sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=fc04/1/0x4000000000000000 softirq=56489/56490 fqs=2 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P12431/1:b..l rcu: (detected by 0, t=10506 jiffies, g=42577, q=293 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 12426 Comm: syz.1.1880 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:__raw_spin_lock_irq include/linux/spinlock_api_smp.h:119 [inline] RIP: 0010:_raw_spin_lock_irq+0x9d/0xf0 kernel/locking/spinlock.c:170 Code: 02 00 00 74 05 e8 23 07 78 f6 bf 01 00 00 00 e8 69 32 40 f6 48 8d 7b 18 31 f6 31 d2 31 c9 41 b8 01 00 00 00 45 31 c9 ff 75 08 8e 93 4d f6 48 83 c4 08 48 89 df e8 e2 37 4e f6 48 c7 04 24 0e RSP: 0018:ffffc90000a08c98 EFLAGS: 00000046 RAX: 0000000000010001 RBX: ffff8880b8727ac0 RCX: 0000000000000000 RDX: 0000000000000000 RSI: 0000000000000000 RDI: ffff8880b8727ad8 RBP: ffffc90000a08d30 R08: 0000000000000001 R09: 0000000000000000 R10: dffffc0000000000 R11: fffffbfff1f3c4ef R12: ffff888032437340 R13: dffffc0000000000 R14: 1ffff92000141194 R15: dffffc0000000000 FS: 00007f17bc46a6c0(0000) GS:ffff888125e04000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007ff22464ff98 CR3: 000000007dfa2000 CR4: 00000000003526f0 Call Trace: __run_hrtimer kernel/time/hrtimer.c:1781 [inline] __hrtimer_run_queues+0x602/0xc60 kernel/time/hrtimer.c:1841 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1903 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1041 [inline] __sysvec_apic_timer_interrupt+0x10b/0x410 arch/x86/kernel/apic/apic.c:1058 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1052 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1052 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:__sanitizer_cov_trace_pc+0x3c/0x70 kernel/kcov.c:220 Code: 8b 15 a8 64 d1 10 81 e2 00 01 ff 00 74 11 81 fa 00 01 00 00 75 35 83 b9 7c 16 00 00 00 74 2c 8b 91 58 16 00 00 83 fa 02 75 21 <48> 8b 91 60 16 00 00 48 8b 32 48 8d 7e 01 8b 89 5c 16 00 00 48 39 RSP: 0018:ffffc9000405f820 EFLAGS: 00000246 RAX: ffffffff82122996 RBX: ffffc9000405f9a0 RCX: ffff88802766dac0 RDX: 0000000000000002 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc9000405fa38 R08: 0000000000000000 R09: ffffffff821224e9 R10: ffffc9000405f96c R11: fffff5200080bf36 R12: dffffc0000000000 R13: ffff888023d0e280 R14: ffff888055908240 R15: ffffc9000405f920 pte_lockptr include/linux/mm.h:3032 [inline] pte_offset_map_rw_nolock+0x56/0x160 mm/pgtable-generic.c:328 handle_pte_fault mm/memory.c:6162 [inline] __handle_mm_fault+0xb3a/0x5400 mm/memory.c:6318 handle_mm_fault+0x40a/0x8e0 mm/memory.c:6487 faultin_page mm/gup.c:1126 [inline] __get_user_pages+0x165c/0x2a00 mm/gup.c:1428 populate_vma_page_range+0x29f/0x3a0 mm/gup.c:1860 __mm_populate+0x24c/0x380 mm/gup.c:1963 mm_populate include/linux/mm.h:3471 [inline] vm_mmap_pgoff+0x387/0x4d0 mm/util.c:586 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f17bb58eec9 Code: ff ff c3 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 48 89 f8 48 89 f7 48 89 d6 48 89 ca 4d 89 c2 4d 89 c8 4c 8b 4c 24 08 0f 05 <48> 3d 01 f0 ff ff 73 01 c3 48 c7 c1 a8 ff ff ff f7 d8 64 89 01 48 RSP: 002b:00007f17bc46a038 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f17bb7e5fa0 RCX: 00007f17bb58eec9 RDX: 0000000000000002 RSI: 0000000000b36000 RDI: 0000200000000000 RBP: 00007f17bb611f91 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f17bb7e6038 R14: 00007f17bb7e5fa0 R15: 00007ffd29480268 task:syz.5.1882 state:R running task stack:28904 pid:12431 tgid:12427 ppid:6978 task_flags:0x400140 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:7113 preempt_schedule+0xae/0xc0 kernel/sched/core.c:7137 preempt_schedule_thunk+0x16/0x30 arch/x86/entry/thunk.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0xfd/0x110 kernel/locking/spinlock.c:194 spin_unlock_irqrestore include/linux/spinlock.h:406 [inline] timerfd_clock_was_set+0x1ce/0x2c0 fs/timerfd.c:111 clock_was_set+0x73b/0x7c0 kernel/time/hrtimer.c:975 do_adjtimex+0x228/0x310 kernel/time/timekeeping.c:2753 do_clock_adjtime kernel/time/posix-timers.c:1161 [inline] __do_sys_clock_adjtime kernel/time/posix-timers.c:1173 [inline] __se_sys_clock_adjtime kernel/time/posix-timers.c:1164 [inline] __x64_sys_clock_adjtime+0x211/0x2c0 kernel/time/posix-timers.c:1164 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ff22378eec9 RSP: 002b:00007ff224650038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007ff2239e6090 RCX: 00007ff22378eec9 RDX: 0000000000000000 RSI: 0000200000000280 RDI: 0000000000000000 RBP: 00007ff223811f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007ff2239e6128 R14: 00007ff2239e6090 R15: 00007ffd54ce2fa8 rcu: rcu_preempt kthread starved for 10495 jiffies! g42577 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:27288 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 __schedule_loop kernel/sched/core.c:7011 [inline] schedule+0x165/0x360 kernel/sched/core.c:7026 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2083 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2285 kthread+0x711/0x8a0 kernel/kthread.c:463 ret_from_fork+0x4bc/0x870 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: 12420 Comm: syz-executor Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd33/0x12d0 kernel/smp.c:877 Code: 45 8b 2c 24 44 89 ee 83 e6 01 31 ff e8 b6 73 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 61 6f 0b 00 eb 38 f3 90 <42> 0f b6 04 2b 84 c0 75 11 41 f7 04 24 01 00 00 00 74 1e e8 45 6f RSP: 0018:ffffc9001bbf7540 EFLAGS: 00000202 RAX: ffffffff81b4ec2b RBX: 1ffff110170e7ffd RCX: ffff888071c23c80 RDX: 0000000000000004 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9001bbf76c0 R08: ffffffff8f9e2777 R09: 1ffffffff1f3c4ee R10: dffffc0000000000 R11: fffffbfff1f3c4ef R12: ffff8880b873ffe8 R13: dffffc0000000000 R14: ffff8880b863b240 R15: 0000000000000001 FS: 000055559109e500(0000) GS:ffff888125d04000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f7b455e5f40 CR3: 000000003cd5e000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 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+0x6b1/0x12d0 arch/x86/mm/tlb.c:1471 dup_mmap+0x1594/0x1b10 mm/mmap.c:1873 dup_mm kernel/fork.c:1489 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1541 copy_process+0x1706/0x3c00 kernel/fork.c:2181 kernel_clone+0x21e/0x840 kernel/fork.c:2609 __do_sys_clone kernel/fork.c:2750 [inline] __se_sys_clone kernel/fork.c:2734 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2734 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0xfa0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f7b45385613 Code: 1f 84 00 00 00 00 00 64 48 8b 04 25 10 00 00 00 45 31 c0 31 d2 31 f6 bf 11 00 20 01 4c 8d 90 d0 02 00 00 b8 38 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 35 89 c2 85 c0 75 2c 64 48 8b 04 25 10 00 00 RSP: 002b:00007ffc91de5e48 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f7b45385613 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 000055559109e7d0 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000