INFO: task kworker/u4:0:7 blocked for more than 143 seconds. Not tainted 5.4.0-rc4-next-20191025 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. kworker/u4:0 D24344 7 2 0x80004000 Workqueue: writeback wb_workfn (flush-8:0) 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 do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 __writeback_single_inode+0x136/0x1400 fs/fs-writeback.c:1449 writeback_sb_inodes+0x596/0xf20 fs/fs-writeback.c:1713 __writeback_inodes_wb+0xc3/0x260 fs/fs-writeback.c:1782 wb_writeback+0x910/0xd90 fs/fs-writeback.c:1891 wb_check_old_data_flush fs/fs-writeback.c:1993 [inline] wb_do_writeback fs/fs-writeback.c:2046 [inline] wb_workfn+0xba5/0x1220 fs/fs-writeback.c:2075 process_one_work+0x9af/0x1740 kernel/workqueue.c:2269 worker_thread+0x98/0xe40 kernel/workqueue.c:2415 kthread+0x361/0x430 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352 INFO: task khugepaged:1088 blocked for more than 143 seconds. Not tainted 5.4.0-rc4-next-20191025 #0 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. khugepaged D27488 1088 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+0xb6a/0x2e70 fs/ext4/inode.c:2866 ? 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/u4:0/7: #0: ffff8880a7876128 ((wq_completion)writeback){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880a7876128 ((wq_completion)writeback){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a7876128 ((wq_completion)writeback){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880a7876128 ((wq_completion)writeback){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880a7876128 ((wq_completion)writeback){+.+.}, at: set_work_data kernel/workqueue.c:620 [inline] #0: ffff8880a7876128 ((wq_completion)writeback){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:647 [inline] #0: ffff8880a7876128 ((wq_completion)writeback){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2240 #1: ffff8880a988fdc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2244 #2: ffff8882155700d8 (&type->s_umount_key#32){++++}, at: trylock_super+0x22/0x110 fs/super.c:418 #3: ffff888215572990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 1 lock held by khungtaskd/803: #0: ffffffff88faba80 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5336 1 lock held by khugepaged/1088: #0: ffff888215572990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 1 lock held by rsyslogd/8570: #0: ffff8880a76081a0 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8660: #0: ffff8880a7ec2090 (&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/8661: #0: ffff8880996ee090 (&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/8662: #0: ffff8880a287d090 (&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/8663: #0: ffff88809f47e090 (&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/8664: #0: ffff8880a8fc5090 (&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/8665: #0: ffff8880a1d6c090 (&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/8666: #0: ffff8880994eb090 (&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 1 lock held by syz-execprog/8693: #0: ffff8880906a03a8 (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7e/0xb2 fs/ext4/inode.c:6291 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 803 Comm: khungtaskd Not tainted 5.4.0-rc4-next-20191025 #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: 0 Comm: swapper/0 Not tainted 5.4.0-rc4-next-20191025 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:__lock_release kernel/locking/lockdep.c:4228 [inline] RIP: 0010:lock_release+0x218/0x960 kernel/locking/lockdep.c:4505 Code: 8b 35 50 cc 6e 08 85 f6 0f 84 47 02 00 00 4d 8d 8f 98 08 00 00 48 b8 00 00 00 00 00 fc ff df 4c 89 ca 48 c1 ea 03 0f b6 04 02 <84> c0 74 08 3c 03 0f 8e 22 06 00 00 45 8b 87 98 08 00 00 45 85 c0 RSP: 0018:ffff8880ae809e28 EFLAGS: 00000806 RAX: 0000000000000000 RBX: 1ffff11015d013ca RCX: 1ffffffff1390b56 RDX: 1ffffffff11cf54b RSI: 0000000000000001 RDI: ffffffff88e7aa5c RBP: ffff8880ae809ef8 R08: 1ffffffff1390518 R09: ffffffff88e7aa58 R10: fffffbfff1390518 R11: ffffffff89c828c7 R12: ffffffff88fbaa08 R13: ffffffff81675fd5 R14: ffff8880ae809ed0 R15: ffffffff88e7a1c0 FS: 0000000000000000(0000) GS:ffff8880ae800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000000002609000 CR3: 00000000a0933000 CR4: 00000000001406f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: seqcount_lockdep_reader_access include/linux/seqlock.h:82 [inline] read_seqcount_begin include/linux/seqlock.h:164 [inline] ktime_get kernel/time/timekeeping.c:757 [inline] ktime_get+0xe2/0x2f0 kernel/time/timekeeping.c:747 tick_nohz_irq_enter kernel/time/tick-sched.c:1253 [inline] tick_irq_enter+0xb5/0x3f0 kernel/time/tick-sched.c:1274 irq_enter+0xbd/0xe0 kernel/softirq.c:354 entering_irq arch/x86/include/asm/apic.h:517 [inline] entering_ack_irq arch/x86/include/asm/apic.h:523 [inline] smp_apic_timer_interrupt+0x3f/0x610 arch/x86/kernel/apic/apic.c:1133 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:native_safe_halt+0xe/0x10 arch/x86/include/asm/irqflags.h:61 Code: a8 f4 59 fa eb 8a 90 90 90 90 90 90 e9 07 00 00 00 0f 00 2d 04 06 53 00 f4 c3 66 90 e9 07 00 00 00 0f 00 2d f4 05 53 00 fb f4 90 55 48 89 e5 41 57 41 56 41 55 41 54 53 e8 3e d4 0b fa e8 79 RSP: 0018:ffffffff88e07ce8 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13 RAX: 1ffffffff11e643f RBX: ffffffff88e7a1c0 RCX: 0000000000000000 RDX: dffffc0000000000 RSI: 0000000000000006 RDI: ffffffff88e7aa5c RBP: ffffffff88e07d18 R08: ffffffff88e7a1c0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: dffffc0000000000 R13: ffffffff89c828c0 R14: 0000000000000000 R15: 0000000000000000 arch_cpu_idle+0xa/0x10 arch/x86/kernel/process.c:571 default_idle_call+0x84/0xb0 kernel/sched/idle.c:94 cpuidle_idle_call kernel/sched/idle.c:154 [inline] do_idle+0x3b7/0x6e0 kernel/sched/idle.c:263 cpu_startup_entry+0x1b/0x20 kernel/sched/idle.c:355 rest_init+0x23b/0x371 init/main.c:451 arch_call_rest_init+0xe/0x1b start_kernel+0x904/0x943 init/main.c:784 x86_64_start_reservations+0x29/0x2b arch/x86/kernel/head64.c:490 x86_64_start_kernel+0x77/0x7b arch/x86/kernel/head64.c:471 secondary_startup_64+0xa4/0xb0 arch/x86/kernel/head_64.S:242