rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3548/1:b..l (detected by 1, t=10502 jiffies, g=9293, q=277) task:udevd state:R running task stack:25056 pid: 3548 ppid: 1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6780 irqentry_exit+0x63/0x70 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x1f2/0x3f0 kernel/locking/lockdep.c:5627 Code: 00 9c 8f 84 24 80 00 00 00 f6 84 24 81 00 00 00 02 0f 85 f6 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 48 c7 44 24 60 0e 36 e0 45 <4b> c7 44 3d 00 00 00 00 00 66 43 c7 44 3d 09 00 00 43 c6 44 3d 0b RSP: 0018:ffffc900021d75c0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 996f1d47a51e6000 RDX: 0000000000000000 RSI: ffffffff8a0b2260 RDI: ffffffff8a59a2c0 RBP: ffffc900021d76e0 R08: dffffc0000000000 R09: fffffbfff1ff3219 R10: fffffbfff1ff3219 R11: 1ffffffff1ff3218 R12: ffffffff8c11be60 R13: 1ffff9200043aec4 R14: 0000000000000246 R15: dffffc0000000000 rcu_lock_acquire+0x2a/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] __d_lookup+0x7c/0x760 fs/dcache.c:2428 lookup_fast+0xd7/0x710 fs/namei.c:1621 walk_component+0x81/0x460 fs/namei.c:1972 link_path_walk+0x662/0xd40 fs/namei.c:-1 path_lookupat+0x9d/0x440 fs/namei.c:2454 filename_lookup+0x1e2/0x4f0 fs/namei.c:2484 user_path_at_empty+0x40/0x190 fs/namei.c:2883 user_path_at include/linux/namei.h:57 [inline] vfs_statx+0x102/0x4d0 fs/stat.c:221 vfs_fstatat fs/stat.c:243 [inline] __do_sys_newfstatat fs/stat.c:411 [inline] __se_sys_newfstatat fs/stat.c:405 [inline] __x64_sys_newfstatat+0x12c/0x1b0 fs/stat.c:405 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x4c/0xa0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7f2df1bd45f4 RSP: 002b:00007ffd517bd698 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000056516fae0c00 RCX: 00007f2df1bd45f4 RDX: 00007ffd517bd6a8 RSI: 00007ffd517bdb38 RDI: 00000000ffffff9c RBP: 00007ffd517bd738 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffd517bdb38 R13: 00007ffd517bd6a8 R14: 000056516fad9910 R15: 0000000000000000 rcu: rcu_preempt kthread timer wakeup didn't happen for 8594 jiffies! g9293 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=4503 rcu: rcu_preempt kthread starved for 8595 jiffies! g9293 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 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:I stack:27808 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5030 [inline] __schedule+0x11b8/0x43b0 kernel/sched/core.c:6376 schedule+0x11b/0x1e0 kernel/sched/core.c:6459 schedule_timeout+0x15c/0x280 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x29e/0x11b0 kernel/rcu/tree.c:1972 rcu_gp_kthread+0x98/0x350 kernel/rcu/tree.c:2145 kthread+0x436/0x520 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 0 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 0 skipped: idling at default_idle+0xb/0x10 arch/x86/kernel/process.c:722