sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P2740/1:b..l rcu: (detected by 0, t=10502 jiffies, g=175217, q=656 ncpus=1) task:syz.1.13514 state:R running task stack:23408 pid:2740 tgid:2738 ppid:6005 task_flags:0x400940 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 preempt_schedule_irq+0x50/0x90 kernel/sched/core.c:7235 irqentry_exit+0x17b/0x670 kernel/entry/common.c:239 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_acquire+0x5e/0x380 kernel/locking/lockdep.c:5872 Code: 05 bb e9 28 12 83 f8 07 0f 87 f0 00 00 00 48 0f a3 05 86 59 f5 0e 0f 82 c2 02 00 00 8b 35 4e 8d f5 0e 85 f6 0f 85 dd 00 00 00 <48> 8b 44 24 30 65 48 2b 05 5d e9 28 12 0f 85 02 03 00 00 48 83 c4 RSP: 0018:ffffc900059163f0 EFLAGS: 00000206 RAX: 0000000000000046 RBX: 0000000000000000 RCX: 0000000000000001 RDX: 0000000000000000 RSI: ffffffff8de55850 RDI: ffffffff8c1af520 RBP: ffffffff8e7e9220 R08: 0000000028bf3b1f R09: 0000000000000007 R10: 0000000000000200 R11: 0000000000000000 R12: 0000000000000002 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:312 [inline] rcu_read_lock include/linux/rcupdate.h:850 [inline] class_rcu_constructor include/linux/rcupdate.h:1193 [inline] unwind_next_frame+0xd1/0x1ea0 arch/x86/kernel/unwind_orc.c:495 arch_stack_walk+0x94/0xf0 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 save_stack+0x162/0x1e0 mm/page_owner.c:165 __reset_page_owner+0x84/0x190 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1433 [inline] free_unref_folios+0xaea/0x1790 mm/page_alloc.c:3040 shrink_folio_list+0x2f10/0x6000 mm/vmscan.c:1610 evict_folios+0x7fa/0x1e90 mm/vmscan.c:4718 try_to_shrink_lruvec+0x57e/0x990 mm/vmscan.c:4881 lru_gen_shrink_lruvec mm/vmscan.c:5030 [inline] shrink_lruvec+0x319/0x2a50 mm/vmscan.c:5784 shrink_node_memcgs mm/vmscan.c:6020 [inline] shrink_node+0x8e7/0x3e20 mm/vmscan.c:6061 shrink_zones mm/vmscan.c:6300 [inline] do_try_to_free_pages+0x340/0x1870 mm/vmscan.c:6362 try_to_free_mem_cgroup_pages+0x2b2/0x820 mm/vmscan.c:6683 try_charge_memcg+0x3e3/0xc90 mm/memcontrol.c:2414 try_charge mm/memcontrol.c:2556 [inline] charge_memcg+0xa6/0x280 mm/memcontrol.c:4744 __mem_cgroup_charge+0x2b/0x1e0 mm/memcontrol.c:4761 mem_cgroup_charge include/linux/memcontrol.h:664 [inline] folio_prealloc mm/memory.c:1211 [inline] alloc_anon_folio mm/memory.c:5208 [inline] do_anonymous_page+0xb62/0x1fb0 mm/memory.c:5265 do_pte_missing mm/memory.c:4475 [inline] handle_pte_fault mm/memory.c:6316 [inline] __handle_mm_fault+0x1d42/0x2b60 mm/memory.c:6454 handle_mm_fault+0x36d/0xa20 mm/memory.c:6623 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0xf9c/0x34d0 mm/gup.c:1428 populate_vma_page_range+0x267/0x3f0 mm/gup.c:1860 __mm_populate+0x107/0x3a0 mm/gup.c:1963 mm_populate include/linux/mm.h:3899 [inline] vm_mmap_pgoff+0x37f/0x470 mm/util.c:586 ksys_mmap_pgoff+0xe1/0x650 mm/mmap.c:605 __do_sys_mmap arch/x86/kernel/sys_x86_64.c:89 [inline] __se_sys_mmap arch/x86/kernel/sys_x86_64.c:82 [inline] __x64_sys_mmap+0x125/0x190 arch/x86/kernel/sys_x86_64.c:82 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x106/0xf80 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f329979c799 RSP: 002b:00007f329a5e0028 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f3299a15fa0 RCX: 00007f329979c799 RDX: 00000000000000df RSI: 0000000000400007 RDI: 0000000000000000 RBP: 00007f3299832bd9 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000009b72 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f3299a16038 R14: 00007f3299a15fa0 R15: 00007ffd2c76ed18 rcu: rcu_preempt kthread starved for 519 jiffies! g175217 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:27976 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5295 [inline] __schedule+0xfee/0x6120 kernel/sched/core.c:6908 __schedule_loop kernel/sched/core.c:6990 [inline] schedule+0xdd/0x390 kernel/sched/core.c:7005 schedule_timeout+0x127/0x280 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1a9/0x900 kernel/rcu/tree.c:2095 rcu_gp_kthread+0x179/0x230 kernel/rcu/tree.c:2297 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245 rcu: Stack dump where RCU GP kthread last ran: CPU: 0 UID: 0 PID: 3407 Comm: kworker/R-bat_e Tainted: G U W I L XTNJ syzkaller #0 PREEMPT(full) Tainted: [U]=USER, [W]=WARN, [I]=FIRMWARE_WORKAROUND, [L]=SOFTLOCKUP, [X]=AUX, [T]=RANDSTRUCT, [N]=TEST, [J]=FWCTL Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2026 Workqueue: bat_events batadv_dat_purge RIP: 0010:lockdep_enabled kernel/locking/lockdep.c:121 [inline] RIP: 0010:lock_is_held_type+0x17/0x140 kernel/locking/lockdep.c:5933 Code: 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 8b 0d ba a5 4c 05 b8 ff ff ff ff 85 c9 0f 84 ed 00 00 00 <65> 8b 15 4a 49 80 08 85 d2 0f 85 de 00 00 00 41 57 41 56 41 55 41 RSP: 0018:ffffc90000006f58 EFLAGS: 00000202 RAX: 00000000ffffffff RBX: ffff888075d42000 RCX: 0000000000000001 RDX: 0000000000000001 RSI: 00000000ffffffff RDI: ffffffff8e7e9220 RBP: 0000000000000000 R08: 0000000000000007 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: ffff888069bed100 R13: dffffc0000000000 R14: ffff888075d42000 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff88812434c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007fff1920ac6c CR3: 000000007cce6000 CR4: 00000000003526f0 Call Trace: dev_nit_active_rcu+0x15/0x130 net/core/dev.c:2536 xmit_one net/core/dev.c:3866 [inline] dev_hard_start_xmit+0x2d1/0x7d0 net/core/dev.c:3887 __dev_queue_xmit+0x32c1/0x4800 net/core/dev.c:4840 dev_queue_xmit include/linux/netdevice.h:3384 [inline] br_dev_queue_push_xmit+0x360/0x550 net/bridge/br_forward.c:53 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_forward_finish+0x102/0x4d0 net/bridge/br_forward.c:66 br_nf_hook_thresh+0x30d/0x420 net/bridge/br_netfilter_hooks.c:1167 br_nf_forward_finish+0x693/0xb30 net/bridge/br_netfilter_hooks.c:662 NF_HOOK include/linux/netfilter.h:318 [inline] NF_HOOK include/linux/netfilter.h:312 [inline] br_nf_forward_arp net/bridge/br_netfilter_hooks.c:752 [inline] br_nf_forward+0x157a/0x19f0 net/bridge/br_netfilter_hooks.c:775 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xbf/0x220 net/netfilter/core.c:623 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK include/linux/netfilter.h:316 [inline] __br_forward+0x2f6/0x970 net/bridge/br_forward.c:115 deliver_clone net/bridge/br_forward.c:131 [inline] maybe_deliver+0xf0/0x180 net/bridge/br_forward.c:191 br_flood+0x193/0x650 net/bridge/br_forward.c:238 br_handle_frame_finish+0xf57/0x1f00 net/bridge/br_input.c:229 nf_hook_bridge_pre net/bridge/br_input.c:313 [inline] br_handle_frame+0x977/0x1520 net/bridge/br_input.c:442 __netif_receive_skb_core.constprop.0+0x6c5/0x3550 net/core/dev.c:6054 __netif_receive_skb_one_core+0xb0/0x1e0 net/core/dev.c:6165 __netif_receive_skb+0x1f/0x120 net/core/dev.c:6280 process_backlog+0x37a/0x1580 net/core/dev.c:6631 __napi_poll.constprop.0+0xaf/0x450 net/core/dev.c:7695 napi_poll net/core/dev.c:7758 [inline] net_rx_action+0xa40/0xf20 net/core/dev.c:7910 handle_softirqs+0x1eb/0x9e0 kernel/softirq.c:622 do_softirq kernel/softirq.c:523 [inline] do_softirq+0xac/0xe0 kernel/softirq.c:510 __local_bh_enable_ip+0xf8/0x120 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:395 [inline] __batadv_dat_purge.part.0+0x294/0x3c0 net/batman-adv/distributed-arp-table.c:185 __batadv_dat_purge net/batman-adv/distributed-arp-table.c:166 [inline] batadv_dat_purge+0x4b/0xa0 net/batman-adv/distributed-arp-table.c:204 process_one_work+0x9d7/0x1920 kernel/workqueue.c:3275 process_scheduled_works kernel/workqueue.c:3358 [inline] rescuer_thread+0x902/0x1490 kernel/workqueue.c:3582 kthread+0x370/0x450 kernel/kthread.c:467 ret_from_fork+0x754/0xd80 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245