INFO: task kworker/u4:7:8031 blocked for more than 143 seconds.
Not tainted 5.0.0+ #122
"echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message.
kworker/u4:7 D25472 8031 2 0x80000000
Workqueue: netns cleanup_net
Call Trace:
context_switch kernel/sched/core.c:2877 [inline]
__schedule+0x817/0x1cc0 kernel/sched/core.c:3518
schedule+0x92/0x180 kernel/sched/core.c:3562
schedule_timeout+0x8ca/0xfd0 kernel/time/timer.c:1779
do_wait_for_common kernel/sched/completion.c:83 [inline]
__wait_for_common kernel/sched/completion.c:104 [inline]
wait_for_common kernel/sched/completion.c:115 [inline]
wait_for_completion+0x29c/0x440 kernel/sched/completion.c:136
rcu_barrier+0x1b8/0x270 kernel/rcu/tree.c:3262
netdev_run_todo+0x113/0x7d0 net/core/dev.c:8942
rtnl_unlock+0xe/0x10 net/core/rtnetlink.c:116
ip_tunnel_delete_nets+0x423/0x5f0 net/ipv4/ip_tunnel.c:1127
vti_exit_batch_net+0x23/0x30 net/ipv4/ip_vti.c:495
ops_exit_list.isra.0+0x105/0x160 net/core/net_namespace.c:156
cleanup_net+0x3fb/0x960 net/core/net_namespace.c:551
process_one_work+0x98e/0x1790 kernel/workqueue.c:2269
worker_thread+0x98/0xe40 kernel/workqueue.c:2415
kthread+0x357/0x430 kernel/kthread.c:253
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Showing all locks held in the system:
4 locks held by ksoftirqd/0/9:
1 lock held by khungtaskd/1040:
#0: 000000006c16abbd (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5061
1 lock held by rsyslogd/7608:
#0: 00000000f3eb9d60 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801
2 locks held by getty/7698:
#0: 00000000df6cfae5 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
#1: 000000006303e2ae (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7699:
#0: 000000004d179c31 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
#1: 00000000a757687c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7700:
#0: 00000000f133bbea (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
#1: 000000002ea15b5c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7701:
#0: 0000000033954ce2 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
#1: 00000000fff9d2d4 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7702:
#0: 00000000b9c19ceb (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
#1: 0000000061d237e1 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7703:
#0: 000000009ec0779a (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
#1: 00000000e8667a15 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
2 locks held by getty/7704:
#0: 0000000056bd7541 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341
#1: 00000000d369bc72 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156
4 locks held by kworker/u4:7/8031:
#0: 000000003e2f55aa ((wq_completion)netns){+.+.}, at: __write_once_size include/linux/compiler.h:220 [inline]
#0: 000000003e2f55aa ((wq_completion)netns){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline]
#0: 000000003e2f55aa ((wq_completion)netns){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline]
#0: 000000003e2f55aa ((wq_completion)netns){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline]
#0: 000000003e2f55aa ((wq_completion)netns){+.+.}, at: set_work_data kernel/workqueue.c:619 [inline]
#0: 000000003e2f55aa ((wq_completion)netns){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:646 [inline]
#0: 000000003e2f55aa ((wq_completion)netns){+.+.}, at: process_one_work+0x87e/0x1790 kernel/workqueue.c:2240
#1: 00000000cc943d05 (net_cleanup_work){+.+.}, at: process_one_work+0x8b4/0x1790 kernel/workqueue.c:2244
#2: 000000009d492749 (pernet_ops_rwsem){++++}, at: cleanup_net+0xae/0x960 net/core/net_namespace.c:518
#3: 000000000fba9d75 (rcu_state.barrier_mutex){+.+.}, at: rcu_barrier+0x30/0x270 kernel/rcu/tree.c:3197
=============================================
NMI backtrace for cpu 1
CPU: 1 PID: 1040 Comm: khungtaskd Not tainted 5.0.0+ #122
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+0x63/0xa4 lib/nmi_backtrace.c:101
nmi_trigger_cpumask_backtrace+0x1be/0x236 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:204 [inline]
watchdog+0x9b7/0xec0 kernel/hung_task.c:288
kthread+0x357/0x430 kernel/kthread.c:253
ret_from_fork+0x3a/0x50 arch/x86/entry/entry_64.S:352
Sending NMI from CPU 1 to CPUs 0: