rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 1, t=10502 jiffies, g=29065, q=57 ncpus=2) rcu: All QSes seen, last rcu_preempt kthread activity 10502 (4294970142-4294959640), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 10502 jiffies! g29065 f0x2 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:26712 pid:16 ppid:2 flags:0x00004008 Call Trace: sched_show_task+0x4d5/0x670 kernel/sched/core.c:8942 rcu_check_gp_kthread_starvation+0x180/0x220 kernel/rcu/tree_stall.h:515 print_other_cpu_stall+0x150c/0x1640 kernel/rcu/tree_stall.h:625 check_cpu_stall kernel/rcu/tree_stall.h:778 [inline] rcu_pending kernel/rcu/tree.c:3890 [inline] rcu_sched_clock_irq+0xaf6/0x1200 kernel/rcu/tree.c:2393 update_process_times+0x147/0x1b0 kernel/time/timer.c:1869 tick_sched_handle kernel/time/tick-sched.c:254 [inline] tick_sched_timer+0x386/0x550 kernel/time/tick-sched.c:1501 __run_hrtimer kernel/time/hrtimer.c:1686 [inline] __hrtimer_run_queues+0x5a7/0xe50 kernel/time/hrtimer.c:1750 hrtimer_interrupt+0x392/0x980 kernel/time/hrtimer.c:1812 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1095 [inline] __sysvec_apic_timer_interrupt+0x156/0x580 arch/x86/kernel/apic/apic.c:1112 sysvec_apic_timer_interrupt+0x8c/0xb0 arch/x86/kernel/apic/apic.c:1106 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5124 Code: 2e 0b 00 48 83 c4 08 4c 89 f7 e8 98 30 00 00 0f 1f 44 00 00 4c 89 f7 e8 7b 23 36 09 e8 06 1e 32 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28 RSP: 0018:ffffc90000157808 EFLAGS: 00000286 RAX: a3961690ec95fa00 RBX: ffff88807d583bb4 RCX: ffffffff91c95103 RDX: dffffc0000000000 RSI: ffffffff8aec0240 RDI: ffff88813fed6f38 RBP: ffffc90000157850 R08: dffffc0000000000 R09: ffffed1017327541 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88813fed5940 R13: 1ffff110173276eb R14: ffff8880b993aa00 R15: ffff8880b993b758 context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1435/0x4550 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:instrument_atomic_read include/linux/instrumented.h:72 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] RIP: 0010:test_ti_thread_flag include/linux/thread_info.h:118 [inline] RIP: 0010:need_resched include/linux/sched.h:2231 [inline] RIP: 0010:schedule+0xcc/0x180 kernel/sched/core.c:6636 Code: eb 0a 49 f7 04 24 08 00 00 00 74 39 bf 01 00 00 00 e8 48 c6 ca f6 31 ff e8 f1 b9 ff ff bf 01 00 00 00 e8 b7 c7 ca f6 4c 89 e7 08 00 00 00 e8 8a 7a 4e f7 42 80 3c 3b 00 74 c7 4c 89 e7 e8 eb RSP: 0018:ffffc90000157b98 EFLAGS: 00000257 RAX: 0000000000000001 RBX: 1ffff11027fdab28 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8aec0240 RDI: ffff88813fed5940 RBP: ffffc90000157cb0 R08: dffffc0000000000 R09: ffffed1017327541 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88813fed5940 R13: 1ffff9200002af78 R14: ffff88813fed6bb8 R15: dffffc0000000000 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 PID: 16 Comm: rcu_preempt Not tainted 6.1.94-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/07/2024 RIP: 0010:finish_task_switch+0x1d3/0x810 kernel/sched/core.c:5124 Code: 2e 0b 00 48 83 c4 08 4c 89 f7 e8 98 30 00 00 0f 1f 44 00 00 4c 89 f7 e8 7b 23 36 09 e8 06 1e 32 00 fb 49 8d bc 24 f8 15 00 00 <48> 89 f8 48 c1 e8 03 49 bd 00 00 00 00 00 fc ff df 42 0f b6 04 28 RSP: 0018:ffffc90000157808 EFLAGS: 00000286 RAX: a3961690ec95fa00 RBX: ffff88807d583bb4 RCX: ffffffff91c95103 RDX: dffffc0000000000 RSI: ffffffff8aec0240 RDI: ffff88813fed6f38 RBP: ffffc90000157850 R08: dffffc0000000000 R09: ffffed1017327541 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88813fed5940 R13: 1ffff110173276eb R14: ffff8880b993aa00 R15: ffff8880b993b758 FS: 0000000000000000(0000) GS:ffff8880b9900000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fc2b014df78 CR3: 000000005d65d000 CR4: 00000000003506e0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: context_switch kernel/sched/core.c:5248 [inline] __schedule+0x1435/0x4550 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:instrument_atomic_read include/linux/instrumented.h:72 [inline] RIP: 0010:_test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] RIP: 0010:test_ti_thread_flag include/linux/thread_info.h:118 [inline] RIP: 0010:need_resched include/linux/sched.h:2231 [inline] RIP: 0010:schedule+0xcc/0x180 kernel/sched/core.c:6636 Code: eb 0a 49 f7 04 24 08 00 00 00 74 39 bf 01 00 00 00 e8 48 c6 ca f6 31 ff e8 f1 b9 ff ff bf 01 00 00 00 e8 b7 c7 ca f6 4c 89 e7 08 00 00 00 e8 8a 7a 4e f7 42 80 3c 3b 00 74 c7 4c 89 e7 e8 eb RSP: 0018:ffffc90000157b98 EFLAGS: 00000257 RAX: 0000000000000001 RBX: 1ffff11027fdab28 RCX: 0000000000000001 RDX: dffffc0000000000 RSI: ffffffff8aec0240 RDI: ffff88813fed5940 RBP: ffffc90000157cb0 R08: dffffc0000000000 R09: ffffed1017327541 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88813fed5940 R13: 1ffff9200002af78 R14: ffff88813fed6bb8 R15: dffffc0000000000 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 vkms_vblank_simulate: vblank timer overrun