kernel: [ 242.381420] INFO: task kworker/u129:0:6 blocked for more than 120 seconds. kernel: [ 242.417101] Not tainted 4.15.0-041500rc8-generic #201801142030 kernel: [ 242.447495] "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kernel: [ 242.482715] kworker/u129:0 D 0 6 2 0x80000000 kernel: [ 242.482729] Workqueue: writeback wb_workfn (flush-8:0) kernel: [ 242.482731] Call Trace: kernel: [ 242.482744] __schedule+0x291/0x880 kernel: [ 242.482747] schedule+0x2c/0x80 kernel: [ 242.482751] io_schedule+0x16/0x40 kernel: [ 242.482756] get_request+0x2a4/0x7f0 kernel: [ 242.482761] ? wait_woken+0x80/0x80 kernel: [ 242.482765] blk_queue_bio+0x128/0x440 kernel: [ 242.482767] generic_make_request+0x11f/0x300 kernel: [ 242.482769] submit_bio+0x73/0x140 kernel: [ 242.482770] ? submit_bio+0x73/0x140 kernel: [ 242.482836] xfs_submit_ioend+0x87/0x1c0 [xfs] kernel: [ 242.482861] xfs_do_writepage+0x377/0x690 [xfs] kernel: [ 242.482868] write_cache_pages+0x209/0x4d0 kernel: [ 242.482891] ? xfs_vm_writepages+0xf0/0xf0 [xfs] kernel: [ 242.482913] xfs_vm_writepages+0xbe/0xf0 [xfs] kernel: [ 242.482915] do_writepages+0x48/0xe0 kernel: [ 242.482919] ? check_preempt_curr+0x2d/0x90 kernel: [ 242.482920] ? ttwu_do_wakeup+0x1e/0x140 kernel: [ 242.482924] __writeback_single_inode+0x45/0x330 kernel: [ 242.482926] ? __writeback_single_inode+0x45/0x330 kernel: [ 242.482927] ? try_to_wake_up+0x59/0x480 kernel: [ 242.482929] writeback_sb_inodes+0x1e1/0x510 kernel: [ 242.482932] __writeback_inodes_wb+0x67/0xb0 kernel: [ 242.482934] wb_writeback+0x26b/0x300 kernel: [ 242.482937] wb_workfn+0x180/0x410 kernel: [ 242.482939] ? wb_workfn+0x180/0x410 kernel: [ 242.482943] process_one_work+0x1ea/0x410 kernel: [ 242.482945] worker_thread+0x32/0x410 kernel: [ 242.482948] kthread+0x11e/0x140 kernel: [ 242.482949] ? process_one_work+0x410/0x410 kernel: [ 242.482951] ? kthread_create_worker_on_cpu+0x70/0x70 kernel: [ 242.482956] ret_from_fork+0x32/0x40
-- 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/1744163 Title: CPU offlining can trigger hangs with HP ProLiant DL360p Gen8. Status in linux package in Ubuntu: Triaged Status in linux source package in Artful: Triaged Status in linux source package in Bionic: Triaged Bug description: CPU offlining can trigger hangs with HP ProLiant DL360p Gen8 on Ubuntu 17.10. The hangs also occur with latest mainline kernel Linux 4.15-rc8. I bisected the upstream mainline kernel. This is a regression introduced by Linux 4.13-rc1 commit c5cb83bb337c25caae995d992d1cdf9b317f83de ("genirq/cpuhotplug: Handle managed IRQs on CPU hotplug"). https://github.com/torvalds/linux/commit/c5cb83bb337c25caae995d992d1cdf9b317f83de This test case to offline all CPUs except for CPU 0 can be used to trigger a hang. for i in $(seq 1 $(expr $(nproc --all) - 1)); do sudo sh -c "echo 0 > /sys/devices/system/cpu/cpu$i/online"; done To manage notifications about this bug go to: https://bugs.launchpad.net/ubuntu/+source/linux/+bug/1744163/+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