Public bug reported: I was using chromium when the whole system GUI stopped responding at 15:42. This corresponds to the system journal at that point:
Aug 20 15:42:56 dh3930 kernel: nouveau 0000:01:00.0: fifo: SCHED_ERROR 0a [CTXSW_TIMEOUT] Aug 20 15:42:56 dh3930 kernel: nouveau 0000:01:00.0: fifo: runlist 0: scheduled for recovery Aug 20 15:42:56 dh3930 kernel: nouveau 0000:01:00.0: fifo: channel 15: killed Aug 20 15:42:56 dh3930 kernel: nouveau 0000:01:00.0: fifo: engine 0: scheduled for recovery Aug 20 15:42:56 dh3930 kernel: nouveau 0000:01:00.0: compiz[7682]: channel 15 killed! Aug 20 15:45:50 dh3930 kernel: INFO: task kworker/u24:4:14623 blocked for more than 120 seconds. Aug 20 15:45:50 dh3930 kernel: Not tainted 4.15.0-32-generic #35-Ubuntu Aug 20 15:45:50 dh3930 kernel: "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. Aug 20 15:45:50 dh3930 kernel: kworker/u24:4 D 0 14623 2 0x80000000 Aug 20 15:45:50 dh3930 kernel: Workqueue: events_unbound nv50_disp_atomic_commit_work [nouveau] Aug 20 15:45:50 dh3930 kernel: Call Trace: Aug 20 15:45:50 dh3930 kernel: __schedule+0x291/0x8a0 Aug 20 15:45:50 dh3930 kernel: schedule+0x2c/0x80 Aug 20 15:45:50 dh3930 kernel: schedule_timeout+0x1cf/0x350 Aug 20 15:45:50 dh3930 kernel: ? nvif_object_ioctl+0x47/0x50 [nouveau] Aug 20 15:45:50 dh3930 kernel: ? nouveau_bo_rd32+0x2a/0x30 [nouveau] Aug 20 15:45:50 dh3930 kernel: ? nv84_fence_read+0x2e/0x30 [nouveau] Aug 20 15:45:50 dh3930 kernel: ? nouveau_fence_no_signaling+0x2a/0x80 [nouveau] Aug 20 15:45:50 dh3930 kernel: dma_fence_default_wait+0x1c7/0x260 Aug 20 15:45:50 dh3930 kernel: ? dma_fence_release+0xa0/0xa0 Aug 20 15:45:50 dh3930 kernel: dma_fence_wait_timeout+0x3e/0xf0 Aug 20 15:45:50 dh3930 kernel: drm_atomic_helper_wait_for_fences+0x63/0xc0 [drm_kms_helper] Aug 20 15:45:50 dh3930 kernel: nv50_disp_atomic_commit_tail+0x55/0x3b10 [nouveau] Aug 20 15:45:50 dh3930 kernel: nv50_disp_atomic_commit_work+0x12/0x20 [nouveau] Aug 20 15:45:50 dh3930 kernel: process_one_work+0x1de/0x410 Aug 20 15:45:50 dh3930 kernel: worker_thread+0x32/0x410 Aug 20 15:45:50 dh3930 kernel: kthread+0x121/0x140 Aug 20 15:45:50 dh3930 kernel: ? process_one_work+0x410/0x410 Aug 20 15:45:50 dh3930 kernel: ? kthread_create_worker_on_cpu+0x70/0x70 Aug 20 15:45:50 dh3930 kernel: ret_from_fork+0x35/0x40 The 'blocked for more than 120 seconds' message and call trace repeated every ~121 seconds until I rebooted. At that point, the following additional line appeared with the 'blocked for more than 120 seconds' message: Aug 20 16:01:51 dh3930 kernel: nouveau 0000:01:00.0: chromium- browse[14187]: failed to idle channel 20 [chromium-browse[14187]] ProblemType: Bug DistroRelease: Ubuntu 18.04 Package: linux-image-4.15.0-32-generic 4.15.0-32.35 ProcVersionSignature: Ubuntu 4.15.0-32.35-generic 4.15.18 Uname: Linux 4.15.0-32-generic x86_64 ApportVersion: 2.20.9-0ubuntu7.2 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: david 2460 F.... pulseaudio /dev/snd/controlC0: david 2460 F.... pulseaudio CurrentDesktop: Unity:Unity7:ubuntu Date: Mon Aug 20 16:07:40 2018 EcryptfsInUse: Yes HibernationDevice: RESUME=UUID=9e4f3d6a-f1b3-40c0-8c97-97d861a7ce11 InstallationDate: Installed on 2016-10-24 (664 days ago) InstallationMedia: Ubuntu 16.10 "Yakkety Yak" - Release amd64 (20161012.2) MachineType: System manufacturer System Product Name ProcFB: 0 nouveaufb ProcKernelCmdLine: BOOT_IMAGE=/@/boot/vmlinuz-4.15.0-32-generic root=UUID=311cc681-166d-47bd-847d-f41c81578c1a ro rootflags=subvol=@ quiet splash vt.handoff=1 RelatedPackageVersions: linux-restricted-modules-4.15.0-32-generic N/A linux-backports-modules-4.15.0-32-generic N/A linux-firmware 1.173.1 RfKill: SourcePackage: linux UpgradeStatus: Upgraded to bionic on 2018-05-01 (110 days ago) dmi.bios.date: 05/06/2014 dmi.bios.vendor: American Megatrends Inc. dmi.bios.version: 4701 dmi.board.asset.tag: To be filled by O.E.M. dmi.board.name: P9X79 dmi.board.vendor: ASUSTeK COMPUTER INC. dmi.board.version: Rev 1.xx dmi.chassis.asset.tag: Asset-1234567890 dmi.chassis.type: 3 dmi.chassis.vendor: Chassis Manufacture dmi.chassis.version: Chassis Version dmi.modalias: dmi:bvnAmericanMegatrendsInc.:bvr4701:bd05/06/2014:svnSystemmanufacturer:pnSystemProductName:pvrSystemVersion:rvnASUSTeKCOMPUTERINC.:rnP9X79:rvrRev1.xx:cvnChassisManufacture:ct3:cvrChassisVersion: dmi.product.family: To be filled by O.E.M. dmi.product.name: System Product Name dmi.product.version: System Version dmi.sys.vendor: System manufacturer ** Affects: linux (Ubuntu) Importance: Undecided Status: New ** Affects: xserver-xorg-video-nouveau (Ubuntu) Importance: Undecided Status: New ** Tags: amd64 apport-bug bionic ** Also affects: xserver-xorg-video-nouveau (Ubuntu) Importance: Undecided Status: New -- You received this bug notification because you are a member of Ubuntu-X, which is subscribed to xserver-xorg-video-nouveau in Ubuntu. https://bugs.launchpad.net/bugs/1788044 Title: task kworker blocked for more than 120 seconds nouveau To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1788044/+subscriptions _______________________________________________ Mailing list: https://launchpad.net/~ubuntu-x-swat Post to : ubuntu-x-swat@lists.launchpad.net Unsubscribe : https://launchpad.net/~ubuntu-x-swat More help : https://help.launchpad.net/ListHelp