INFO: task khugepaged:1083 blocked for more than 143 seconds. Not tainted 5.4.0-rc5-next-20191031 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. khugepaged D27224 1083 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x94a/0x1e70 kernel/sched/core.c:4070 schedule+0xdc/0x2b0 kernel/sched/core.c:4144 io_schedule+0x1c/0x70 kernel/sched/core.c:5788 wait_on_page_bit_common mm/filemap.c:1175 [inline] __lock_page+0x422/0xab0 mm/filemap.c:1383 lock_page include/linux/pagemap.h:480 [inline] mpage_prepare_extent_to_map+0xb3f/0xf90 fs/ext4/inode.c:2668 ext4_writepages+0x954/0x2e70 fs/ext4/inode.c:2822 ? 0xffffffff81000000 do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 __filemap_fdatawrite_range+0x2bc/0x3b0 mm/filemap.c:421 __filemap_fdatawrite mm/filemap.c:429 [inline] filemap_flush+0x24/0x30 mm/filemap.c:456 collapse_file+0x36b1/0x41a0 mm/khugepaged.c:1652 khugepaged_scan_file mm/khugepaged.c:1890 [inline] khugepaged_scan_mm_slot mm/khugepaged.c:1988 [inline] khugepaged_do_scan mm/khugepaged.c:2072 [inline] khugepaged+0x2da9/0x4360 mm/khugepaged.c:2117 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Showing all locks held in the system: 4 locks held by kworker/u4:3/307: #0: ffff88821b348d28 ((wq_completion)writeback){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff88821b348d28 ((wq_completion)writeback){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff88821b348d28 ((wq_completion)writeback){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff88821b348d28 ((wq_completion)writeback){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff88821b348d28 ((wq_completion)writeback){+.+.}, at: set_work_data kernel/workqueue.c:614 [inline] #0: ffff88821b348d28 ((wq_completion)writeback){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:641 [inline] #0: ffff88821b348d28 ((wq_completion)writeback){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2234 #1: ffff8880a8d5fdc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2238 #2: ffff88809acd80d8 (&type->s_umount_key#32){++++}, at: trylock_super+0x22/0x110 fs/super.c:418 #3: ffff88809acda990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 1 lock held by khungtaskd/1067: #0: ffffffff88faba40 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5336 1 lock held by khugepaged/1083: #0: ffff88809acda990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 2 locks held by getty/8790: #0: ffff888095d54090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f1d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8791: #0: ffff8880a876a090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f412e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8792: #0: ffff88809515a090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f252e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8793: #0: ffff88809a075090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f352e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8794: #0: ffff88809aba0090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f292e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8795: #0: ffff8880a0454090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f3d2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8796: #0: ffff88809abb2090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f112e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by syz-executor.4/8935: #0: ffff88809acd80d8 (&type->s_umount_key#32){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:690 #1: ffff8880a23606c8 (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:343 [inline] #1: ffff8880a23606c8 (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x1a5/0xb50 fs/fs-writeback.c:2550 2 locks held by syz-executor.4/8939: #0: ffff88809acd80d8 (&type->s_umount_key#32){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:690 #1: ffff8880a23606c8 (&bdi->wb_switch_rwsem){+.+.}, at: bdi_down_write_wb_switch_rwsem fs/fs-writeback.c:343 [inline] #1: ffff8880a23606c8 (&bdi->wb_switch_rwsem){+.+.}, at: sync_inodes_sb+0x1a5/0xb50 fs/fs-writeback.c:2550 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1067 Comm: khungtaskd Not tainted 5.4.0-rc5-next-20191031 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Call Trace: __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x172/0x1f0 lib/dump_stack.c:113 nmi_cpu_backtrace.cold+0x70/0xb2 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x23b/0x28b lib/nmi_backtrace.c:62 arch_trigger_cpumask_backtrace+0x14/0x20 arch/x86/kernel/apic/hw_nmi.c:38 trigger_all_cpu_backtrace include/linux/nmi.h:146 [inline] check_hung_uninterruptible_tasks kernel/hung_task.c:269 [inline] watchdog+0xc8f/0x1350 kernel/hung_task.c:353 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 PID: 8882 Comm: kworker/u4:6 Not tainted 5.4.0-rc5-next-20191031 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:756 [inline] RIP: 0010:lock_acquire+0x20b/0x410 kernel/locking/lockdep.c:4490 Code: 9c 08 00 00 00 00 00 00 48 c1 e8 03 80 3c 10 00 0f 85 d3 01 00 00 48 83 3d e1 8f 99 07 00 0f 84 53 01 00 00 48 8b 7d c8 57 9d <0f> 1f 44 00 00 48 8d 65 d8 5b 41 5c 41 5d 41 5e 41 5f 5d c3 65 8b RSP: 0018:ffff8880608f7c08 EFLAGS: 00000286 RAX: 1ffffffff11e643c RBX: ffff8880608e2340 RCX: ffffffff81593710 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000286 RBP: ffff8880608f7c50 R08: 1ffffffff14f3d34 R09: fffffbfff14f3d35 R10: ffff8880608e2c30 R11: ffff8880608e2340 R12: ffffffff88faba40 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000000957e6000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: rcu_lock_acquire include/linux/rcupdate.h:208 [inline] rcu_read_lock include/linux/rcupdate.h:617 [inline] batadv_nc_process_nc_paths.part.0+0xe4/0x3c0 net/batman-adv/network-coding.c:686 batadv_nc_process_nc_paths net/batman-adv/network-coding.c:678 [inline] batadv_nc_worker+0x54b/0x760 net/batman-adv/network-coding.c:727 process_one_work+0x9af/0x1740 kernel/workqueue.c:2263 worker_thread+0x98/0xe40 kernel/workqueue.c:2409 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352