rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P29
rcu: 	(detected by 1, t=10502 jiffies, g=12801, q=5703 ncpus=2)
task:ktimers/1       state:R  running task     stack:25560 pid:29    tgid:29    ppid:2      task_flags:0x4208040 flags:0x00080000
Call Trace:
 <IRQ>
 sched_show_task+0x49d/0x630 kernel/sched/core.c:7901
 rcu_print_detail_task_stall_rnp kernel/rcu/tree_stall.h:292 [inline]
 print_other_cpu_stall+0xf78/0x1340 kernel/rcu/tree_stall.h:681
 check_cpu_stall kernel/rcu/tree_stall.h:857 [inline]
 rcu_pending kernel/rcu/tree.c:3671 [inline]
 rcu_sched_clock_irq+0xa47/0x11b0 kernel/rcu/tree.c:2706
 update_process_times+0x235/0x2d0 kernel/time/timer.c:2473
 tick_sched_handle kernel/time/tick-sched.c:276 [inline]
 tick_nohz_handler+0x39a/0x520 kernel/time/tick-sched.c:297
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x506/0xd40 kernel/time/hrtimer.c:1841
 hrtimer_interrupt+0x45d/0xa90 kernel/time/hrtimer.c:1903
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline]
 __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058
 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline]
 sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052
 </IRQ>
 <TASK>
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697
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 ab 9f 02 f7 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> 73 d7 cb f6 65 8b 05 0c 8e de 06 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc90000a3f720 EFLAGS: 00000206
RAX: 5275616750436b00 RBX: 0000000000000a06 RCX: 5275616750436b00
RDX: 0000000000000002 RSI: ffffffff8cd8d6e1 RDI: 0000000000000001
RBP: ffffc90000a3f7b0 R08: ffffffff8ed63077 R09: 1ffffffff1dac60e
R10: dffffc0000000000 R11: fffffbfff1dac60f R12: dffffc0000000000
R13: ffff88803612f428 R14: ffff88803612f428 R15: 1ffff92000147ee4
 unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline]
 rt_mutex_slowunlock+0x493/0x8a0 kernel/locking/rtmutex.c:1454
 spin_unlock include/linux/spinlock_rt.h:105 [inline]
 advance_sched+0x9a8/0xc90 net/sched/sch_taprio.c:986
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x552/0xd40 kernel/time/hrtimer.c:1841
 hrtimer_run_softirq+0x1a3/0x2e0 kernel/time/hrtimer.c:1858
 handle_softirqs+0x22f/0x710 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 run_ktimerd+0xcf/0x190 kernel/softirq.c:1138
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: rcu_preempt kthread timer wakeup didn't happen for 10499 jiffies! g12801 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402
rcu: 	Possible timer handling issue on cpu=1 timer-softirq=6758
rcu: rcu_preempt kthread starved for 10500 jiffies! g12801 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:27352 pid:18    tgid:18    ppid:2      task_flags:0x208040 flags:0x00080000
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5325 [inline]
 __schedule+0x16f3/0x4c20 kernel/sched/core.c:6929
 __schedule_loop kernel/sched/core.c:7011 [inline]
 schedule+0x165/0x360 kernel/sched/core.c:7026
 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+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>
rcu: Stack dump where RCU GP kthread last ran:
CPU: 1 UID: 0 PID: 29 Comm: ktimers/1 Not tainted syzkaller #0 PREEMPT_{RT,(full)} 
Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025
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 ab 9f 02 f7 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> 73 d7 cb f6 65 8b 05 0c 8e de 06 85 c0 74 40 48 c7 04 24 0e 36
RSP: 0018:ffffc90000a3f720 EFLAGS: 00000206
RAX: 5275616750436b00 RBX: 0000000000000a06 RCX: 5275616750436b00
RDX: 0000000000000002 RSI: ffffffff8cd8d6e1 RDI: 0000000000000001
RBP: ffffc90000a3f7b0 R08: ffffffff8ed63077 R09: 1ffffffff1dac60e
R10: dffffc0000000000 R11: fffffbfff1dac60f R12: dffffc0000000000
R13: ffff88803612f428 R14: ffff88803612f428 R15: 1ffff92000147ee4
FS:  0000000000000000(0000) GS:ffff888126ef9000(0000) knlGS:0000000000000000
CS:  0010 DS: 0000 ES: 0000 CR0: 0000000080050033
CR2: 00007fffee6affd8 CR3: 000000000d3a6000 CR4: 00000000003526f0
Call Trace:
 <TASK>
 unlock_rt_mutex_safe kernel/locking/rtmutex.c:344 [inline]
 rt_mutex_slowunlock+0x493/0x8a0 kernel/locking/rtmutex.c:1454
 spin_unlock include/linux/spinlock_rt.h:105 [inline]
 advance_sched+0x9a8/0xc90 net/sched/sch_taprio.c:986
 __run_hrtimer kernel/time/hrtimer.c:1777 [inline]
 __hrtimer_run_queues+0x552/0xd40 kernel/time/hrtimer.c:1841
 hrtimer_run_softirq+0x1a3/0x2e0 kernel/time/hrtimer.c:1858
 handle_softirqs+0x22f/0x710 kernel/softirq.c:622
 __do_softirq kernel/softirq.c:656 [inline]
 run_ktimerd+0xcf/0x190 kernel/softirq.c:1138
 smpboot_thread_fn+0x542/0xa60 kernel/smpboot.c:160
 kthread+0x711/0x8a0 kernel/kthread.c:463
 ret_from_fork+0x4bc/0x870 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>