Since it's a regression, would it be possible for you to do a kernel bisection?
First, find the last -rc kernel works and the first -rc kernel doesn’t work from http://kernel.ubuntu.com/~kernel-ppa/mainline/ Then, $ sudo apt build-dep linux $ git clone git://git.kernel.org/pub/scm/linux/kernel/git/torvalds/linux.git $ cd linux $ git bisect start $ git bisect good $(the working version you found) $ git bisect bad $(the non-working version found) $ make localmodconfig $ make -j`nproc` deb-pkg Install the newly built kernel, then reboot with it. If it still have the same issue, $ git bisect bad Otherwise, $ git bisect good Repeat to "make -j`nproc` deb-pkg" until you find the offending commit. -- You received this bug notification because you are a member of Kernel Packages, which is subscribed to linux in Ubuntu. https://bugs.launchpad.net/bugs/1878919 Title: kworker/0:1+kacpid uses 100% of one CPU core Status in linux package in Ubuntu: Incomplete Bug description: At some point, kworker/0:1+kacpid starts using 100% of one CPU's core; this can be seen in the top command. I captured some performance data via the following command: $ perf record -g -a sleep 10 Then, perf report gives the following: Samples: 75K of event 'cycles', Event count (approx.): 44710762967 Children Self Command Shared Object Symbol + 65,46% 0,00% kworker/0:1+kac [kernel.kallsyms] [k] ret_from_fork + 65,46% 0,00% kworker/0:1+kac [kernel.kallsyms] [k] kthread + 65,46% 0,00% kworker/0:1+kac [kernel.kallsyms] [k] worker_thread + 65,44% 0,00% kworker/0:1+kac [kernel.kallsyms] [k] process_one_work + 65,44% 0,00% kworker/0:1+kac [kernel.kallsyms] [k] acpi_os_execute_deferred + 65,33% 0,00% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ev_asynch_execute_gpe_method + 65,32% 0,00% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ns_evaluate + 65,26% 0,00% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ps_execute_method + 65,16% 0,06% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ps_parse_aml + 61,00% 0,94% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ps_parse_loop + 37,83% 0,75% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ds_exec_end_op + 18,33% 0,04% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ds_evaluate_name_path + 16,12% 0,23% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ns_lookup + 15,79% 0,20% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ns_search_and_enter + 15,23% 14,99% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ns_search_one_scope + 14,38% 0,00% swapper [kernel.kallsyms] [k] secondary_startup_64 + 14,38% 0,02% swapper [kernel.kallsyms] [k] cpu_startup_entry + 14,31% 0,12% swapper [kernel.kallsyms] [k] do_idle + 13,79% 0,00% swapper [kernel.kallsyms] [k] start_secondary + 12,92% 0,03% swapper [kernel.kallsyms] [k] call_cpuidle + 12,89% 0,00% swapper [kernel.kallsyms] [k] cpuidle_enter + 12,85% 0,05% swapper [kernel.kallsyms] [k] cpuidle_enter_state + 12,35% 2,15% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ut_update_object_reference + 12,05% 0,28% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ex_resolve_to_value + 10,40% 0,04% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ex_resolve_node_to_value + 9,90% 0,44% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ds_create_operand + 9,50% 0,05% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ex_read_data_from_field + 9,39% 0,06% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ex_field_datum_io + 9,26% 0,12% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ex_access_region + 9,23% 0,08% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ps_get_next_namepath + 9,15% 1,28% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ut_update_ref_count.part.0 + 9,01% 0,08% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ev_address_space_dispatch + 8,96% 0,14% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ex_extract_from_field + 8,78% 7,70% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ex_system_memory_space_handler + 7,81% 0,22% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ut_remove_reference + 6,63% 6,43% swapper [kernel.kallsyms] [k] intel_idle + 5,31% 0,68% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ps_create_op + 5,12% 0,08% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ut_add_reference + 4,89% 0,07% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ds_delete_result_if_not_used + 4,71% 0,09% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ds_do_implicit_return + 4,61% 0,17% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ds_is_result_used + 3,91% 3,62% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ut_track_stack_ptr + 3,83% 0,31% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ps_complete_op + 3,39% 0,23% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ps_alloc_op + 3,25% 3,20% kworker/0:1+kac [kernel.kallsyms] [k] _raw_spin_lock_irqsave + 3,23% 0,24% kworker/0:1+kac [kernel.kallsyms] [k] acpi_os_acquire_lock + 3,17% 0,00% kworker/u16:10- [kernel.kallsyms] [k] ret_from_fork + 3,17% 0,00% kworker/u16:10- [kernel.kallsyms] [k] kthread + 3,17% 0,00% kworker/u16:10- [kernel.kallsyms] [k] worker_thread + 3,17% 0,00% kworker/u16:10- [kernel.kallsyms] [k] process_one_work + 3,16% 0,00% kworker/u16:10- [kernel.kallsyms] [k] nv50_disp_atomic_commit_work + 3,14% 0,00% kworker/u16:10- [kernel.kallsyms] [k] nv50_disp_atomic_commit_tail + 3,12% 1,69% kworker/0:1+kac [kernel.kallsyms] [k] acpi_ut_trace_ptr + 3,09% 0,00% kworker/u16:10- [kernel.kallsyms] [k] nv50_wndw_wait_armed + 3,09% 0,00% kworker/u16:10- [kernel.kallsyms] [k] hid_hw_stop + 3,05% 0,01% swapper [kernel.kallsyms] [k] ret_from_intr + 3,05% 0,00% swapper [kernel.kallsyms] [k] do_IRQ + 3,02% 0,00% swapper [kernel.kallsyms] [k] handle_irq_event + 3,02% 0,00% swapper [kernel.kallsyms] [k] handle_irq_event_percpu There is the following in dmesg, I do not know whether it's related to the issue: [31046.072827] pci_bus 0000:02: Allocating resources [31046.072949] pcieport 0000:00:1c.0: bridge window [io 0x1000-0x0fff] to [bus 02] add_size 1000 [31046.072951] pcieport 0000:00:1c.0: bridge window [mem 0x00100000-0x000fffff 64bit pref] to [bus 02] add_size 200000 add_align 100000 [31046.072957] pci_bus 0000:05: Allocating resources [31046.072965] pcieport 0000:00:1c.0: BAR 15: assigned [mem 0xaa000000-0xaa1fffff 64bit pref] [31046.072968] pcieport 0000:00:1c.0: BAR 13: assigned [io 0x2000-0x2fff] [31046.073030] pcieport 0000:00:1c.4: AER: Corrected error received: 0000:00:1c.4 [31046.073037] pcieport 0000:00:1c.4: AER: PCIe Bus Error: severity=Corrected, type=Data Link Layer, (Transmitter ID) [31046.073039] pcieport 0000:00:1c.4: AER: device [8086:a114] error status/mask=00001000/00002000 [31046.073041] pcieport 0000:00:1c.4: AER: [12] Timeout [31046.073046] pcieport 0000:00:1c.4: AER: Corrected error received: 0000:00:1c.4 [31046.073050] pcieport 0000:00:1c.4: AER: can't find device of ID00e4 [31090.841307] pcieport 0000:00:1c.4: AER: Corrected error received: 0000:00:1c.4 [31090.841311] pcieport 0000:00:1c.4: AER: PCIe Bus Error: severity=Corrected, type=Physical Layer, (Receiver ID) [31090.841313] pcieport 0000:00:1c.4: AER: device [8086:a114] error status/mask=00000001/00002000 [31090.841315] pcieport 0000:00:1c.4: AER: [ 0] RxErr [31091.128072] pci_bus 0000:02: Allocating resources [31091.128184] pci_bus 0000:05: Allocating resources ProblemType: Bug DistroRelease: Ubuntu 20.04 Package: linux-generic 5.4.0.29.34 ProcVersionSignature: Ubuntu 5.4.0-29.33-generic 5.4.30 Uname: Linux 5.4.0-29-generic x86_64 ApportVersion: 2.20.11-0ubuntu27 Architecture: amd64 AudioDevicesInUse: USER PID ACCESS COMMAND /dev/snd/controlC1: mavi 2209 F.... pulseaudio /dev/snd/controlC0: mavi 2209 F.... pulseaudio /dev/snd/controlC2: mavi 2209 F.... pulseaudio CasperMD5CheckResult: skip CurrentDesktop: ubuntu:GNOME Date: Fri May 15 16:33:39 2020 HibernationDevice: RESUME=/dev/mapper/vg0-lv0--swap InstallationDate: Installed on 2016-09-05 (1348 days ago) InstallationMedia: Ubuntu-Server 16.04.1 LTS "Xenial Xerus" - Release amd64 (20160719) MachineType: LENOVO 20EN0005MS ProcFB: 0 nouveaudrmfb ProcKernelCmdLine: BOOT_IMAGE=/vmlinuz-5.4.0-29-generic root=/dev/mapper/vg0-lv1--root ro splash ipv6.disable=1 nouveau.modeset=1 vt.handoff=7 RelatedPackageVersions: linux-restricted-modules-5.4.0-29-generic N/A linux-backports-modules-5.4.0-29-generic N/A linux-firmware 1.187 SourcePackage: linux UpgradeStatus: Upgraded to focal on 2020-03-20 (55 days ago) dmi.bios.date: 12/06/2019 dmi.bios.vendor: LENOVO dmi.bios.version: N1EET87W (1.60 ) dmi.board.asset.tag: Not Available dmi.board.name: 20EN0005MS dmi.board.vendor: LENOVO dmi.board.version: SDK0J40705 WIN dmi.chassis.asset.tag: No Asset Information dmi.chassis.type: 10 dmi.chassis.vendor: LENOVO dmi.chassis.version: None dmi.modalias: dmi:bvnLENOVO:bvrN1EET87W(1.60):bd12/06/2019:svnLENOVO:pn20EN0005MS:pvrThinkPadP50:rvnLENOVO:rn20EN0005MS:rvrSDK0J40705WIN:cvnLENOVO:ct10:cvrNone: dmi.product.family: ThinkPad P50 dmi.product.name: 20EN0005MS dmi.product.sku: LENOVO_MT_20EN_BU_Think_FM_ThinkPad P50 dmi.product.version: ThinkPad P50 dmi.sys.vendor: LENOVO To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1878919/+subscriptions -- Mailing list: https://launchpad.net/~kernel-packages Post to : kernel-packages@lists.launchpad.net Unsubscribe : https://launchpad.net/~kernel-packages More help : https://help.launchpad.net/ListHelp
