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): P5280/1:b..l P24829/1:b..l P5994/1:b..l P4975/1:b..l P1351/1:b..l P18851/2:b..l rcu: (detected by 0, t=10502 jiffies, g=154165, q=1268 ncpus=1) task:syz-executor state:R running task stack:22312 pid:18851 tgid:18851 ppid:18840 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_common+0x82/0xd0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __mod_memcg_lruvec_state+0x20f/0x360 mm/memcontrol.c:934 mod_memcg_lruvec_state+0x1e7/0x270 mm/memcontrol.c:950 mod_lruvec_state mm/memcontrol.c:973 [inline] lruvec_stat_mod_folio+0x239/0x3e0 mm/memcontrol.c:993 lruvec_stat_add_folio include/linux/vmstat.h:556 [inline] __pagetable_ctor include/linux/mm.h:3803 [inline] pagetable_pte_ctor include/linux/mm.h:3826 [inline] __pte_alloc_one_noprof include/asm-generic/pgalloc.h:79 [inline] pte_alloc_one+0x1e0/0x370 arch/x86/mm/pgtable.c:18 __pte_alloc+0x25/0x1a0 mm/memory.c:453 copy_pte_range mm/memory.c:1253 [inline] copy_pmd_range+0x5029/0x5880 mm/memory.c:1408 copy_pud_range mm/memory.c:1445 [inline] copy_p4d_range mm/memory.c:1469 [inline] copy_page_range+0xc26/0x1250 mm/memory.c:1555 dup_mmap+0xf21/0x1d90 mm/mmap.c:1840 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: 0033:0x7f6ab09c6a92 RSP: 002b:00007ffe6ea6d430 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffe6ea6d430 RCX: 00007f6ab09c6a92 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffe6ea6d5bc R08: 0000000000000000 R09: 0000000000000001 R10: 00005555922db7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 00000000000927c0 R14: 00000000000bed99 R15: 00007ffe6ea6d610 task:kworker/u8:8 state:R running task stack:20416 pid:1351 tgid:1351 ppid:2 task_flags:0x24248060 flags:0x00080000 Workqueue: writeback wb_workfn (flush-8:0) Call Trace: context_switch kernel/sched/core.c:5510 [inline] __schedule+0x17d9/0x56c0 kernel/sched/core.c:7234 preempt_schedule_notrace+0x57/0x90 kernel/sched/core.c:7506 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:753 trace_lock_acquire include/trace/events/lock.h:23 [inline] lock_acquire+0x5f/0x350 kernel/locking/lockdep.c:5831 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] percpu_ref_put_many+0x3d/0x240 include/linux/percpu-refcount.h:330 percpu_ref_put include/linux/percpu-refcount.h:351 [inline] blk_mq_dispatch_list+0xd31/0xe10 block/blk-mq.c:2922 blk_mq_flush_plug_list+0x45f/0x540 block/blk-mq.c:2966 __blk_flush_plug+0x3ed/0x4d0 block/blk-core.c:1266 blk_flush_plug include/linux/blkdev.h:1222 [inline] io_schedule_prepare kernel/sched/core.c:8123 [inline] io_schedule+0x77/0xd0 kernel/sched/core.c:8153 rq_qos_wait+0x266/0x360 block/blk-rq-qos.c:307 __wbt_wait block/blk-wbt.c:598 [inline] wbt_wait+0x326/0x550 block/blk-wbt.c:658 __rq_qos_throttle+0x6b/0xb0 block/blk-rq-qos.c:66 rq_qos_throttle block/blk-rq-qos.h:164 [inline] blk_mq_get_new_requests block/blk-mq.c:3032 [inline] blk_mq_submit_bio+0x1522/0x2a40 block/blk-mq.c:3170 __submit_bio_noacct_mq block/blk-core.c:756 [inline] submit_bio_noacct_nocheck+0x2f4/0xa40 block/blk-core.c:790 blk_crypto_submit_bio include/linux/blk-crypto.h:203 [inline] ext4_io_submit+0x11b/0x190 fs/ext4/page-io.c:404 ext4_do_writepages+0xc50/0x47a0 fs/ext4/inode.c:2899 ext4_writepages+0x241/0x3b0 fs/ext4/inode.c:3043 do_writepages+0x338/0x560 mm/page-writeback.c:2571 __writeback_single_inode+0x12e/0xf90 fs/fs-writeback.c:1787 writeback_sb_inodes+0x9de/0x1b00 fs/fs-writeback.c:2079 __writeback_inodes_wb+0x114/0x240 fs/fs-writeback.c:2155 wb_writeback+0x42f/0xad0 fs/fs-writeback.c:2266 wb_check_old_data_flush fs/fs-writeback.c:2370 [inline] wb_do_writeback fs/fs-writeback.c:2449 [inline] wb_workfn+0xc92/0x10f0 fs/fs-writeback.c:2477 process_one_work kernel/workqueue.c:3322 [inline] process_scheduled_works+0xa8e/0x14e0 kernel/workqueue.c:3405 worker_thread+0xa47/0xfb0 kernel/workqueue.c:3486 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 task:klogd state:R running task stack:23400 pid:4975 tgid:4975 ppid:1 task_flags:0x400100 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_irqrestore include/linux/spinlock_api_smp.h:179 [inline] _raw_spin_unlock_irqrestore+0x74/0x80 kernel/locking/spinlock.c:198 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] __wake_up_common_lock+0x195/0x1f0 kernel/sched/wait.c:127 sock_def_readable+0x1eb/0x550 net/core/sock.c:3659 unix_dgram_sendmsg+0xd30/0x17b0 net/unix/af_unix.c:2293 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] __sys_sendto+0x408/0x5a0 net/socket.c:2252 __do_sys_sendto net/socket.c:2259 [inline] __se_sys_sendto net/socket.c:2255 [inline] __x64_sys_sendto+0xde/0x100 net/socket.c:2255 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: 0033:0x7fc84e29d407 RSP: 002b:00007ffd6fd6ace0 EFLAGS: 00000202 ORIG_RAX: 000000000000002c RAX: ffffffffffffffda RBX: 00007fc84e14dc80 RCX: 00007fc84e29d407 RDX: 000000000000005f RSI: 00007ffd6fd6ae20 RDI: 0000000000000003 RBP: 00007ffd6fd6b250 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000004000 R11: 0000000000000202 R12: 00007ffd6fd6b268 R13: 00007ffd6fd6ae20 R14: 0000000000000044 R15: 00007ffd6fd6ae20 task:udevd state:R running task stack:23312 pid:5994 tgid:5994 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:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5872 Code: ff ff ff e8 f1 6c 2e 0a f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 db 87 ca 11 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d e9 ab 78 6d ff cc 48 8d 3d c8 63 b8 RSP: 0018:ffffc90005427510 EFLAGS: 00000282 RAX: 99f8450eda959f00 RBX: 0000000000000000 RCX: 0000000000000046 RDX: 00000000955aa379 RSI: ffffffff8e4b420d RDI: ffffffff8c4bdd80 RBP: ffffffff823e99ae R08: ffffffff823e99ae R09: 0000000000000000 R10: 0000000000000000 R11: ffffffff8eb59c60 R12: 0000000000000002 R13: ffffffff8eb59c60 R14: 0000000000000000 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:300 [inline] rcu_read_lock include/linux/rcupdate.h:840 [inline] __update_page_owner_free_handle+0x4b/0x4a0 mm/page_owner.c:283 __reset_page_owner+0x85/0x1f0 mm/page_owner.c:321 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_lru_noprof+0x2aa/0x5f0 mm/slub.c:4950 __d_alloc+0x37/0x6f0 fs/dcache.c:1902 d_alloc_parallel+0xde/0x16a0 fs/dcache.c:2761 lookup_open fs/namei.c:4423 [inline] open_last_lookups fs/namei.c:4608 [inline] path_openat+0xbea/0x3830 fs/namei.c:4860 do_file_open+0x23e/0x4a0 fs/namei.c:4892 do_sys_openat2+0x115/0x200 fs/open.c:1368 do_sys_open fs/open.c:1374 [inline] __do_sys_openat fs/open.c:1390 [inline] __se_sys_openat fs/open.c:1385 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1385 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: 0033:0x7f0eed9cf407 RSP: 002b:00007ffdad4d84a0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f0eed943880 RCX: 00007f0eed9cf407 RDX: 0000000000080241 RSI: 00007ffdad4d8a00 RDI: ffffffffffffff9c RBP: 0000000000000004 R08: 0000000000000000 R09: 0000000000000000 R10: 00000000000001b6 R11: 0000000000000202 R12: 000056082f8ccdfc R13: 000056082f8ccdfc R14: 0000000000000001 R15: 000056082f8e7140 task:syz.3.6732 state:R running task stack:25256 pid:24829 tgid:24828 ppid:5639 task_flags:0x40044c flags:0x00080002 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: 0033:0x7f9891b9e019 RSP: 002b:00007f9892a71028 EFLAGS: 00000246 ORIG_RAX: 000000000000002c RAX: fffffffffffffe00 RBX: 00007f9891e25fa0 RCX: 00007f9891b9e019 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000000000004 RBP: 00007f9891c3500c R08: 0000200000000000 R09: 0000000000000010 R10: 0000000020000010 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f9891e26038 R14: 00007f9891e25fa0 R15: 00007ffd5452a858 task:dhcpcd state:R running task stack:24624 pid:5280 tgid:5280 ppid:1 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_common+0x82/0xd0 kernel/sched/core.c:7413 preempt_schedule_thunk+0x16/0x40 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:179 [inline] _raw_spin_unlock_irqrestore+0x74/0x80 kernel/locking/spinlock.c:198 spin_unlock_irqrestore include/linux/spinlock.h:408 [inline] __wake_up_common_lock+0x195/0x1f0 kernel/sched/wait.c:127 sock_def_readable+0x1eb/0x550 net/core/sock.c:3659 unix_dgram_sendmsg+0xd30/0x17b0 net/unix/af_unix.c:2293 sock_sendmsg_nosec+0x13a/0x180 net/socket.c:775 __sock_sendmsg net/socket.c:790 [inline] sock_write_iter+0x2de/0x3e0 net/socket.c:1241 do_iter_readv_writev+0x612/0x8c0 fs/read_write.c:-1 vfs_writev+0x343/0x990 fs/read_write.c:1058 do_writev+0x154/0x2e0 fs/read_write.c:1104 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: 0033:0x7fa16a621407 RSP: 002b:00007ffe3ebecb10 EFLAGS: 00000202 ORIG_RAX: 0000000000000014 RAX: ffffffffffffffda RBX: 00007fa16a597780 RCX: 00007fa16a621407 RDX: 0000000000000005 RSI: 00007ffe3ebecb70 RDI: 000000000000000a RBP: 0000560401e780b0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 0000560401e780b0 R13: 000000000000012c R14: 00000000ffffffff R15: 0000000000000000 rcu: rcu_preempt kthread starved for 373 jiffies! g154165 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: 3223 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:skb_clone+0x223/0x3a0 net/core/skbuff.c:2120 Code: c7 d0 4c 86 8e e8 8d 7f 99 f8 48 8b 3d c6 20 eb 04 44 89 f6 e8 8e 8b 8d f8 48 85 c0 74 31 49 89 c6 e8 51 e6 2b f8 4d 8d 7e 7e <4c> 89 f8 48 c1 e8 03 42 0f b6 04 20 84 c0 0f 85 09 01 00 00 41 80 RSP: 0018:ffffc90000006e28 EFLAGS: 00000246 RAX: ffffffff899b2c1f RBX: ffff888159933140 RCX: ffff888032f51f00 RDX: 0000000000000100 RSI: ffffffff8c4bdd60 RDI: ffffffff8c4bdd20 RBP: ffff8881599331be R08: 00000000ffffffff R09: ffff888159933000 R10: 000000000000001d R11: ffffffff8eb59c60 R12: dffffc0000000000 R13: 0000000000000820 R14: ffff888159933000 R15: ffff88815993307e FS: 0000000000000000(0000) GS:ffff888124f4b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f0d664c7ae0 CR3: 000000004a950000 CR4: 0000000000350ef0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000600 Call Trace: netem_enqueue+0xecb/0x32b0 net/sched/sch_netem.c:507 dev_qdisc_enqueue+0x4e/0x260 net/core/dev.c:4179 __dev_xmit_skb net/core/dev.c:4294 [inline] __dev_queue_xmit+0x1b45/0x3820 net/core/dev.c:4836 dev_queue_xmit include/linux/netdevice.h:3446 [inline] neigh_hh_output include/net/neighbour.h:544 [inline] neigh_output include/net/neighbour.h:558 [inline] ip_finish_output2+0xbda/0x10b0 net/ipv4/ip_output.c:236 NF_HOOK_COND include/linux/netfilter.h:307 [inline] ip_output+0x29f/0x450 net/ipv4/ip_output.c:437 synproxy_send_client_synack+0x89b/0xde0 net/netfilter/nf_synproxy_core.c:487 nft_synproxy_eval_v4+0x362/0x4e0 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x335/0x550 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:237 [inline] nft_do_chain+0x48d/0x1b10 net/netfilter/nf_tables_core.c:285 nft_do_chain_inet+0x360/0x4b0 net/netfilter/nft_chain_filter.c:162 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 NF_HOOK+0x336/0x3c0 include/linux/netfilter.h:318 __netif_receive_skb_one_core net/core/dev.c:6212 [inline] __netif_receive_skb net/core/dev.c:6325 [inline] process_backlog+0xa34/0x1860 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_req_purge net/batman-adv/translation-table.c:2642 [inline] batadv_tt_purge+0x758/0xa10 net/batman-adv/translation-table.c:3567 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