INFO: task khugepaged:1050 blocked for more than 143 seconds. Not tainted 5.1.0+ #2 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. khugepaged D29008 1050 2 0x80004002 Call Trace: context_switch kernel/sched/core.c:2817 [inline] __schedule+0x7d1/0x1580 kernel/sched/core.c:3444 schedule+0xa8/0x260 kernel/sched/core.c:3508 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:585 [inline] rwsem_down_write_failed+0x7a1/0xc60 kernel/locking/rwsem-xadd.c:617 __down_write kernel/locking/rwsem.h:227 [inline] down_write+0x93/0xa0 kernel/locking/rwsem.c:68 collapse_huge_page+0x22b/0x3f60 mm/khugepaged.c:1006 khugepaged_scan_pmd mm/khugepaged.c:1215 [inline] khugepaged_scan_mm_slot mm/khugepaged.c:1725 [inline] khugepaged_do_scan mm/khugepaged.c:1806 [inline] khugepaged+0x28c3/0x3f40 mm/khugepaged.c:1851 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: 2 locks held by kworker/u4:2/27: #0: 00000000021ee84b (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline] #0: 00000000021ee84b (&rq->lock){-.-.}, at: __schedule+0x1f5/0x1580 kernel/sched/core.c:3396 #1: 00000000775358ce (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline] #1: 00000000775358ce (rcu_read_lock){....}, at: update_curr+0x2ce/0x8a0 kernel/sched/fair.c:842 1 lock held by khungtaskd/1043: #0: 00000000775358ce (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5148 1 lock held by khugepaged/1050: #0: 00000000d783b550 (&mm->mmap_sem#2){++++}, at: collapse_huge_page+0x22b/0x3f60 mm/khugepaged.c:1006 2 locks held by rs:main Q:Reg/7620: #0: 00000000037ccb31 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: 0000000031fda072 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2825 [inline] #1: 0000000031fda072 (sb_writers#3){.+.+}, at: vfs_write+0x429/0x580 fs/read_write.c:548 1 lock held by rsyslogd/7622: #0: 000000003982f90b (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/7712: #0: 000000001259c200 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b685ff57 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7713: #0: 000000008d6cdd62 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000001ab375ad (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7714: #0: 00000000468246cf (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000306de473 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7715: #0: 00000000e3e88028 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000aa7c396c (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7716: #0: 00000000fdf9b841 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000002f5ab3fc (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7717: #0: 000000005b261b3b (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000002574170e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/7718: #0: 00000000104d4dc9 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000bc0bc82b (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-fuzzer/7734: #0: 00000000d783b550 (&mm->mmap_sem#2){++++}, at: __do_sys_madvise mm/madvise.c:838 [inline] #0: 00000000d783b550 (&mm->mmap_sem#2){++++}, at: __se_sys_madvise mm/madvise.c:802 [inline] #0: 00000000d783b550 (&mm->mmap_sem#2){++++}, at: __x64_sys_madvise+0x2bb/0x15f0 mm/madvise.c:802 1 lock held by syz-fuzzer/7737: 1 lock held by syz-executor.3/14717: #0: 00000000d9fa00ae (&type->s_umount_key#30){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:721 2 locks held by syz-executor.3/14739: #0: 00000000d9fa00ae (&type->s_umount_key#30){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:721 #1: 00000000021ee84b (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline] #1: 00000000021ee84b (&rq->lock){-.-.}, at: __schedule+0x1f5/0x1580 kernel/sched/core.c:3396 1 lock held by syz-executor.5/14782: #0: 00000000696eb4da (&bdev->bd_mutex){+.+.}, at: iterate_bdevs+0xca/0x294 fs/block_dev.c:2216 2 locks held by syz-executor.3/14812: #0: 00000000d9fa00ae (&type->s_umount_key#30){++++}, at: iterate_supers+0xe2/0x290 fs/super.c:721 #1: 00000000021ee84b (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline] #1: 00000000021ee84b (&rq->lock){-.-.}, at: __schedule+0x1f5/0x1580 kernel/sched/core.c:3396 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1043 Comm: khungtaskd Not tainted 5.1.0+ #2 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: