INFO: task khugepaged:1087 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 D27704 1087 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/u4:3/159: #0: ffff8880a746e528 ((wq_completion)writeback){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880a746e528 ((wq_completion)writeback){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a746e528 ((wq_completion)writeback){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880a746e528 ((wq_completion)writeback){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880a746e528 ((wq_completion)writeback){+.+.}, at: set_work_data kernel/workqueue.c:614 [inline] #0: ffff8880a746e528 ((wq_completion)writeback){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:641 [inline] #0: ffff8880a746e528 ((wq_completion)writeback){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2234 #1: ffff8880a953fdc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2238 #2: ffff88809b7b20d8 (&type->s_umount_key#32){++++}, at: trylock_super+0x22/0x110 fs/super.c:418 #3: ffff88809b7b4990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 1 lock held by khungtaskd/1080: #0: ffffffff88faba40 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5336 1 lock held by khugepaged/1087: #0: ffff88809b7b4990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 2 locks held by rsyslogd/8805: #0: ffff8880a3fdd620 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: ffffffff88faba40 (rcu_read_lock){....}, at: syslog_print kernel/printk/printk.c:1364 [inline] #1: ffffffff88faba40 (rcu_read_lock){....}, at: do_syslog kernel/printk/printk.c:1529 [inline] #1: ffffffff88faba40 (rcu_read_lock){....}, at: do_syslog+0x699/0x1870 kernel/printk/printk.c:1503 2 locks held by getty/8895: #0: ffff8880a7399090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f3b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8896: #0: ffff88809c017090 (&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/8897: #0: ffff888097075090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f4b2e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8898: #0: ffff88809280c090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f472e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8899: #0: ffff88809aec9090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f372e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 2 locks held by getty/8900: #0: ffff8880a7b31090 (&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/8901: #0: ffff8880a8671090 (&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 syz-executor.1/8936: #0: ffff8880601180d8 (&type->s_umount_key#50){+.+.}, at: deactivate_super fs/super.c:365 [inline] #0: ffff8880601180d8 (&type->s_umount_key#50){+.+.}, at: deactivate_super+0x1aa/0x1d0 fs/super.c:362 #1: ffff88809b7b20d8 (&type->s_umount_key#32){++++}, at: ovl_sync_fs+0xb7/0x100 fs/overlayfs/super.c:275 2 locks held by syz-executor.2/8938: #0: ffff88805f02c0d8 (&type->s_umount_key#50){+.+.}, at: deactivate_super fs/super.c:365 [inline] #0: ffff88805f02c0d8 (&type->s_umount_key#50){+.+.}, at: deactivate_super+0x1aa/0x1d0 fs/super.c:362 #1: ffff88809b7b20d8 (&type->s_umount_key#32){++++}, at: ovl_sync_fs+0xb7/0x100 fs/overlayfs/super.c:275 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1080 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: 9004 Comm: kworker/0:5 Not tainted 5.4.0-rc5-next-20191031 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 Workqueue: events_power_efficient gc_worker RIP: 0010:lock_is_held_type+0x220/0x320 kernel/locking/lockdep.c:4525 Code: e0 03 3b 45 cc 41 0f 94 c4 65 48 8b 1c 25 80 fe 01 00 48 8d bb 9c 08 00 00 48 b8 00 00 00 00 00 fc ff df 48 89 fa 48 c1 ea 03 <0f> b6 14 02 48 89 f8 83 e0 07 83 c0 03 38 d0 7c 08 84 d2 0f 85 d3 RSP: 0018:ffff888060037bc0 EFLAGS: 00000803 RAX: dffffc0000000000 RBX: ffff88806002a240 RCX: ffff88806002aae0 RDX: 1ffff1100c00555b RSI: ffffffff88fab9c0 RDI: ffff88806002aadc RBP: ffff888060037c08 R08: 0000000000000003 R09: ffff88806002aad8 R10: fffffbfff1390778 R11: ffffffff89c83bc7 R12: 0000000000000000 R13: ffff88806002ab08 R14: ffffffff88fab9c0 R15: 0000000000000002 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: ffffffffff600400 CR3: 00000000956a5000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: lock_is_held include/linux/lockdep.h:361 [inline] ___might_sleep+0x205/0x2c0 kernel/sched/core.c:6753 gc_worker+0x759/0xdd0 net/netfilter/nf_conntrack_core.c:1294 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