rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P20/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=13777, q=560 ncpus=2)
task:rcuc/0          state:R  running task     stack:20200 pid:20    tgid:20    ppid:2      task_flags:0x4208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1480/0x50a0 kernel/sched/core.c:6863
 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7190
 irqentry_exit+0x5d8/0x660 kernel/entry/common.c:216
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
RIP: 0010:lock_release+0x2a6/0x3b0 kernel/locking/lockdep.c:5893
Code: 4d 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 52 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 4a c9 0f 10 <48> 3b 44 24 28 75 75 48 83 c4 30 5b 41 5c 41 5d 41 5e 41 5f 5d c3
RSP: 0018:ffffc90000197858 EFLAGS: 00000206
RAX: bd0b6b8f68debf00 RBX: 0000000000000287 RCX: bd0b6b8f68debf00
RDX: 000000005f479b93 RSI: ffffffff8cfd3ade RDI: ffffffff8b3ede60
RBP: ffff88801ba8e650 R08: ffffffff81852ff1 R09: ffffffff8d5aecc0
R10: 0000000000000000 R11: fffffbfff1db4c2f R12: 0000000000000001
R13: 0000000000000001 R14: ffffffff8d44e9c0 R15: ffff88801ba8dac0
 __local_bh_enable_ip+0x115/0x2e0 kernel/softirq.c:268
 local_bh_enable include/linux/bottom_half.h:33 [inline]
 rcu_do_batch kernel/rcu/tree.c:2624 [inline]
 rcu_core kernel/rcu/tree.c:2857 [inline]
 rcu_cpu_kthread+0xcdd/0x1c40 kernel/rcu/tree.c:2945
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10310 jiffies! g13777 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=8303
rcu: rcu_preempt kthread starved for 10311 jiffies! g13777 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:26936 pid:18    tgid:18    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5256 [inline]
 __schedule+0x1480/0x50a0 kernel/sched/core.c:6863
 __schedule_loop kernel/sched/core.c:6945 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:6960
 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99
 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083
 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 7005 Comm: vhost-7004 Tainted: G             L      syzkaller #0 PREEMPT_{RT,(full)} 
Tainted: [L]=SOFTLOCKUP
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025
RIP: 0010:__raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline]
RIP: 0010:_raw_spin_unlock_irqrestore+0xa8/0x110 kernel/locking/spinlock.c:194
Code: 74 05 e8 7b af fd f6 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f6 44 24 21 02 75 4f f7 c3 00 02 00 00 74 01 fb bf 01 00 00 00 <e8> 33 48 c6 f6 65 8b 05 fc 85 e2 06 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc90003da7880 EFLAGS: 00000206
RAX: c6c5b85ac0858d00 RBX: 0000000000000a02 RCX: c6c5b85ac0858d00
RDX: 0000000000000006 RSI: ffffffff8cdfcc79 RDI: 0000000000000001
RBP: ffffc90003da7910 R08: ffffffff8eda6177 R09: 1ffffffff1db4c2e
R10: dffffc0000000000 R11: fffffbfff1db4c2f R12: dffffc0000000000
R13: 0000000000000a02 R14: ffff888032abd508 R15: 1ffff920007b4f10
FS:  00007fdc805956c0(0000) GS:ffff888126e52000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 0000000000000002 CR3: 0000000063378000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 raw_spin_unlock_irqrestore_wake include/linux/sched/wake_q.h:94 [inline]
 rtlock_slowlock kernel/locking/rtmutex.c:1896 [inline]
 rtlock_lock kernel/locking/spinlock_rt.c:43 [inline]
 __rt_spin_lock kernel/locking/spinlock_rt.c:49 [inline]
 rt_spin_lock+0x16d/0x3e0 kernel/locking/spinlock_rt.c:57
 spin_lock include/linux/spinlock_rt.h:44 [inline]
 eventfd_signal_mask+0x7c/0x1e0 fs/eventfd.c:71
 eventfd_signal include/linux/eventfd.h:89 [inline]
 vhost_get_avail_idx+0x213/0x3f0 drivers/vhost/vhost.c:1533
 vhost_enable_notify+0x303/0x600 drivers/vhost/vhost.c:3245
 vhost_transport_do_send_pkt+0xfa5/0x13b0 drivers/vhost/vsock.c:125
 vhost_run_work_list+0x14e/0x1e0 drivers/vhost/vhost.c:454
 vhost_task_fn+0x27c/0x430 kernel/vhost_task.c:49
 ret_from_fork+0x599/0xb30 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:246
 </TASK>