rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-...!: (1803 ticks this GP) idle=826/1/0x4000000000000000 softirq=47766/47766 fqs=2 (t=10502 jiffies g=69697 q=136) rcu: rcu_preempt kthread starved for 10301 jiffies! g69697 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:29176 pid: 11 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3779 [inline] __schedule+0x893/0x2130 kernel/sched/core.c:4528 schedule+0xcf/0x270 kernel/sched/core.c:4606 schedule_timeout+0x148/0x250 kernel/time/timer.c:1871 rcu_gp_fqs_loop kernel/rcu/tree.c:1925 [inline] rcu_gp_kthread+0xb4c/0x1c90 kernel/rcu/tree.c:2099 kthread+0x3b1/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:296 NMI backtrace for cpu 1 CPU: 1 PID: 22306 Comm: syz-executor.1 Not tainted 5.10.0-syzkaller #0 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+0x107/0x163 lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x44/0xd7 lib/nmi_backtrace.c:105 nmi_trigger_cpumask_backtrace+0x1b3/0x230 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x1e3/0x21e kernel/rcu/tree_stall.h:331 print_cpu_stall kernel/rcu/tree_stall.h:563 [inline] check_cpu_stall kernel/rcu/tree_stall.h:637 [inline] rcu_pending kernel/rcu/tree.c:3694 [inline] rcu_sched_clock_irq.cold+0x472/0xee8 kernel/rcu/tree.c:2567 update_process_times+0x77/0xd0 kernel/time/timer.c:1709 tick_sched_handle+0x9b/0x180 kernel/time/tick-sched.c:176 tick_sched_timer+0x1d1/0x2a0 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1519 [inline] __hrtimer_run_queues+0x1ce/0xea0 kernel/time/hrtimer.c:1583 hrtimer_interrupt+0x334/0x940 kernel/time/hrtimer.c:1645 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x146/0x540 arch/x86/kernel/apic/apic.c:1097 run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:91 [inline] sysvec_apic_timer_interrupt+0x48/0x100 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x25/0x40 kernel/locking/spinlock.c:199 Code: 0f 1f 44 00 00 55 48 8b 74 24 08 48 89 fd 48 83 c7 18 e8 3e 59 6e f8 48 89 ef e8 c6 0d 6f f8 e8 41 f7 8d f8 fb bf 01 00 00 00 86 79 63 f8 65 8b 05 cf 23 1a 77 85 c0 74 02 5d c3 e8 3b 79 18 RSP: 0018:ffffc90000d90e18 EFLAGS: 00000212 RAX: 0000000001295cb0 RBX: ffffffff87c88dc0 RCX: ffffffff8155a947 RDX: 0000000000000000 RSI: 0000000000000102 RDI: 0000000000000001 RBP: ffff8880b9f24780 R08: 0000000000000001 R09: ffffffff8ebb0717 R10: fffffbfff1d760e2 R11: 0000000000000001 R12: ffffc90000d90ea8 R13: 0000000000000000 R14: dffffc0000000000 R15: ffff8880b9f24780 expire_timers kernel/time/timer.c:1454 [inline] __run_timers.part.0+0x66c/0xa50 kernel/time/timer.c:1747 __run_timers kernel/time/timer.c:1728 [inline] run_timer_softirq+0xb3/0x1d0 kernel/time/timer.c:1760 __do_softirq+0x2a0/0x9f6 kernel/softirq.c:298 asm_call_irq_on_stack+0xf/0x20 __run_on_irqstack arch/x86/include/asm/irq_stack.h:26 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:77 [inline] do_softirq_own_stack+0xaa/0xd0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu kernel/softirq.c:423 [inline] irq_exit_rcu+0x132/0x200 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x4d/0x100 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:631 RIP: 0010:match_futex kernel/futex.c:382 [inline] RIP: 0010:futex_wake+0x2a8/0x490 kernel/futex.c:1608 Code: 8b 75 40 4c 8b 7c 24 70 4c 89 f7 4c 89 fe e8 1f c7 0b 00 4d 39 fe 75 86 e8 25 cf 0b 00 48 8b 04 24 48 c1 e8 03 42 80 3c 20 00 <0f> 85 a2 01 00 00 48 8b 45 38 4c 8b 74 24 68 48 89 c7 48 89 04 24 RSP: 0018:ffffc900023afb58 EFLAGS: 00000246 RAX: 1ffff9200046bf75 RBX: ffffc90000df7c30 RCX: ffffc9000c71a000 RDX: 0000000000040000 RSI: ffffffff8164357b RDI: 0000000000000006 RBP: ffffc9000235fb70 R08: 0000000000000001 R09: 0000000000000003 R10: 000000000119b000 R11: 0000000000000000 R12: dffffc0000000000 R13: 0000000000000000 R14: 000000000119b000 R15: 000000000119b000 do_futex+0x322/0x1a60 kernel/futex.c:3770 __do_sys_futex+0x2a2/0x470 kernel/futex.c:3828 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45e159 Code: 0d b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 00 66 90 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 0f 83 db b3 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007fad5499dcf8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: ffffffffffffffda RBX: 000000000119bf88 RCX: 000000000045e159 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 000000000119bf8c RBP: 000000000119bf80 R08: 000000000000000e R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 000000000119bf8c R13: 00007ffcaa856a9f R14: 00007fad5499e9c0 R15: 000000000119bf8c