rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4370/1:b..l P3622/1:b..l (detected by 0, t=10502 jiffies, g=8725, q=176 ncpus=2) task:udevd state:R running task stack:24776 pid:3622 ppid:1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5243 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6560 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:link_path_walk+0xc49/0xee0 fs/namei.c:2343 Code: c3 eb 66 e8 a9 93 95 ff 41 bd f6 ff ff ff 48 c7 84 24 a0 00 00 00 0e 36 e0 45 48 8b 84 24 80 00 00 00 49 c7 04 04 00 00 00 00 <65> 48 8b 04 25 28 00 00 00 48 3b 84 24 e0 00 00 00 0f 85 78 02 00 RSP: 0018:ffffc900032678e0 EFLAGS: 00000246 RAX: 1ffff9200064cf30 RBX: ffffc90003267be4 RCX: ffff88807ce91dc0 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc90003267a20 R08: ffffffff81f5102e R09: fffff5200064cf62 R10: 0000000000000000 R11: dffffc0000000001 R12: dffffc0000000000 R13: 0000000000000000 R14: 00000000000041ed R15: ffffc90003267b38 path_lookupat+0xa9/0x450 fs/namei.c:2478 filename_lookup+0x251/0x600 fs/namei.c:2508 vfs_statx+0x10c/0x480 fs/stat.c:229 vfs_fstatat fs/stat.c:267 [inline] __do_sys_newfstatat fs/stat.c:437 [inline] __se_sys_newfstatat fs/stat.c:431 [inline] __x64_sys_newfstatat+0x151/0x1e0 fs/stat.c:431 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7faecd7765f4 RSP: 002b:00007ffca5d096f8 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000055e819a386e0 RCX: 00007faecd7765f4 RDX: 00007ffca5d09708 RSI: 000055e819a28897 RDI: 00000000ffffff9c RBP: 000055e85595da48 R08: 00062305ed946d00 R09: 0000000000000010 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00062305ed946d00 R15: 000055e819a2cdca task:kworker/u4:13 state:R running task stack:24064 pid:4370 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5243 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6560 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6872 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:691 RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666 Code: 2b 00 74 08 4c 89 f7 e8 4f 55 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc90004977a80 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200092ef5c RCX: 1ffff9200092eefc RDX: dffffc0000000000 RSI: ffffffff8b0c2ec0 RDI: ffffffff8b5f6f80 RBP: ffffc90004977be0 R08: dffffc0000000000 R09: fffffbfff225724d R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200092ef58 R13: dffffc0000000000 R14: ffffc90004977ae0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:408 [inline] batadv_nc_worker+0xe8/0x610 net/batman-adv/network-coding.c:719 process_one_work+0x917/0x1260 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 9997 jiffies! g8725 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:R running task stack:26200 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5243 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6560 schedule+0xbf/0x180 kernel/sched/core.c:6636 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:111 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:567 sched: RT throttling activated