rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3849/1:b..l (detected by 0, t=10502 jiffies, g=64877, q=190 ncpus=2) task:kworker/u4:8 state:R running task stack:19608 pid:3849 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6561 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6873 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:__preempt_count_add kernel/rcu/tree.c:717 [inline] RIP: 0010:rcu_is_watching+0x4/0xb0 kernel/rcu/tree.c:720 Code: 21 02 0f 84 02 ff ff ff e9 6c ff ff ff 48 c7 c7 a0 16 33 8d 4c 89 f6 e8 ba 8d f0 02 e9 2b ff ff ff e8 f0 87 31 09 41 57 41 56 <53> 65 ff 05 ec 1c 8f 7e e8 2f a0 31 09 89 c3 83 f8 08 73 76 49 bf RSP: 0018:ffffc90004787be0 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 0000000000000001 RCX: ffff888022408000 RDX: ffff888022408000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: 0000000000000000 R08: ffffffff8a75ba6a R09: fffffbfff20e7245 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff88805ce58c80 R13: 00000000000000c1 R14: ffff888059a915c0 R15: dffffc0000000000 rcu_read_unlock include/linux/rcupdate.h:820 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:412 [inline] batadv_nc_worker+0x203/0x610 net/batman-adv/network-coding.c:719 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 rcu: rcu_preempt kthread starved for 9130 jiffies! g64877 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:26136 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5244 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6561 schedule+0xbf/0x180 kernel/sched/core.c:6637 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:295 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 PID: 0 Comm: swapper/0 Not tainted 6.1.102-syzkaller #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 06/27/2024 RIP: 0010:native_save_fl arch/x86/include/asm/irqflags.h:22 [inline] RIP: 0010:arch_local_save_flags arch/x86/include/asm/irqflags.h:70 [inline] RIP: 0010:arch_irqs_disabled arch/x86/include/asm/irqflags.h:130 [inline] RIP: 0010:acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline] RIP: 0010:acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:567 Code: 6c db f6 48 83 e3 08 0f 85 0b 01 00 00 4c 8d 74 24 20 e8 34 2b e2 f6 0f 1f 44 00 00 e8 6a 68 db f6 0f 00 2d b3 4d b8 00 fb f4 <4c> 89 f3 48 c1 eb 03 42 80 3c 3b 00 74 08 4c 89 f7 e8 bb f0 32 f7 RSP: 0018:ffffffff8d007b20 EFLAGS: 000002d3 RAX: ffffffff8aaf3326 RBX: 0000000000000000 RCX: ffffffff8d0bd800 RDX: 0000000000000000 RSI: ffffffff8b0c0240 RDI: ffffffff8b5d5ba0 RBP: ffffffff8d007bb0 R08: ffffffff8aaf3308 R09: fffffbfff1a17b01 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffffffff1a00f64 R13: ffff8880139a7804 R14: ffffffff8d007b40 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b9800000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0cfd8856c0 CR3: 0000000029fdc000 CR4: 00000000003506f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: acpi_idle_enter+0x352/0x4f0 drivers/acpi/processor_idle.c:704 cpuidle_enter_state+0x516/0xf80 drivers/cpuidle/cpuidle.c:239 cpuidle_enter+0x59/0x90 drivers/cpuidle/cpuidle.c:356 call_cpuidle kernel/sched/idle.c:155 [inline] cpuidle_idle_call kernel/sched/idle.c:236 [inline] do_idle+0x3ce/0x680 kernel/sched/idle.c:303 cpu_startup_entry+0x3d/0x60 kernel/sched/idle.c:401 rest_init+0x2da/0x300 init/main.c:733 arch_call_rest_init+0xa/0xa init/main.c:893 start_kernel+0x496/0x53f init/main.c:1140 secondary_startup_64_no_verify+0xcf/0xdb