] kernel: [26137.682865] [<ffffffff81099ff2>] process_one_work+0x162/0x480
Apr 18 16:22:57 [my-hostname] kernel: [26137.682868] [<ffffffff8109a35b>] worker_thread+0x4b/0x4c0
Apr 18 16:22:57 [my-hostname] kernel: [26137.682871] [<ffffffff8109a310>] ? process_one_work+0x480/0x480
Apr 18 16:22:57 [my-hostname] kernel: [26137.682875] [<ffffffff8109a310>] ? process_one_work+0x480/0x480
Apr 18 16:22:57 [my-hostname] kernel: [26137.682878] [<ffffffff810a0528>] kthread+0xd8/0xf0
Apr 18 16:22:57 [my-hostname] kernel: [26137.682880] [<ffffffff810a0450>] ? kthread_create_on_node+0x1e0/0x1e0
Apr 18 16:22:57 [my-hostname] kernel: [26137.682885] [<ffffffff8182474f>] ret_from_fork+0x3f/0x70
Apr 18 16:22:57 [my-hostname] kernel: [26137.682890] [<ffffffff810a0450>] ? kthread_create_on_node+0x1e0/0x1e0
Apr 18 16:22:57 [my-hostname] kernel: [26137.682892] ---[ end trace c0f775f4f8db7e2e ]---
Apr 18 16:22:57 [my-hostname] kernel: [26137.684726] drm/i915: Resetting chip after gpu hang
Apr 18 16:22:58 [my-hostname] gnome-session[27287]: (onboard:27531): Gdk-WARNING **: onboard: Fatal IO error 11 (Resource temporarily unavailable) on X server :0.
[cut out out a bunch more app-specific "fatal IO error" messages]
Apr 18 16:22:58 [my-hostname] gnome-session[27287]: Failed to connect to Mir: Failed to connect to server socket: No such file or directory
Apr 18 16:22:58 [my-hostname] gnome-session[27287]: Unable to init server: Could not connect: Connection refused
Apr 18 16:22:58 [my-hostname] gnome-session[27287]: (polkit-gnome-authentication-agent-1:28147): Gtk-WARNING **: cannot open display: :0
Apr 18 16:22:58 [my-hostname] org.freedesktop.Geoclue.Providers.UbuntuGeoIP[27036]: ** (ubuntu-geoip-provider:27436): WARNING **: SIGTERM recieved
Apr 18 16:22:58 [my-hostname] org.freedesktop.Geoclue.Providers.UbuntuGeoIP[27036]: (ubuntu-geoip-provider:27436): GLib-GObject-CRITICAL **: g_object_unref: assertion 'G_IS_OBJECT (object)' failed
Apr 18 16:22:58 [my-hostname] gnome-session[27287]: gnome-session-binary[27287]: WARNING: Lost name on bus: org.gnome.SessionManager
Apr 18 16:22:58 [my-hostname] gnome-session[27287]: gnome-session-binary[27287]: CRITICAL: We failed, but the fail whale is dead. Sorry....
Apr 18 16:22:58 [my-hostname] gnome-session-binary[27287]: WARNING: Lost name on bus: org.gnome.SessionManager
Apr 18 16:22:58 [my-hostname] gnome-session-binary[27287]: CRITICAL: We failed, but the fail whale is dead. Sorry....
Apr 18 16:22:58 [my-hostname] org.gnome.zeitgeist.SimpleIndexer[27036]: (zeitgeist-fts:27758): GLib-GIO-WARNING **: Error releasing name org.gnome.zeitgeist.SimpleIndexer: The connection is closed
Apr 18 16:22:58 [my-hostname] org.gnome.zeitgeist.SimpleIndexer[27036]: ** (zeitgeist-fts:27758): WARNING **: zeitgeist-fts.vala:252: The connection is closed
Apr 18 16:22:58 [my-hostname] org.gnome.zeitgeist.Engine[27036]: (zeitgeist-daemon:27743): GLib-GIO-WARNING **: Error releasing name org.gnome.zeitgeist.Engine: The connection is closed
Apr 18 16:22:58 [my-hostname] org.gnome.zeitgeist.Engine[27036]: #033[31m[20:22:58.917061 WARNING]#033[0m zeitgeist-daemon.vala:449: The connection is closed
Apr 18 16:22:59 [my-hostname] ofonod[1070]: ofonod[1070]: get_property_value: ERROR reply to Get
Apr 18 16:22:59 [my-hostname] ofonod[1070]: get_property_value: ERROR reply to Get
Apr 18 16:22:59 [my-hostname] systemd[1]: Started Session c11 of user lightdm.
Apr 18 16:22:59 [my-hostname] org.a11y.atspi.Registry[28208]: SpiRegistry daemon is running with well-known name - org.a11y.atspi.Registry
Apr 18 16:22:59 [my-hostname] rtkit-daemon[3530]: Successfully made thread 28301 of process 28301 (n/a) owned by '112' high priority at nice level -11.
Apr 18 16:22:59 [my-hostname] rtkit-daemon[3530]: Supervising 1 threads of 1 processes of 1 users.
Apr 18 16:22:59 [my-hostname] rtkit-daemon[3530]: Supervising 1 threads of 1 processes of 1 users.
Apr 18 16:22:59 [my-hostname] rtkit-daemon[3530]: Successfully made thread 28333 of process 28301 (n/a) owned by '112' RT at priority 5.
Apr 18 16:22:59 [my-hostname] rtkit-daemon[3530]: Supervising 2 threads of 1 processes of 1 users.
Apr 18 16:22:59 [my-hostname] org.gnome.ScreenSaver[28200]: ** (gnome-screensaver:28277): WARNING **: Couldn't get presence status: No such interface 'org.freedesktop.DBus.Properties' on object at path /org/gnome/SessionManager/Presence
Apr 18 16:22:59 [my-hostname] org.gnome.ScreenSaver[28200]: ** (gnome-screensaver:28277): WARNING **: screensaver already running in this session
Apr 18 16:22:59 [my-hostname] rtkit-daemon[3530]: Supervising 2 threads of 1 processes of 1 users.
Apr 18 16:22:59 [my-hostname] rtkit-daemon[3530]: Successfully made thread 28335 of process 28301 (n/a) owned by '112' RT at priority 5.
Apr 18 16:22:59 [my-hostname] rtkit-daemon[3530]: Supervising 3 threads of 1 processes of 1 users.
Apr 18 16:22:59 [my-hostname] rtkit-daemon[3530]: Supervising 3 threads of 1 processes of 1 users.
Apr 18 16:22:59 [my-hostname] rtkit-daemon[3530]: Successfully made thread 28337 of process 28301 (n/a) owned by '112' RT at priority 5.
Apr 18 16:22:59 [my-hostname] rtkit-daemon[3530]: Supervising 4 threads of 1 processes of 1 users.
Apr 18 16:22:59 [my-hostname] bluetoothd[1098]: Endpoint registered: sender=:1.665 path=/MediaEndpoint/A2DPSource
Apr 18 16:22:59 [my-hostname] bluetoothd[1098]: Endpoint registered: sender=:1.665 path=/MediaEndpoint/A2DPSink
[and the re-login...]
Apr 18 16:23:03 [my-hostname] org.gtk.vfs.Daemon[28200]: A connection to the bus can't be made
Apr 18 16:23:03 [my-hostname] console-kit-daemon[3512]: (process:28712): GLib-CRITICAL **: g_slice_set_config: assertion 'sys_page_size == 0' failed
Apr 18 16:23:03 [my-hostname] lightdm[1374]: ** (process:28235): WARNING **: Error getting XDG_RUNTIME_DIR from ConsoleKit: GDBus.Error:org.freedesktop.DBus.Error.UnknownMethod: Method "GetXDGRuntimeDir" with signature "" on interface "org.freedesktop.ConsoleKit.Session" doesn't exist
Apr 18 16:23:03 [my-hostname] lightdm[1374]: ** (lightdm:1374): WARNING **: Error activating ConsoleKit session: GDBus.Error:org.freedesktop.DBus.GLib.UnmappedError.CkVtMonitorError.Code0: Session is already active
Apr 18 16:23:03 [my-hostname] org.ayatana.bamf[28813]: bamfdaemon start/running, process 28874
Apr 18 16:23:05 [my-hostname] org.a11y.atspi.Registry[29070]: SpiRegistry daemon is running with well-known name - org.a11y.atspi.Registry
Apr 18 16:23:05 [my-hostname] gnome-session[29060]: (gnome-session-check-accelerated:29072): dconf-CRITICAL **: unable to create file '/home/[my-user]/.cache/dconf/user': Permission denied. dconf will not work properly.
Apr 18 16:23:05 [my-hostname] gnome-session[29060]: message repeated 2 times: [ (gnome-session-check-accelerated:29072): dconf-CRITICAL **: unable to create file '/home/[my-user]/.cache/dconf/user': Permission denied. dconf will not work properly.]
Apr 18 16:23:05 [my-hostname] gnome-session[29060]: gnome-session-binary[29060]: WARNING: Could not get session id for session. Check that logind is properly installed and pam_systemd is getting used at login.
Apr 18 16:23:05 [my-hostname] gnome-session-binary[29060]: WARNING: Could not get session id for session. Check that logind is properly installed and pam_systemd is getting used at login.
[truncated here, a whole bunch of dconf-related error messages follow, but I don't know if they're actually related or are a separate problem, since I've been swarmed by them occasionally when I'm *not* having the session-crashing gpu hang bug. ]