INFO: task :9310 can't die for more than 143 seconds. R running task 28144 9310 8957 0x00004006 Call Trace: context_switch kernel/sched/core.c:3388 [inline] __schedule+0x8e9/0x1f30 kernel/sched/core.c:4081 Showing all locks held in the system: 1 lock held by khungtaskd/1081: #0: ffffffff88faccc0 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5334 1 lock held by rsyslogd/8821: #0: ffff88809a6ece20 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8911: #0: ffff888085c7b090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f452e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8912: #0: ffff88809e40a090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f492e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8913: #0: ffff888093916090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f312e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8914: #0: ffff888099c9d090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f532e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8915: #0: ffff8880985ac090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f4f2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8916: #0: ffff8880997f6090 (&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/8917: #0: ffff888094d55090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f212e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1081 Comm: khungtaskd Not tainted 5.4.0-rc7-next-20191115 #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+0x197/0x210 lib/dump_stack.c:118 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: 840 Comm: kworker/u4:5 Not tainted 5.4.0-rc7-next-20191115 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: bat_events batadv_nc_worker RIP: 0010:mark_held_locks+0x98/0xf0 kernel/locking/lockdep.c:3357 Code: f8 48 89 fa 48 c1 e8 03 83 e2 07 42 0f b6 04 30 38 d0 7f 04 84 c0 75 4c 0f b6 46 22 89 c2 83 e2 03 80 fa 01 44 89 e2 83 da ff 04 74 0c 4c 89 ef e8 3c ed ff ff 85 c0 74 11 83 c3 01 41 39 9d RSP: 0018:ffff8880a838fb80 EFLAGS: 00000017 RAX: 0000000000000004 RBX: 0000000000000001 RCX: 0000000000000006 RDX: 0000000000000006 RSI: ffff8880a8380948 RDI: ffff8880a838096a RBP: ffff8880a838fbb0 R08: 1ffffffff14f4b4a R09: fffffbfff14f4b4b R10: fffffbfff14f4b4a R11: ffffffff8a7a5a57 R12: 0000000000000006 R13: ffff8880a8380080 R14: dffffc0000000000 R15: ffff8880a8380920 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fa3b3b5b000 CR3: 000000009fca8000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __trace_hardirqs_on_caller kernel/locking/lockdep.c:3389 [inline] lockdep_hardirqs_on+0x421/0x5e0 kernel/locking/lockdep.c:3434 trace_hardirqs_on+0x67/0x240 kernel/trace/trace_preemptirq.c:31 __local_bh_enable_ip+0x15a/0x270 kernel/softirq.c:194 __raw_spin_unlock_bh include/linux/spinlock_api_smp.h:176 [inline] _raw_spin_unlock_bh+0x2c/0x30 kernel/locking/spinlock.c:207 spin_unlock_bh include/linux/spinlock.h:383 [inline] batadv_nc_purge_paths+0x265/0x370 net/batman-adv/network-coding.c:470 batadv_nc_worker+0x2ca/0x760 net/batman-adv/network-coding.c:721 process_one_work+0x9af/0x1740 kernel/workqueue.c:2264 worker_thread+0x98/0xe40 kernel/workqueue.c:2410 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352