rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 0-....: (1 GPs behind) idle=dea/1/0x4000000000000000 softirq=240641/240642 fqs=2743 (t=10500 jiffies g=446721 q=1670) rcu: rcu_preempt kthread starved for 4227 jiffies! g446721 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:28896 pid: 10 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x979/0xce0 kernel/sched/core.c:4527 NMI backtrace for cpu 0 CPU: 0 PID: 28233 Comm: syz-executor.5 Not tainted 5.9.0-rc1-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+0x1f0/0x31e lib/dump_stack.c:118 nmi_cpu_backtrace+0x9f/0x180 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x16a/0x280 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x199/0x2a0 kernel/rcu/tree_stall.h:318 print_cpu_stall kernel/rcu/tree_stall.h:551 [inline] check_cpu_stall kernel/rcu/tree_stall.h:625 [inline] rcu_pending kernel/rcu/tree.c:3637 [inline] rcu_sched_clock_irq+0x1920/0x1eb0 kernel/rcu/tree.c:2519 update_process_times+0x130/0x1b0 kernel/time/timer.c:1710 tick_sched_handle kernel/time/tick-sched.c:176 [inline] tick_sched_timer+0x25e/0x410 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x42d/0x930 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x373/0xd60 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0xf0/0x260 arch/x86/kernel/apic/apic.c:1097 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] sysvec_apic_timer_interrupt+0xd0/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:lock_acquire+0x1c7/0x730 kernel/locking/lockdep.c:5008 Code: c1 e8 03 80 3c 10 00 74 0c 48 c7 c7 f8 14 4d 89 e8 9e e9 5a 00 48 83 3d 3e 2d f3 07 00 0f 84 08 05 00 00 48 8b 7c 24 10 57 9d <0f> 1f 44 00 00 65 48 8b 04 25 28 00 00 00 48 3b 44 24 50 0f 85 df RSP: 0018:ffffc90000007cf0 EFLAGS: 00000286 RAX: 1ffffffff129a29f RBX: 0000000000000000 RCX: ffffffff815acaa4 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000286 RBP: ffff888018d0ece4 R08: dffffc0000000000 R09: fffffbfff167d6b2 R10: fffffbfff167d6b2 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffff110031a1d9c R15: 0000000000000000 __raw_spin_lock include/linux/spinlock_api_smp.h:142 [inline] _raw_spin_lock+0x2a/0x40 kernel/locking/spinlock.c:151 spin_lock include/linux/spinlock.h:354 [inline] mrp_join_timer+0x1e/0x130 net/802/mrp.c:590 call_timer_fn+0x91/0x160 kernel/time/timer.c:1413 expire_timers kernel/time/timer.c:1458 [inline] __run_timers+0x65e/0x830 kernel/time/timer.c:1755 run_timer_softirq+0x46/0x80 kernel/time/timer.c:1768 __do_softirq+0x236/0x66c kernel/softirq.c:298 asm_call_on_stack+0xf/0x20 arch/x86/entry/entry_64.S:706 __run_on_irqstack arch/x86/include/asm/irq_stack.h:22 [inline] run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:48 [inline] do_softirq_own_stack+0x91/0xe0 arch/x86/kernel/irq_64.c:77 invoke_softirq kernel/softirq.c:393 [inline] __irq_exit_rcu+0x1e1/0x1f0 kernel/softirq.c:423 irq_exit_rcu+0x5/0x10 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0xd5/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:770 [inline] RIP: 0010:lock_acquire+0x1c7/0x730 kernel/locking/lockdep.c:5008 Code: c1 e8 03 80 3c 10 00 74 0c 48 c7 c7 f8 14 4d 89 e8 9e e9 5a 00 48 83 3d 3e 2d f3 07 00 0f 84 08 05 00 00 48 8b 7c 24 10 57 9d <0f> 1f 44 00 00 65 48 8b 04 25 28 00 00 00 48 3b 44 24 50 0f 85 df RSP: 0018:ffffc9000772fbd0 EFLAGS: 00000286 RAX: 1ffffffff129a29f RBX: 0000000000000000 RCX: ffffffff815acaa4 RDX: dffffc0000000000 RSI: 0000000000000008 RDI: 0000000000000286 RBP: ffff888018d0ece4 R08: dffffc0000000000 R09: fffffbfff167d69c R10: fffffbfff167d69c R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: 1ffff110031a1d9c R15: 0000000000000000 __mutex_lock_common+0x189/0x2fc0 kernel/locking/mutex.c:956 __mutex_lock kernel/locking/mutex.c:1103 [inline] mutex_lock_nested+0x1a/0x20 kernel/locking/mutex.c:1118 __do_sys_perf_event_open kernel/events/core.c:12004 [inline] __se_sys_perf_event_open+0x3876/0x3f60 kernel/events/core.c:11598 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d4d9 Code: 5d 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 2b b4 fb ff c3 66 2e 0f 1f 84 00 00 00 00 RSP: 002b:00007f61678a2c78 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 0000000000024680 RCX: 000000000045d4d9 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000000020000280 RBP: 000000000118cf90 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffd69843e4f R14: 00007f61678a39c0 R15: 000000000118cf4c