INFO: task khugepaged:1050 blocked for more than 143 seconds. Not tainted 5.1.0-rc7+ #99 "echo 0 > /proc/sys/kernel/hung_task_timeout_secs" disables this message. khugepaged D25624 1050 2 0x80000000 Call Trace: context_switch kernel/sched/core.c:2877 [inline] __schedule+0x813/0x1cc0 kernel/sched/core.c:3518 schedule+0x92/0x180 kernel/sched/core.c:3562 __rwsem_down_write_failed_common kernel/locking/rwsem-xadd.c:582 [inline] rwsem_down_write_failed+0x774/0xc30 kernel/locking/rwsem-xadd.c:611 call_rwsem_down_write_failed+0x17/0x30 arch/x86/lib/rwsem.S:117 __down_write arch/x86/include/asm/rwsem.h:142 [inline] down_write+0x53/0x90 kernel/locking/rwsem.c:72 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: 1 lock held by khungtaskd/1043: #0: 000000006ce80a29 (rcu_read_lock){....}, at: debug_show_all_locks+0x5f/0x27e kernel/locking/lockdep.c:5057 1 lock held by khugepaged/1050: #0: 00000000beb76ffc (&mm->mmap_sem){++++}, at: collapse_huge_page+0x22b/0x3f60 mm/khugepaged.c:1006 2 locks held by rs:main Q:Reg/7939: #0: 00000000d5044474 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 #1: 0000000084bd5ce6 (sb_writers#3){.+.+}, at: file_start_write include/linux/fs.h:2825 [inline] #1: 0000000084bd5ce6 (sb_writers#3){.+.+}, at: vfs_write+0x429/0x580 fs/read_write.c:548 1 lock held by rsyslogd/7941: #0: 00000000dfad5b50 (&f->f_pos_lock){+.+.}, at: __fdget_pos+0xee/0x110 fs/file.c:801 2 locks held by getty/8031: #0: 000000002fe5131e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000556b7509 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8032: #0: 00000000fc37555c (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 000000004181d097 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8033: #0: 00000000dafa41a7 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000049f62f1a (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8034: #0: 000000002fe3e572 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000013fdedae (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8035: #0: 0000000043b5fa1e (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000eab741e5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8036: #0: 00000000711deee4 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000b8f467fd (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 2 locks held by getty/8037: #0: 00000000e04db576 (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 0000000081e97b7e (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 1 lock held by syz-fuzzer/8050: 1 lock held by syz-fuzzer/8051: #0: 00000000beb76ffc (&mm->mmap_sem){++++}, at: __do_sys_madvise mm/madvise.c:838 [inline] #0: 00000000beb76ffc (&mm->mmap_sem){++++}, at: __se_sys_madvise mm/madvise.c:802 [inline] #0: 00000000beb76ffc (&mm->mmap_sem){++++}, at: __x64_sys_madvise+0x2bb/0x15f0 mm/madvise.c:802 1 lock held by syz-fuzzer/8053: 2 locks held by kworker/u4:4/30478: #0: 000000000f2a51cb (&rq->lock){-.-.}, at: rq_lock kernel/sched/sched.h:1168 [inline] #0: 000000000f2a51cb (&rq->lock){-.-.}, at: __schedule+0x1f8/0x1cc0 kernel/sched/core.c:3456 #1: 000000006ce80a29 (rcu_read_lock){....}, at: trace_sched_stat_runtime include/trace/events/sched.h:428 [inline] #1: 000000006ce80a29 (rcu_read_lock){....}, at: update_curr+0x2ce/0x8a0 kernel/sched/fair.c:842 2 locks held by syz-executor.1/951: #0: 0000000096f158ca (&tty->ldisc_sem){++++}, at: ldsem_down_read+0x33/0x40 drivers/tty/tty_ldsem.c:341 #1: 00000000a6bd47e5 (&ldata->atomic_read_lock){+.+.}, at: n_tty_read+0x232/0x1b70 drivers/tty/n_tty.c:2156 ============================================= NMI backtrace for cpu 1 CPU: 1 PID: 1043 Comm: khungtaskd Not tainted 5.1.0-rc7+ #99 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: