rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P8400 (detected by 1, t=10503 jiffies, g=6813, q=219) udevd R running task 27864 8400 4086 0x0000400a Call Trace: sched_show_task+0x40f/0x560 kernel/sched/core.c:5954 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:190 [inline] print_other_cpu_stall kernel/rcu/tree_stall.h:398 [inline] check_cpu_stall kernel/rcu/tree_stall.h:538 [inline] rcu_pending kernel/rcu/tree.c:2827 [inline] rcu_sched_clock_irq+0x16b1/0x1ad0 kernel/rcu/tree.c:2271 update_process_times+0x12d/0x180 kernel/time/timer.c:1726 tick_sched_handle kernel/time/tick-sched.c:167 [inline] tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310 __run_hrtimer kernel/time/hrtimer.c:1517 [inline] __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1579 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1641 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline] smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829 RIP: 0010:mod_memcg_page_state+0xb/0x190 include/linux/memcontrol.h:652 Code: 8b 26 2e 00 eb 05 e8 84 26 2e 00 48 83 c4 10 5b 41 5c 41 5d 41 5e 41 5f 5d c3 0f 1f 44 00 00 55 48 89 e5 41 57 41 56 41 54 53 <41> 89 f6 48 89 fb e8 5a 26 2e 00 48 83 c3 38 48 89 d8 48 c1 e8 03 RSP: 0018:ffffc90002017928 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13 RAX: 1ffff1100d85d101 RBX: ffff88806c2e8808 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea0002426e00 RBP: ffffc90002017948 R08: 000000000003a728 R09: ffffed1014e6ee9f R10: ffffed1014e6ee9f R11: 0000000000000000 R12: ffff88806c2e88a0 R13: dffffc0000000000 R14: 1ffff1100d85d114 R15: ffff8880a73774e8 free_thread_stack+0x168/0x590 kernel/fork.c:280 release_task_stack kernel/fork.c:440 [inline] put_task_stack+0xa3/0x130 kernel/fork.c:451 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256 context_switch kernel/sched/core.c:3388 [inline] __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081 preempt_schedule_common kernel/sched/core.c:4236 [inline] preempt_schedule+0xdb/0x120 kernel/sched/core.c:4261 ___preempt_schedule+0x16/0x18 arch/x86/entry/thunk_64.S:50 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0xcc/0xe0 kernel/locking/spinlock.c:191 spin_unlock_irqrestore include/linux/spinlock.h:393 [inline] __wake_up_common_lock kernel/sched/wait.c:125 [inline] __wake_up_sync_key+0xe2/0x150 kernel/sched/wait.c:190 sock_def_readable+0x162/0x200 net/core/sock.c:2796 unix_dgram_sendmsg+0x1bd5/0x2690 net/unix/af_unix.c:1762 sock_sendmsg_nosec net/socket.c:639 [inline] sock_sendmsg net/socket.c:659 [inline] __sys_sendto+0x442/0x5e0 net/socket.c:1985 __do_sys_sendto net/socket.c:1997 [inline] __se_sys_sendto net/socket.c:1993 [inline] __x64_sys_sendto+0xe5/0x100 net/socket.c:1993 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294 entry_SYSCALL_64_after_hwframe+0x49/0xbe RIP: 0033:0x7f38509b9282 Code: 48 83 c8 ff eb ea 90 90 53 48 83 ec 20 8b 05 81 d3 2a 00 85 c0 75 21 45 31 c9 45 31 c0 4c 63 d1 48 63 ff b8 2c 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 61 48 83 c4 20 5b c3 48 89 54 24 08 89 0c 24 RSP: 002b:00007ffcd8ff06b0 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 0000000000f5ed20 RCX: 00007f38509b9282 RDX: 0000000000000008 RSI: 00007ffcd8ff0700 RDI: 0000000000000009 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000f5f1a0 R14: 0000000000f5c250 R15: 000000000000000b rcu: rcu_preempt kthread starved for 10537 jiffies! g6813 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=1 rcu: RCU grace-period kthread stack dump: rcu_preempt I29032 10 2 0x80004000 Call Trace: context_switch kernel/sched/core.c:3385 [inline] __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081 schedule+0x181/0x210 kernel/sched/core.c:4155 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline] rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821 kthread+0x332/0x350 kernel/kthread.c:255 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352