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): P19765/1:b..l P5628/1:b..l P5647/1:b..l rcu: (detected by 0, t=10502 jiffies, g=138509, q=794 ncpus=1) task:udevd state:R running task stack:23400 pid:5647 tgid:5647 ppid:4986 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674 RIP: 0010:unwind_next_frame+0xd09/0x2550 arch/x86/kernel/unwind_orc.c:645 Code: 18 74 08 48 89 df e8 06 10 bd 00 48 8b 04 24 48 89 03 ba 10 00 00 00 49 8d 5e 50 48 89 df 31 f6 e8 cc 11 bd 00 48 8b 54 24 08 c7 04 00 00 48 89 5c 24 48 49 8d 7e 08 48 89 fb 48 c1 eb 03 42 RSP: 0018:ffffc9000475f160 EFLAGS: 00000202 RAX: ffffc9000475f258 RBX: ffffc9000475f258 RCX: 0000000000000000 RDX: ffffffff90fa6c12 RSI: 0000000000000000 RDI: ffffc9000475f268 RBP: 1ffffffff21f4d82 R08: ffffc9000475f267 R09: ffffc9000475f258 R10: dffffc0000000000 R11: fffff520008ebe4d R12: dffffc0000000000 R13: ffffffff90fa6c0e R14: ffffc9000475f208 R15: ffffc9000475f250 arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] free_unref_folios+0xd84/0x14a0 mm/page_alloc.c:3011 folios_put_refs+0x9e9/0xb30 mm/swap.c:1057 folio_batch_release include/linux/folio_batch.h:101 [inline] shmem_undo_range+0x4e6/0x15d0 mm/shmem.c:1159 shmem_truncate_range mm/shmem.c:1287 [inline] shmem_evict_inode+0x280/0xa80 mm/shmem.c:1417 evict+0x624/0xb50 fs/inode.c:825 dentry_kill+0x1b9/0x880 fs/dcache.c:826 finish_dput+0x1a/0x260 fs/dcache.c:1001 __fput+0x675/0xa50 fs/file_table.c:520 task_work_run+0x1d9/0x270 kernel/task_work.c:233 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] __exit_to_user_mode_loop kernel/entry/common.c:70 [inline] exit_to_user_mode_loop+0x1fa/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f21002a7407 RSP: 002b:00007fff7841e560 EFLAGS: 00000202 ORIG_RAX: 0000000000000003 RAX: 0000000000000000 RBX: 00007f21009eb880 RCX: 00007f21002a7407 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000008 RBP: 00007f21009eb6e8 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000000000000002 R13: 0000561c41fac190 R14: 0000000000000008 R15: 0000561c41fb2ba0 task:syz-executor state:R running task stack:22352 pid:5628 tgid:5628 ppid:5621 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7556 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:539 [inline] irqentry_exit+0x14f/0x8f0 kernel/entry/common.c:167 asm_common_interrupt+0x26/0x40 arch/x86/include/asm/idtentry.h:665 RIP: 0010:orc_find arch/x86/kernel/unwind_orc.c:222 [inline] RIP: 0010:unwind_next_frame+0x1d6/0x2550 arch/x86/kernel/unwind_orc.c:510 Code: fd f8 a4 d5 8b 0f 93 c1 08 c1 0f 85 0b 01 00 00 48 c7 c0 00 00 00 81 49 89 ef 49 29 c7 49 c1 ef 08 8b 15 7d 49 d8 0c 8d 42 ff <44> 39 f8 0f 86 6c 04 00 00 44 89 f8 4c 8d 2c 85 f8 07 9e 91 4c 89 RSP: 0018:ffffc9000462f100 EFLAGS: 00000213 RAX: 00000000000ad5a5 RBX: 0000000000000001 RCX: 0000000080000000 RDX: 00000000000ad5a6 RSI: ffffffff8c4bdd60 RDI: ffffffff8c4bdd20 RBP: ffffffff8234bfe8 R08: ffffffff8177927f R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: dffffc0000000000 R13: ffffffff8177927f R14: ffffc9000462f1a8 R15: 00000000000134bf arch_stack_walk+0x11b/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0xa9/0x100 kernel/stacktrace.c:122 save_stack+0x122/0x230 mm/page_owner.c:165 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:320 reset_page_owner include/linux/page_owner.h:25 [inline] __free_pages_prepare mm/page_alloc.c:1406 [inline] __free_frozen_pages+0xc1e/0xd10 mm/page_alloc.c:2950 __slab_free+0x274/0x2c0 mm/slub.c:5741 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x99/0x100 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:350 kasan_slab_alloc include/linux/kasan.h:253 [inline] slab_post_alloc_hook mm/slub.c:4584 [inline] slab_alloc_node mm/slub.c:4917 [inline] kmem_cache_alloc_noprof+0x2a0/0x5f0 mm/slub.c:4931 anon_vma_chain_alloc mm/rmap.c:142 [inline] anon_vma_clone+0x3e7/0x9e0 mm/rmap.c:342 anon_vma_fork+0x177/0x540 mm/rmap.c:404 dup_mmap+0x970/0x1d90 mm/mmap.c:1803 dup_mm kernel/fork.c:1543 [inline] copy_mm+0x11a/0x480 kernel/fork.c:1595 copy_process+0x1e3e/0x4390 kernel/fork.c:2289 kernel_clone+0x2d7/0x940 kernel/fork.c:2748 __do_sys_clone kernel/fork.c:2889 [inline] __se_sys_clone kernel/fork.c:2873 [inline] __x64_sys_clone+0x1b6/0x230 kernel/fork.c:2873 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0x174/0x580 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f4a5ebc6a92 RSP: 002b:00007fffa5c57990 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007fffa5c57990 RCX: 00007f4a5ebc6a92 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007fffa5c57b1c R08: 0000000000000000 R09: 0000000000000001 R10: 00005555598f17d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 00000000000b2c22 R15: 00007fffa5c57b70 task:syz.2.5291 state:R running task stack:26856 pid:19765 tgid:19764 ppid:5631 task_flags:0x40044c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_common+0x82/0xd0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:169 [inline] _raw_spin_unlock+0x3f/0x50 kernel/locking/spinlock.c:190 spin_unlock include/linux/spinlock.h:390 [inline] zap_pte_range mm/memory.c:1964 [inline] zap_pmd_range mm/memory.c:2020 [inline] zap_pud_range mm/memory.c:2048 [inline] zap_p4d_range mm/memory.c:2069 [inline] __zap_vma_range+0x4084/0x4f10 mm/memory.c:2109 unmap_vmas+0x390/0x550 mm/memory.c:2178 exit_mmap+0x293/0x9f0 mm/mmap.c:1300 __mmput+0x118/0x420 kernel/fork.c:1187 exit_mm+0x221/0x2d0 kernel/exit.c:615 do_exit+0x6cd/0x2360 kernel/exit.c:997 do_group_exit+0x22d/0x2f0 kernel/exit.c:1152 get_signal+0x121b/0x12c0 kernel/signal.c:3046 arch_do_signal_or_restart+0xbb/0x860 arch/x86/kernel/signal.c:337 __exit_to_user_mode_loop kernel/entry/common.c:66 [inline] exit_to_user_mode_loop+0x104/0x730 kernel/entry/common.c:101 __exit_to_user_mode_prepare include/linux/irq-entry-common.h:207 [inline] syscall_exit_to_user_mode_prepare include/linux/irq-entry-common.h:230 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:318 [inline] do_syscall_64+0x353/0x580 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f505f79e019 RSP: 002b:00007f50606720e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f505fa25fa8 RCX: 00007f505f79e019 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f505fa25fa8 RBP: 00007f505fa25fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f505fa26038 R14: 00007ffdbecb78d0 R15: 00007ffdbecb79b8 rcu: rcu_preempt kthread starved for 1775 jiffies! g138509 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:27496 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 __schedule_loop kernel/sched/core.c:7311 [inline] schedule+0x164/0x2b0 kernel/sched/core.c:7326 schedule_timeout+0x152/0x2c0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x30c/0x11f0 kernel/rcu/tree.c:2123 rcu_gp_kthread+0x9e/0x2b0 kernel/rcu/tree.c:2325 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 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: 3222 Comm: kworker/R-bat_e Tainted: G L syzkaller #0 PREEMPT(full) Tainted: [L]=SOFTLOCKUP Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 07/16/2026 Workqueue: bat_events batadv_tt_purge RIP: 0010:memset+0xf/0x30 arch/x86/lib/memset_64.S:38 Code: 44 88 1f e9 8e 64 3e f5 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 49 89 f9 40 88 f0 48 89 d1 aa 4c 89 c8 e9 62 64 3e f5 90 90 90 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffc900000078b8 EFLAGS: 00000202 RAX: 0000000000000000 RBX: 1ffff92000000f3c RCX: 000000000000000c RDX: 0000000000000020 RSI: 0000000000000000 RDI: ffffc90000007a24 RBP: ffffc90000007ac0 R08: ffffc90000007a2f R09: ffffc90000007a10 R10: dffffc0000000000 R11: fffff52000000f46 R12: ffff888029d19280 R13: dffffc0000000000 R14: ffffc90000007a10 R15: ffffc90000007b80 FS: 0000000000000000(0000) GS:ffff888124f4c000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f13e2257dbf CR3: 0000000076ca0000 CR4: 0000000000350ef0 Call Trace: ip6t_do_table+0xd5/0x15b0 net/ipv6/netfilter/ip6_tables.c:261 nf_hook_entry_hookfn include/linux/netfilter.h:158 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:619 nf_hook include/linux/netfilter.h:273 [inline] NF_HOOK+0x21f/0x3c0 include/linux/netfilter.h:316 __netif_receive_skb_one_core net/core/dev.c:6212 [inline] __netif_receive_skb net/core/dev.c:6325 [inline] process_backlog+0x774/0x1860 net/core/dev.c:6676 __napi_poll+0xaa/0x330 net/core/dev.c:7735 napi_poll net/core/dev.c:7798 [inline] net_rx_action+0x61d/0xf50 net/core/dev.c:7955 handle_softirqs+0x225/0x840 kernel/softirq.c:622 do_softirq+0x76/0xd0 kernel/softirq.c:523 __local_bh_enable_ip+0xf8/0x130 kernel/softirq.c:450 spin_unlock_bh include/linux/spinlock.h:396 [inline] batadv_tt_global_purge net/batman-adv/translation-table.c:2301 [inline] batadv_tt_purge+0x4ae/0xa10 net/batman-adv/translation-table.c:3566 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 rescuer_thread+0x7b6/0x10b0 kernel/workqueue.c:3629 kthread+0x388/0x470 kernel/kthread.c:436 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245