rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3560/1:b..l (detected by 1, t=10502 jiffies, g=8133, q=351) task:udevd state:R running task stack:23264 pid: 3560 ppid: 1 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 preempt_schedule_irq+0xb1/0x150 kernel/sched/core.c:6799 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:seqcount_lockdep_reader_access+0x17a/0x1c0 include/linux/seqlock.h:106 Code: ff 4d 85 ed 75 16 e8 65 48 ad ff eb 15 e8 5e 48 ad ff e8 99 63 d7 07 4d 85 ed 74 ea e8 4f 48 ad ff fb 48 c7 04 24 0e 36 e0 45 <4b> c7 04 27 00 00 00 00 66 43 c7 44 27 09 00 00 43 c6 44 27 0b 00 RSP: 0018:ffffc900012df700 EFLAGS: 00000293 RAX: ffffffff81ca83c1 RBX: 0000000000000000 RCX: ffff88807cfb0000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000000 RBP: ffffc900012df7b0 R08: dffffc0000000000 R09: fffffbfff1ad26b6 R10: fffffbfff1ad26b6 R11: 1ffffffff1ad26b5 R12: dffffc0000000000 R13: 0000000000000200 R14: ffffffff81ca9232 R15: 1ffff9200025bee0 __follow_mount_rcu fs/namei.c:1465 [inline] handle_mounts fs/namei.c:1498 [inline] step_into+0x642/0xd00 fs/namei.c:1814 link_path_walk+0x662/0xd40 fs/namei.c:-1 path_lookupat+0x9d/0x440 fs/namei.c:2462 filename_lookup+0x1e2/0x4f0 fs/namei.c:2492 user_path_at_empty+0x40/0x190 fs/namei.c:2891 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: 0033:0x7f595f588b0a RSP: 002b:00007ffeb4c83798 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 00007ffeb4c83c30 RCX: 00007f595f588b0a RDX: 00007ffeb4c837a0 RSI: 00007ffeb4c83c30 RDI: 00000000ffffff9c RBP: 000055a15a107910 R08: 0000000000000000 R09: 0000000000000001 R10: 0000000000000000 R11: 0000000000000246 R12: 00007ffeb4c83830 R13: 00000000000000fe R14: 000055a141b4abe0 R15: 00007ffeb4c84330 rcu: rcu_preempt kthread starved for 9940 jiffies! g8133 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->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:R running task stack:27880 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5049 [inline] __schedule+0x11bb/0x4390 kernel/sched/core.c:6395 schedule+0x11b/0x1e0 kernel/sched/core.c:6478 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:729