rcu: INFO: rcu_preempt self-detected stall on CPU rcu: 1-....: (1 GPs behind) idle=db6/1/0x4000000000000000 softirq=201223/201224 fqs=3377 (t=10500 jiffies g=394697 q=31501) rcu: rcu_preempt kthread starved for 3171 jiffies! g394697 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:28864 pid: 10 ppid: 2 flags:0x10004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x8e5/0x21e0 kernel/sched/core.c:4527 schedule+0xd0/0x2a0 kernel/sched/core.c:4602 schedule_timeout+0x148/0x250 kernel/time/timer.c:1879 rcu_gp_fqs_loop kernel/rcu/tree.c:1888 [inline] rcu_gp_kthread+0xae5/0x1b50 kernel/rcu/tree.c:2058 kthread+0x3b5/0x4a0 kernel/kthread.c:292 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:294 NMI backtrace for cpu 1 CPU: 1 PID: 27602 Comm: syz-executor.3 Not tainted 5.9.0-rc2-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+0x18f/0x20d lib/dump_stack.c:118 nmi_cpu_backtrace.cold+0x70/0xb1 lib/nmi_backtrace.c:101 nmi_trigger_cpumask_backtrace+0x1b3/0x223 lib/nmi_backtrace.c:62 trigger_single_cpu_backtrace include/linux/nmi.h:164 [inline] rcu_dump_cpu_stacks+0x194/0x1cf 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.cold+0x5b3/0xccd kernel/rcu/tree.c:2519 update_process_times+0x25/0xa0 kernel/time/timer.c:1710 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:1524 [inline] __hrtimer_run_queues+0x1d5/0xfc0 kernel/time/hrtimer.c:1588 hrtimer_interrupt+0x32a/0x930 kernel/time/hrtimer.c:1650 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1080 [inline] __sysvec_apic_timer_interrupt+0x142/0x5e0 arch/x86/kernel/apic/apic.c:1097 run_on_irqstack_cond arch/x86/include/asm/irq_stack.h:50 [inline] sysvec_apic_timer_interrupt+0x4c/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:__preempt_count_add arch/x86/include/asm/preempt.h:79 [inline] RIP: 0010:rcu_read_lock_sched_notrace include/linux/rcupdate.h:750 [inline] RIP: 0010:trace_timer_expire_entry include/trace/events/timer.h:90 [inline] RIP: 0010:call_timer_fn+0x595/0x760 kernel/time/timer.c:1412 Code: 65 ff 0d 0e dd 9d 7e 0f 94 c3 31 ff 89 de e8 d2 19 10 00 84 db 0f 84 8d fc ff ff e8 85 1d 10 00 e8 1f 55 9c ff e9 7e fc ff ff 76 1d 10 00 65 ff 05 df dc 9d 7e 48 8b 05 40 6f 49 09 e8 43 6e RSP: 0018:ffffc90000da8d20 EFLAGS: 00000202 RAX: 0000000000000000 RBX: ffff8881be3f5c10 RCX: ffffffff81641d94 RDX: 0000000000000001 RSI: ffff8881a751c340 RDI: 0000000000000001 RBP: 0000000000000101 R08: 0000000000000000 R09: ffffffff8ab2364f R10: 0000000000000000 R11: 0000000000000001 R12: ffffc90000da8d68 R13: 0000000000000001 R14: 1ffff920001b51a7 R15: ffff8880ae7255c0 expire_timers kernel/time/timer.c:1458 [inline] __run_timers.part.0+0x67c/0xaa0 kernel/time/timer.c:1755 __run_timers kernel/time/timer.c:1736 [inline] run_timer_softirq+0xae/0x1a0 kernel/time/timer.c:1768 __do_softirq+0x2de/0xa24 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+0x9d/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+0x1f3/0x230 kernel/softirq.c:435 sysvec_apic_timer_interrupt+0x51/0xf0 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:generic_exec_single+0x309/0x480 kernel/smp.c:172 Code: 00 fc ff df 48 c1 e8 03 80 3c 10 00 0f 85 63 01 00 00 48 83 3d ef 09 4d 08 00 0f 84 dc 00 00 00 e8 2c 0d 0b 00 48 89 df 57 9d <0f> 1f 44 00 00 45 31 e4 e9 e1 fd ff ff e8 15 0d 0b 00 0f 0b e9 42 RSP: 0018:ffffc90021ce7b08 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 0000000000000293 RCX: 0000000000000006 RDX: ffff8881a751c340 RSI: ffffffff816931e4 RDI: 0000000000000293 RBP: 0000000000000200 R08: 0000000000000001 R09: ffffffff8c5f3abf R10: fffffbfff18be757 R11: 0000000000000001 R12: ffffc90021ce7b80 R13: ffffffff818db6a0 R14: ffffc90021ce7c48 R15: 1ffff9200439cf9e smp_call_function_single+0x186/0x4f0 kernel/smp.c:379 task_function_call+0xd7/0x160 kernel/events/core.c:116 perf_install_in_context+0x2cb/0x550 kernel/events/core.c:2895 __do_sys_perf_event_open+0x1c31/0x2cb0 kernel/events/core.c:11992 do_syscall_64+0x2d/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45d5b9 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:00007fa91f2fec78 EFLAGS: 00000246 ORIG_RAX: 000000000000012a RAX: ffffffffffffffda RBX: 0000000000024640 RCX: 000000000045d5b9 RDX: ffffffffffffffff RSI: 0000000000000000 RDI: 0000000020000100 RBP: 000000000118cf90 R08: 0000000000000000 R09: 0000000000000000 R10: ffffffffffffffff R11: 0000000000000246 R12: 000000000118cf4c R13: 00007ffe2592dcbf R14: 00007fa91f2ff9c0 R15: 000000000118cf4c