INFO: task kworker/u4:1:21 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. kworker/u4:1 D24344 21 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: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 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 D27704 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+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/u4:1/21: #0: ffff8880a7e4e128 ((wq_completion)writeback){+.+.}, at: __write_once_size include/linux/compiler.h:226 [inline] #0: ffff8880a7e4e128 ((wq_completion)writeback){+.+.}, at: arch_atomic64_set arch/x86/include/asm/atomic64_64.h:34 [inline] #0: ffff8880a7e4e128 ((wq_completion)writeback){+.+.}, at: atomic64_set include/asm-generic/atomic-instrumented.h:855 [inline] #0: ffff8880a7e4e128 ((wq_completion)writeback){+.+.}, at: atomic_long_set include/asm-generic/atomic-long.h:40 [inline] #0: ffff8880a7e4e128 ((wq_completion)writeback){+.+.}, at: set_work_data kernel/workqueue.c:614 [inline] #0: ffff8880a7e4e128 ((wq_completion)writeback){+.+.}, at: set_work_pool_and_clear_pending kernel/workqueue.c:641 [inline] #0: ffff8880a7e4e128 ((wq_completion)writeback){+.+.}, at: process_one_work+0x88b/0x1740 kernel/workqueue.c:2234 #1: ffff8880a9a07dc0 ((work_completion)(&(&wb->dwork)->work)){+.+.}, at: process_one_work+0x8c1/0x1740 kernel/workqueue.c:2238 #2: ffff88809b21e0d8 (&type->s_umount_key#32){++++}, at: trylock_super+0x22/0x110 fs/super.c:418 #3: ffff88809b220990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 1 lock held by khungtaskd/1077: #0: ffffffff88faba40 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x279 kernel/locking/lockdep.c:5336 1 lock held by khugepaged/1086: #0: ffff88809b220990 (&sbi->s_journal_flag_rwsem){.+.+}, at: do_writepages+0xfa/0x2a0 mm/page-writeback.c:2344 2 locks held by getty/8582: #0: ffff888097fb4090 (&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/8583: #0: ffff8880a8f15090 (&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/8584: #0: ffff888096948090 (&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/8585: #0: ffff88809258e090 (&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/8586: #0: ffff88809c461090 (&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/8587: #0: ffff88809309a090 (&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/8588: #0: ffff8880a79f0090 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:340 #1: ffffc90005f092e0 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x220/0x1bf0 drivers/tty/n_tty.c:2156 1 lock held by syz-execprog/8613: #0: ffff8880a315f3a8 (&ei->i_mmap_sem){++++}, at: ext4_filemap_fault+0x7e/0xb2 fs/ext4/inode.c:6291 ============================================= NMI backtrace for cpu 0 CPU: 0 PID: 1077 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: 8609 Comm: syz-execprog Not tainted 5.4.0-rc5-next-20191031 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:task_css_set include/linux/cgroup.h:473 [inline] RIP: 0010:task_dfl_cgroup include/linux/cgroup.h:542 [inline] RIP: 0010:cgroup_account_cputime include/linux/cgroup.h:780 [inline] RIP: 0010:update_curr+0x36a/0x8d0 kernel/sched/fair.c:861 Code: ff df 48 89 fa 48 c1 ea 03 80 3c 02 00 0f 85 b8 04 00 00 4c 8b ab 78 10 00 00 e8 a1 bd 0c 00 85 c0 74 0d 80 3d 4b ec 70 08 00 <0f> 84 b4 02 00 00 49 8d 7d 78 48 b8 00 00 00 00 00 fc ff df 48 89 RSP: 0018:ffff8880a8d8f760 EFLAGS: 00000046 RAX: 0000000000000001 RBX: ffff8880962d0500 RCX: 1ffffffff1390a0e RDX: 0000000000000000 RSI: 0000000000000004 RDI: ffff8880962d0d1c RBP: ffff8880a8d8f7a0 R08: 1ffff11015d26b7c R09: ffffed1015d26b7d R10: ffffed1015d26b7c R11: ffff8880ae935be3 R12: ffff8880ae934dc0 R13: ffffffff88fcada0 R14: ffff8880962d0480 R15: 0000000000005f09 FS: 00000000014e2c48(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00000000018d8000 CR3: 0000000099d97000 CR4: 00000000001406e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: dequeue_entity+0x1e/0x1150 kernel/sched/fair.c:4083 dequeue_task_fair+0xad/0x930 kernel/sched/fair.c:5316 dequeue_task kernel/sched/core.c:1315 [inline] deactivate_task+0x114/0x420 kernel/sched/core.c:1335 __schedule+0x11b1/0x1e70 kernel/sched/core.c:4030 schedule+0xdc/0x2b0 kernel/sched/core.c:4144 freezable_schedule include/linux/freezer.h:172 [inline] futex_wait_queue_me+0x2c4/0x590 kernel/futex.c:2627 futex_wait+0x217/0x5d0 kernel/futex.c:2733 do_futex+0x175/0x1de0 kernel/futex.c:3644 __do_sys_futex kernel/futex.c:3705 [inline] __se_sys_futex kernel/futex.c:3673 [inline] __x64_sys_futex+0x3f7/0x590 kernel/futex.c:3673 do_syscall_64+0xfa/0x760 arch/x86/entry/common.c:290 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x459043 Code: cc cc cc cc cc cc cc 48 8b 7c 24 08 8b 74 24 10 8b 54 24 14 4c 8b 54 24 18 4c 8b 44 24 20 44 8b 4c 24 28 b8 ca 00 00 00 0f 05 <89> 44 24 30 c3 cc cc cc cc cc cc cc cc 8b 7c 24 08 48 8b 74 24 10 RSP: 002b:00007fff708e4a78 EFLAGS: 00000206 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 00000000000186a0 RCX: 0000000000459043 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00000000014e22c8 RBP: 00007fff708e4ac0 R08: 0000000000000000 R09: 0000000000000000 R10: 00007fff708e4ab0 R11: 0000000000000206 R12: 00000000000000a0 R13: 00000000000000ff R14: 00007fb889174000 R15: 0000000000000004