sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (2 ticks this GP) idle=955c/1/0x4000000000000000 softirq=17036/17036 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5479/1:b.el P5854/1:b..l rcu: (detected by 1, t=10622 jiffies, g=10585, q=655 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5852 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:find_held_lock+0x7/0x80 kernel/locking/lockdep.c:5343 Code: ee 02 00 eb 9e e8 89 6f c8 09 66 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 41 56 41 89 d6 41 55 <49> 89 cd 41 54 49 89 f4 55 8d 6a ff 48 63 c5 53 48 8d 04 80 48 8d RSP: 0000:ffffc90000007cd8 EFLAGS: 00000006 RAX: 0000000000000000 RBX: ffffffff9acfaf50 RCX: ffffc90000007cfc RDX: 0000000000000005 RSI: ffffffff9acfaf50 RDI: ffff888025622480 RBP: 0000000000000006 R08: 0000000000000001 R09: fffff52000000f98 R10: 0000000000000003 R11: 0000000000000001 R12: ffffffff84aca25c R13: 0000000000000006 R14: 0000000000000005 R15: 0000000000000005 FS: 00007f303f18e880(0000) GS:ffff888124a05000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055d4c79b9fe8 CR3: 000000007ebdc000 CR4: 00000000003526f0 Call Trace: __lock_release kernel/locking/lockdep.c:5535 [inline] lock_release+0xe4/0x2f0 kernel/locking/lockdep.c:5889 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:149 [inline] _raw_spin_unlock_irqrestore+0x1a/0x80 kernel/locking/spinlock.c:194 debug_object_deactivate+0x1ec/0x3a0 lib/debugobjects.c:888 debug_hrtimer_deactivate kernel/time/hrtimer.c:443 [inline] debug_deactivate kernel/time/hrtimer.c:483 [inline] __run_hrtimer kernel/time/hrtimer.c:1745 [inline] __hrtimer_run_queues+0x46f/0xad0 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x397/0x8e0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x3f0 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0x9f/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xdfd/0x1600 kernel/smp.c:877 Code: 57 48 8b 54 24 10 4c 89 74 24 10 49 89 d5 48 89 d5 48 89 54 24 18 49 c1 ed 03 83 e5 07 4d 01 e5 83 c5 03 e8 b5 0c 0c 00 f3 90 <41> 0f b6 45 00 40 38 c5 7c 08 84 c0 0f 85 e0 05 00 00 8b 43 08 31 RSP: 0000:ffffc90004387898 EFLAGS: 00000293 RAX: 0000000000000000 RBX: ffff8880b8540320 RCX: ffffffff81b0db41 RDX: ffff888025622480 RSI: ffffffff81b0db1b RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 R13: ffffed10170a8065 R14: 0000000000000001 R15: 0000000000000001 on_each_cpu_cond_mask+0x40/0x90 kernel/smp.c:1043 __flush_tlb_multi arch/x86/include/asm/paravirt.h:91 [inline] flush_tlb_multi arch/x86/mm/tlb.c:1381 [inline] flush_tlb_mm_range+0x4a0/0x17a0 arch/x86/mm/tlb.c:1471 flush_tlb_page arch/x86/include/asm/tlbflush.h:324 [inline] ptep_clear_flush+0x136/0x180 mm/pgtable-generic.c:101 wp_page_copy mm/memory.c:3746 [inline] do_wp_page+0x1774/0x52b0 mm/memory.c:4141 handle_pte_fault mm/memory.c:6211 [inline] __handle_mm_fault+0x1ae3/0x2aa0 mm/memory.c:6336 handle_mm_fault+0x589/0xd10 mm/memory.c:6505 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f303eab5db7 Code: 00 00 00 41 55 48 89 d0 49 89 fd 41 54 49 89 f4 53 4c 89 c3 48 83 ec 10 48 39 4f 60 0f 84 c1 00 00 00 42 f6 44 01 08 01 74 59 <48> 83 61 08 fe 48 3d ff 03 00 00 76 69 49 8b 55 70 49 8d 75 60 48 RSP: 002b:00007fff1d56a580 EFLAGS: 00010202 RAX: 0000000000006010 RBX: 00000000000001f0 RCX: 000055d4c79b9fe0 RDX: 0000000000006010 RSI: 000055d4c79b3fd0 RDI: 00007f303ebf1ac0 RBP: 00007f303ebf1ac0 R08: 00000000000001f0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055d4c79b3fd0 R13: 00007f303ebf1ac0 R14: 00000000000001f0 R15: 00007f303ebf1ac0 task:udevd state:R running task stack:26808 pid:5854 tgid:5854 ppid:5184 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:7113 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock include/linux/spinlock_api_smp.h:143 [inline] _raw_spin_unlock+0x3e/0x50 kernel/locking/spinlock.c:186 spin_unlock include/linux/spinlock.h:391 [inline] wp_page_copy mm/memory.c:3781 [inline] do_wp_page+0x186d/0x52b0 mm/memory.c:4141 handle_pte_fault mm/memory.c:6211 [inline] __handle_mm_fault+0x1ae3/0x2aa0 mm/memory.c:6336 handle_mm_fault+0x589/0xd10 mm/memory.c:6505 do_user_addr_fault+0x60c/0x1370 arch/x86/mm/fault.c:1336 handle_page_fault arch/x86/mm/fault.c:1476 [inline] exc_page_fault+0x64/0xc0 arch/x86/mm/fault.c:1532 asm_exc_page_fault+0x26/0x30 arch/x86/include/asm/idtentry.h:618 RIP: 0033:0x7f303eab5db7 RSP: 002b:00007fff1d56a580 EFLAGS: 00010202 RAX: 0000000000006010 RBX: 00000000000001f0 RCX: 000055d4c79b9fe0 RDX: 0000000000006010 RSI: 000055d4c79b3fd0 RDI: 00007f303ebf1ac0 RBP: 00007f303ebf1ac0 R08: 00000000000001f0 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 000055d4c79b3fd0 R13: 00007f303ebf1ac0 R14: 00000000000001f0 R15: 00007f303ebf1ac0 task:dhcpcd state:R running task stack:22616 pid:5479 tgid:5479 ppid:5478 task_flags:0x400140 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7256 irqentry_exit+0x36/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__orc_find+0x8e/0xf0 arch/x86/kernel/unwind_orc.c:106 Code: 00 48 89 da 48 c1 ea 03 0f b6 34 0a 48 89 da 83 e2 07 83 c2 03 40 38 f2 7c 05 40 84 f6 75 4b 48 63 13 48 01 da 49 39 d5 73 af <4c> 8d 63 fc 49 39 ec 73 b2 4d 29 f7 49 c1 ff 02 4b 8d 14 7f 48 8d RSP: 0018:ffffc90003357218 EFLAGS: 00000287 RAX: ffffffff910f754a RBX: ffffffff908ea524 RCX: dffffc0000000000 RDX: ffffffff81000154 RSI: 0000000000000000 RDI: ffffffff908ea520 RBP: ffffffff908ea520 R08: ffffffff910f7616 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000001 R12: ffffffff908ea528 R13: ffffffff8100012f R14: ffffffff908ea520 R15: ffffffff908ea520 orc_find arch/x86/kernel/unwind_orc.c:227 [inline] unwind_next_frame+0x2ec/0x20a0 arch/x86/kernel/unwind_orc.c:494 arch_stack_walk+0x94/0x100 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x8e/0xc0 kernel/stacktrace.c:122 kasan_save_stack+0x33/0x60 mm/kasan/common.c:56 kasan_save_track+0x14/0x30 mm/kasan/common.c:77 poison_kmalloc_redzone mm/kasan/common.c:400 [inline] __kasan_kmalloc+0xaa/0xb0 mm/kasan/common.c:417 kasan_kmalloc include/linux/kasan.h:262 [inline] __do_kmalloc_node mm/slub.c:5650 [inline] __kmalloc_node_noprof+0x347/0x8a0 mm/slub.c:5656 kmalloc_array_node_noprof include/linux/slab.h:1075 [inline] alloc_slab_obj_exts+0x43/0xf0 mm/slub.c:2127 account_slab mm/slub.c:3186 [inline] allocate_slab mm/slub.c:3251 [inline] new_slab+0x283/0x360 mm/slub.c:3286 ___slab_alloc+0xd79/0x1a50 mm/slub.c:4655 __slab_alloc.constprop.0+0x63/0x110 mm/slub.c:4778 __slab_alloc_node mm/slub.c:4854 [inline] slab_alloc_node mm/slub.c:5276 [inline] kmem_cache_alloc_noprof+0x43f/0x6e0 mm/slub.c:5295 anon_vma_chain_alloc mm/rmap.c:141 [inline] anon_vma_clone+0xd8/0x5c0 mm/rmap.c:287 anon_vma_fork+0x7a/0x620 mm/rmap.c:350 dup_mmap+0x151f/0x2280 mm/mmap.c:1797 dup_mm kernel/fork.c:1489 [inline] copy_mm kernel/fork.c:1541 [inline] copy_process+0x3f0c/0x76a0 kernel/fork.c:2181 kernel_clone+0xfc/0x930 kernel/fork.c:2609 __do_sys_clone+0xce/0x120 kernel/fork.c:2750 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xcd/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3d3f4ca636 RSP: 002b:00007ffc149763b0 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 00007ffc149763b8 RCX: 00007f3d3f4ca636 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 00007ffc14996900 R08: 0000000000000000 R09: 0000000000000001 R10: 00007f3d3f3f6a10 R11: 0000000000000246 R12: 00007ffc149764f0 R13: 0000000000000000 R14: 0000000000000000 R15: 000055fa2f52dac0 rcu: rcu_preempt kthread timer wakeup didn't happen for 10621 jiffies! g10585 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=13721 rcu: rcu_preempt kthread starved for 10622 jiffies! g10585 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 ->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:I stack:28552 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1190/0x5de0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0xe7/0x3a0 kernel/sched/core.c:7026 schedule_timeout+0x123/0x290 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x1ea/0xaf0 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x26d/0x380 kernel/rcu/tree.c:2285 kthread+0x3c5/0x780 kernel/kthread.c:463 ret_from_fork+0x675/0x7d0 arch/x86/kernel/process.c:158 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245