rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=502/1/0x4000000000000000 softirq=102521/102523 fqs=4 (detected by 0, t=10502 jiffies, g=167105, q=239) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 PID: 6849 Comm: syz-executor.3 Not tainted 5.9.0-rc7-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 01/01/2011 RIP: 0010:arch_atomic64_read arch/x86/include/asm/atomic64_64.h:22 [inline] RIP: 0010:atomic64_read include/asm-generic/atomic-instrumented.h:838 [inline] RIP: 0010:taprio_set_budget net/sched/sch_taprio.c:519 [inline] RIP: 0010:advance_sched+0x666/0x8c0 net/sched/sch_taprio.c:744 Code: 83 c3 20 8b 45 00 4c 69 f0 e8 03 00 00 49 8d 6f a0 48 89 ef be 08 00 00 00 e8 96 7f ef fa 48 89 e8 48 c1 e8 03 42 80 3c 28 00 <74> 08 48 89 ef e8 80 b0 ef fa 4c 89 f0 31 d2 48 f7 75 00 48 89 c5 RSP: 0018:ffffc90000da8d20 EFLAGS: 00000046 RAX: 1ffff110129b705c RBX: ffff888091545320 RCX: ffffffff86c5312a RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffff888094db82e0 RBP: ffff888094db82e0 R08: dffffc0000000000 R09: ffffed10129b705d R10: ffffed10129b705d R11: 0000000000000000 R12: 16ea40242dd48048 R13: dffffc0000000000 R14: 000001f4000003e8 R15: ffff888094db8340 FS: 0000000003685940(0000) GS:ffff8880ae900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b2fc21000 CR3: 0000000051d0b000 CR4: 00000000001506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1524 [inline] __hrtimer_run_queues+0x47f/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 asm_call_irq_on_stack+0xf/0x20 __run_sysvec_on_irqstack arch/x86/include/asm/irq_stack.h:37 [inline] run_sysvec_on_irqstack_cond arch/x86/include/asm/irq_stack.h:89 [inline] sysvec_apic_timer_interrupt+0x94/0xf0 arch/x86/kernel/apic/apic.c:1091 asm_sysvec_apic_timer_interrupt+0x12/0x20 arch/x86/include/asm/idtentry.h:581 RIP: 0010:__raw_spin_unlock_irq include/linux/spinlock_api_smp.h:169 [inline] RIP: 0010:_raw_spin_unlock_irq+0x57/0x80 kernel/locking/spinlock.c:199 Code: 00 00 00 00 fc ff df 80 3c 08 00 74 0c 48 c7 c7 c8 17 6d 89 e8 ca c1 66 f9 48 83 3d ca f7 1e 01 00 74 25 fb 66 0f 1f 44 00 00 01 00 00 00 e8 1f b3 02 f9 65 8b 05 f4 dd b3 77 85 c0 74 02 5b RSP: 0018:ffffc900056d7cc8 EFLAGS: 00000286 RAX: 1ffffffff12da2f9 RBX: ffff8880ae9358c0 RCX: dffffc0000000000 RDX: 0000000040000000 RSI: 0000000000000002 RDI: 0000000000000000 RBP: ffffc900056d7d28 R08: ffffffff817ac190 R09: ffffed1015d26b19 R10: ffffed1015d26b19 R11: 0000000000000000 R12: ffff8880ae9358c0 R13: ffff888051d20280 R14: ffff8880ae936308 R15: dffffc0000000000 finish_task_switch+0x24f/0x550 kernel/sched/core.c:3617 context_switch kernel/sched/core.c:3781 [inline] __schedule+0x9c1/0xd20 kernel/sched/core.c:4527 schedule+0x188/0x220 kernel/sched/core.c:4602 freezable_schedule include/linux/freezer.h:172 [inline] do_nanosleep+0x1ae/0x680 kernel/time/hrtimer.c:1883 hrtimer_nanosleep kernel/time/hrtimer.c:1936 [inline] __do_sys_nanosleep kernel/time/hrtimer.c:1970 [inline] __se_sys_nanosleep+0x3d5/0x5c0 kernel/time/hrtimer.c:1957 do_syscall_64+0x31/0x70 arch/x86/entry/common.c:46 entry_SYSCALL_64_after_hwframe+0x44/0xa9 RIP: 0033:0x45c261 Code: 75 14 b8 23 00 00 00 0f 05 48 3d 01 f0 ff ff 0f 83 34 cf fb ff c3 48 83 ec 08 e8 ea 46 00 00 48 89 04 24 b8 23 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 33 47 00 00 48 89 d0 48 83 c4 08 48 3d 01 RSP: 002b:00007fffb0707770 EFLAGS: 00000293 ORIG_RAX: 0000000000000023 RAX: ffffffffffffffda RBX: 00000000000f3bd1 RCX: 000000000045c261 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 00007fffb0707780 RBP: 0000000000000f7b R08: 0000000000000000 R09: 0000000003685940 R10: 0000000000000000 R11: 0000000000000293 R12: 0000000000000001 R13: 00007fffb07077d0 R14: 00000000000f3ba9 R15: 00007fffb07077e0 rcu: rcu_preempt kthread starved for 10494 jiffies! g167105 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:28896 pid: 10 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:3778 [inline] __schedule+0x9b9/0xd20 kernel/sched/core.c:4527