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): P13912/1:b..l P5201/1:b..l rcu: (detected by 0, t=10502 jiffies, g=58661, q=3009 ncpus=2) task:udevd state:R running task stack:23760 pid:5201 tgid:5201 ppid:1 task_flags:0x400140 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6944 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6968 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 unwind_next_frame+0x18f8/0x22d0 arch/x86/kernel/unwind_orc.c:672 __unwind_start+0x59a/0x740 arch/x86/kernel/unwind_orc.c:760 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe5/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 discard_slab mm/slub.c:2684 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3153 put_cpu_partial+0x17c/0x250 mm/slub.c:3228 __slab_free+0x290/0x380 mm/slub.c:4479 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x23/0xb0 mm/kasan/common.c:385 kasan_kmalloc include/linux/kasan.h:260 [inline] __do_kmalloc_node mm/slub.c:4294 [inline] __kmalloc_noprof+0x285/0x4c0 mm/slub.c:4306 kmalloc_noprof include/linux/slab.h:905 [inline] kzalloc_noprof include/linux/slab.h:1037 [inline] tomoyo_encode2 security/tomoyo/realpath.c:45 [inline] tomoyo_encode+0x26f/0x540 security/tomoyo/realpath.c:80 tomoyo_realpath_from_path+0x59e/0x5e0 security/tomoyo/realpath.c:283 tomoyo_get_realpath security/tomoyo/file.c:151 [inline] tomoyo_path_perm+0x2c0/0x610 security/tomoyo/file.c:822 security_inode_getattr+0x130/0x330 security/security.c:2377 vfs_getattr fs/stat.c:243 [inline] vfs_statx_path+0x23/0x2b0 fs/stat.c:283 vfs_statx+0x135/0x1f0 fs/stat.c:349 vfs_fstatat+0xda/0x150 fs/stat.c:368 __do_sys_newfstatat fs/stat.c:532 [inline] __se_sys_newfstatat fs/stat.c:526 [inline] __x64_sys_newfstatat+0x11d/0x1a0 fs/stat.c:526 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f301ef735f4 RSP: 002b:00007ffef99d7558 EFLAGS: 00000246 ORIG_RAX: 0000000000000106 RAX: ffffffffffffffda RBX: 000055f6334186e0 RCX: 00007f301ef735f4 RDX: 00007ffef99d7568 RSI: 000055f633408897 RDI: 00000000ffffff9c RBP: 000055f645ebd448 R08: 00062305ed946d00 R09: 7fffffffffffffff R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00062305ed946d00 R15: 000055f63340cdca task:syz-executor state:R running task stack:19344 pid:13912 tgid:13912 ppid:13881 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7087 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:__unwind_start+0x5a4/0x740 Code: 74 08 48 89 df e8 4c b6 bb 00 48 8b 44 24 10 48 39 03 0f 87 3b fb ff ff 4c 89 f7 e8 76 d2 ff ff 48 ba 00 00 00 00 00 fc ff df <48> 8b 04 24 0f b6 04 10 84 c0 75 0f 41 83 3e 00 0f 85 5d ff ff ff RSP: 0018:ffffc90012217280 EFLAGS: 00000286 RAX: 0000000080000001 RBX: ffffc90012217318 RCX: 0000000080000000 RDX: dffffc0000000000 RSI: ffffc90012210000 RDI: 0000000000000001 RBP: 1ffff92002442e5d R08: ffffc90012217370 R09: ffffc90012217330 R10: dffffc0000000000 R11: fffff52002442e68 R12: 1ffff92002442e5e R13: ffffc900122172f0 R14: ffffc900122172e0 R15: ffffc900122172e8 unwind_start arch/x86/include/asm/unwind.h:64 [inline] arch_stack_walk+0xe5/0x150 arch/x86/kernel/stacktrace.c:24 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1127 [inline] free_frozen_pages+0xe0d/0x10e0 mm/page_alloc.c:2660 discard_slab mm/slub.c:2684 [inline] __put_partials+0x160/0x1c0 mm/slub.c:3153 put_cpu_partial+0x17c/0x250 mm/slub.c:3228 __slab_free+0x290/0x380 mm/slub.c:4479 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4115 [inline] slab_alloc_node mm/slub.c:4164 [inline] __do_kmalloc_node mm/slub.c:4293 [inline] __kmalloc_node_noprof+0x23c/0x4d0 mm/slub.c:4300 __kvmalloc_node_noprof+0x72/0x190 mm/util.c:662 kvmalloc_array_node_noprof include/linux/slab.h:1063 [inline] alloc_fdtable+0xdf/0x2a0 fs/file.c:199 dup_fd+0x869/0xb40 fs/file.c:400 copy_files+0xc8/0x120 kernel/fork.c:1806 copy_process+0x1672/0x3cf0 kernel/fork.c:2391 kernel_clone+0x226/0x8e0 kernel/fork.c:2815 __do_sys_clone kernel/fork.c:2958 [inline] __se_sys_clone kernel/fork.c:2942 [inline] __x64_sys_clone+0x267/0x2e0 kernel/fork.c:2942 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f570fd839d3 RSP: 002b:00007ffd2aaa5fb8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f570fd839d3 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 000055555ee817d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 00000000000fafdd R15: 00007ffd2aaa6150 rcu: rcu_preempt kthread starved for 8242 jiffies! g58661 f0x0 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:25784 pid:17 tgid:17 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5378 [inline] __schedule+0x190e/0x4c90 kernel/sched/core.c:6765 __schedule_loop kernel/sched/core.c:6842 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6857 schedule_timeout+0x15a/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2024 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2226 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 11350 Comm: kworker/u8:26 Not tainted 6.14.0-rc3-syzkaller-00295-g27102b38b8ca #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 Workqueue: writeback wb_workfn (flush-8:0) RIP: 0010:check_preemption_disabled+0x14/0x120 lib/smp_processor_id.c:13 Code: 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 57 41 56 41 54 53 48 83 ec 10 65 48 8b 04 25 28 00 00 00 <48> 89 44 24 08 65 8b 1d 0c 6b fb 73 65 8b 05 01 6b fb 73 a9 ff ff RSP: 0018:ffffc90000a17dc8 EFLAGS: 00000282 RAX: 3cbcacb2a3009c00 RBX: 0000000000000001 RCX: ffff88803360bc00 RDX: ffff88803360bc00 RSI: ffffffff8c80eee0 RDI: ffffffff8c80eea0 RBP: ffffc90000a17f30 R08: ffffffff8a5b8f83 R09: 1ffffffff28a9308 R10: dffffc0000000000 R11: fffffbfff28a9309 R12: 1ffff92000142fcc R13: ffff888035375ac0 R14: ffff88807a425dc0 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f9429e8cdb3 CR3: 000000007d652000 CR4: 0000000000350ef0 Call Trace: rcu_is_watching_curr_cpu include/linux/context_tracking.h:128 [inline] rcu_is_watching+0x15/0xb0 kernel/rcu/tree.c:716 rcu_read_lock include/linux/rcupdate.h:850 [inline] nf_hook+0xdc/0x450 include/linux/netfilter.h:238 NF_HOOK_COND include/linux/netfilter.h:302 [inline] ip_output+0x185/0x230 net/ipv4/ip_output.c:434 synproxy_send_client_synack+0x8a4/0xe20 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x3ca/0x610 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x362/0xa60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4af/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc5/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a6/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5899 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:6012 process_backlog+0x662/0x15b0 net/core/dev.c:6360 __napi_poll+0xcd/0x490 net/core/dev.c:7194 napi_poll net/core/dev.c:7263 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:7385 handle_softirqs+0x2d6/0x9b0 kernel/softirq.c:561 __do_softirq kernel/softirq.c:595 [inline] invoke_softirq kernel/softirq.c:435 [inline] __irq_exit_rcu+0xf7/0x220 kernel/softirq.c:662 irq_exit_rcu+0x9/0x30 kernel/softirq.c:678 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa6/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1bae/0x2d30 kernel/smp.c:885 Code: 89 e6 83 e6 01 31 ff e8 30 f5 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 e0 f0 0b 00 eb 41 f3 90 48 b8 00 00 00 00 00 fc ff df <0f> b6 04 03 84 c0 75 11 41 f7 45 00 01 00 00 00 74 1e e8 bb f0 0b RSP: 0018:ffffc900033b5f20 EFLAGS: 00000293 RAX: dffffc0000000000 RBX: 1ffff110170c8c99 RCX: ffff88803360bc00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc900033b6120 R08: ffffffff81b5cd10 R09: 1ffffffff2079d8e R10: dffffc0000000000 R11: ffffffff816a90d0 R12: ffff8880b873fb48 R13: ffff8880b86464c8 R14: ffff8880b873fb40 R15: 0000000000000000 on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1052 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:966 [inline] flush_tlb_mm_range+0x42d/0x710 arch/x86/mm/tlb.c:1054 flush_tlb_page arch/x86/include/asm/tlbflush.h:255 [inline] ptep_clear_flush+0x11a/0x170 mm/pgtable-generic.c:101 page_vma_mkclean_one+0x58a/0x9a0 mm/rmap.c:1051 page_mkclean_one+0x272/0x350 mm/rmap.c:1092 rmap_walk_file+0x504/0x780 mm/rmap.c:2708 rmap_walk mm/rmap.c:2726 [inline] folio_mkclean+0x252/0x370 mm/rmap.c:1124 folio_clear_dirty_for_io+0x219/0x950 mm/page-writeback.c:3018 mpage_submit_folio+0x84/0x340 fs/ext4/inode.c:1913 mpage_process_page_bufs+0x6d1/0x9d0 fs/ext4/inode.c:2045 mpage_prepare_extent_to_map+0xecb/0x1860 fs/ext4/inode.c:2546 ext4_do_writepages+0xc2a/0x3df0 fs/ext4/inode.c:2688 ext4_writepages+0x213/0x3c0 fs/ext4/inode.c:2824 do_writepages+0x361/0x880 mm/page-writeback.c:2687 __writeback_single_inode+0x14f/0x10d0 fs/fs-writeback.c:1680 writeback_sb_inodes+0x820/0x1360 fs/fs-writeback.c:1976 __writeback_inodes_wb+0x11b/0x260 fs/fs-writeback.c:2047 wb_writeback+0x427/0xb80 fs/fs-writeback.c:2158 wb_check_old_data_flush fs/fs-writeback.c:2262 [inline] wb_do_writeback fs/fs-writeback.c:2315 [inline] wb_workfn+0xb94/0x1080 fs/fs-writeback.c:2343 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xac0/0x18e0 kernel/workqueue.c:3317 worker_thread+0x870/0xd30 kernel/workqueue.c:3398 kthread+0x7ab/0x920 kernel/kthread.c:464 ret_from_fork+0x4d/0x80 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244