INFO: task khugepaged:1086 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 1086 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/u4:3/242: #0: ffff8880a7cfe928 ((wq_completion)writeback){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880a7cfe928 ((wq_completion)writeback){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a7cfe928 ((wq_completion)writeback){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880a7cfe928 ((wq_completion)writeback){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880a7cfe928 ((wq_completion)writeback){+.+.}, at: set_work_data kernel/workqueue.c:614 [inline] #0: ffff8880a7cfe928 ((wq_completion)writeback){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:641 [inline] #0: ffff8880a7cfe928 ((wq_completion)writeback){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2234 #1: ffff8880a9307dc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2238 #2: ffff88809ac1a0d8 (&type->s_umount_key#32){++++}, at: trylock_super+0x22/0x110 fs/super.c:418 #3: ffff88809ac1c990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 1 lock held by khungtaskd/1073: #0: ffffffff88faba40 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5336 1 lock held by khugepaged/1086: #0: ffff88809ac1c990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 2 locks held by rs:main Q:Reg/8549: #0: ffff8880ae934d58 (&rq->lock){-.-.}, at: newidle_balance+0xa28/0xe80 kernel/sched/fair.c:10020 #1: ffffffff88faba40 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:435 [inline] #1: ffffffff88faba40 (rcu_read_lock){....}, at: update_curr+0x2ea/0x8d0 kernel/sched/fair.c:860 1 lock held by rsyslogd/8551: #0: ffff8880997506a0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8641: #0: ffff8880a05cd090 (&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/8642: #0: ffff8880a296a090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f152e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8643: #0: ffff8880a747c090 (&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/8644: #0: ffff8880a70b1090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f392e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8645: #0: ffff888098997090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f192e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8646: #0: ffff8880a0b55090 (&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 2 locks held by getty/8647: #0: ffff8880a16cc090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f012e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 1 lock held by syz-executor.5/9396: #0: ffff88809ac1a0d8 (&type->s_umount_key#32){++++}, at: do_remount fs/namespace.c:2550 [inline] #0: ffff88809ac1a0d8 (&type->s_umount_key#32){++++}, at: do_mount+0xec2/0x1b50 fs/namespace.c:3133 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1073 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 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 7 Comm: kworker/u4:0 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:find_held_lock+0x6/0x130 kernel/locking/lockdep.c:4055 Code: e9 91 fc ff ff 4c 89 f7 48 89 75 d0 e8 13 77 56 00 48 8b 75 d0 e9 08 fd ff ff 66 2e 0f 1f 84 00 00 00 00 00 55 48 89 e5 41 57 <44> 8d 7a ff 41 56 49 89 f6 49 63 c7 41 55 48 8d 04 80 41 54 4c 8d RSP: 0018:ffff8880a988fbe8 EFLAGS: 00000006 RAX: 0000000000000000 RBX: 1ffff11015311f85 RCX: ffff8880a988fc68 RDX: 0000000000000003 RSI: ffffffff88faba40 RDI: ffff8880a98801c0 RBP: ffff8880a988fbf0 R08: 0000000000000003 R09: ffff8880a9880a58 R10: fffffbfff1390778 R11: ffffffff89c83bc7 R12: ffffffff88faba40 R13: ffffffff873b88ca R14: ffff8880a988fca8 R15: ffff8880a98801c0 FS: 0000000000000000(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3a0bd05000 CR3: 00000000a77e4000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_release kernel/locking/lockdep.c:4242 [inline] lock_release+0x254/0x960 kernel/locking/lockdep.c:4505 rcu_lock_release include/linux/rcupdate.h:213 [inline] rcu_read_unlock include/linux/rcupdate.h:671 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:411 [inline] batadv_nc_worker+0x220/0x760 net/batman-adv/network-coding.c:718 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