sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=3c9c/1/0x4000000000000000 softirq=273603/273605 fqs=2 rcu: (detected by 1, t=10502 jiffies, g=246721, q=302 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 25361 Comm: syz.6.9864 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:__sanitizer_cov_trace_cmp8+0x0/0x20 kernel/kcov.c:293 Code: 0c 24 89 f2 89 fe bf 04 00 00 00 e9 ea fe ff ff 66 2e 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 48 8b 0c 24 48 89 f2 48 89 fe bf 06 00 00 00 e9 b8 fe RSP: 0018:ffffc90000007d18 EFLAGS: 00000046 RAX: ffff888055257c00 RBX: ffff888055254484 RCX: ffffffff896b6992 RDX: ffff88803da94900 RSI: 0000000004000000 RDI: 0000000000000000 RBP: 0000000000000001 R08: 0000000000000004 R09: 0000000000000002 R10: 0000000000000001 R11: 0000000000000001 R12: 0000000000000000 R13: ffff888055254408 R14: 0000000004000000 R15: dffffc0000000000 FS: 00007f4bea4fc6c0(0000) GS:ffff888124a0b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2837fb CR3: 000000005ec7e000 CR4: 00000000003526f0 Call Trace: taprio_set_budgets+0x233/0x310 net/sched/sch_taprio.c:671 advance_sched+0x5f6/0xc80 net/sched/sch_taprio.c:982 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x202/0xad0 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:__sanitizer_cov_trace_const_cmp4+0x8/0x20 kernel/kcov.c:314 Code: bf 03 00 00 00 e9 58 fe ff ff 0f 1f 84 00 00 00 00 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 0c 24 <89> f2 89 fe bf 05 00 00 00 e9 2a fe ff ff 66 2e 0f 1f 84 00 00 00 RSP: 0018:ffffc9000d26fd08 EFLAGS: 00000202 RAX: 0000000000004bbd RBX: 0000000000000001 RCX: ffffffff83a7b931 RDX: 0000000000080000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffffff8bd66e20 R08: 0000000000000003 R09: 0000000000000fff R10: 0000000000000124 R11: 0000000000000001 R12: ffff88802418b780 R13: 0000000000000000 R14: ffff88805be9b080 R15: 0000000000008124 debugfs_start_creating fs/debugfs/inode.c:371 [inline] __debugfs_create_file+0x61/0x6b0 fs/debugfs/inode.c:432 debugfs_create_file_full+0x41/0x60 fs/debugfs/inode.c:469 kvm_create_vm_debugfs virt/kvm/kvm_main.c:1061 [inline] kvm_create_vm virt/kvm/kvm_main.c:1212 [inline] kvm_dev_ioctl_create_vm virt/kvm/kvm_main.c:5492 [inline] kvm_dev_ioctl+0x14ca/0x1a80 virt/kvm/kvm_main.c:5534 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:597 [inline] __se_sys_ioctl fs/ioctl.c:583 [inline] __x64_sys_ioctl+0x18e/0x210 fs/ioctl.c:583 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: 0033:0x7f4be958efc9 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:00007f4bea4fc038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007f4be97e5fa0 RCX: 00007f4be958efc9 RDX: 0000000000000000 RSI: 000000000000ae01 RDI: 0000000000000004 RBP: 00007f4be9611f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f4be97e6038 R14: 00007f4be97e5fa0 R15: 00007ffe2e0e20f8 rcu: rcu_preempt kthread starved for 10498 jiffies! g246721 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:27560 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 rcu: Stack dump where RCU GP kthread last ran: CPU: 1 UID: 0 PID: 25359 Comm: syz.3.9863 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+0xe07/0x1600 kernel/smp.c:877 Code: 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 e5 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 ff 83 e0 01 41 89 c6 89 c6 e8 RSP: 0018:ffffc9000d2af6f8 EFLAGS: 00000206 RAX: 0000000000000000 RBX: ffff8880b8442840 RCX: ffffffff81b0fd91 RDX: ffff888052d84900 RSI: ffffffff81b0fd6b RDI: 0000000000000005 RBP: 0000000000000003 R08: 0000000000000005 R09: 0000000000000000 R10: 0000000000000001 R11: 0000000000000001 R12: dffffc0000000000 R13: ffffed1017088509 R14: 0000000000000001 R15: 0000000000000000 FS: 0000000000000000(0000) GS:ffff888124b0b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f85f716ff98 CR3: 0000000031d0f000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000004501 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: 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 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:490 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline] tlb_flush_mmu mm/mmu_gather.c:403 [inline] tlb_finish_mmu+0x3c9/0x7c0 mm/mmu_gather.c:497 exit_mmap+0x3fc/0xb90 mm/mmap.c:1293 __mmput+0x12a/0x410 kernel/fork.c:1133 mmput+0x62/0x70 kernel/fork.c:1156 exit_mm kernel/exit.c:582 [inline] do_exit+0x7c7/0x2bf0 kernel/exit.c:954 do_group_exit+0xd3/0x2a0 kernel/exit.c:1107 get_signal+0x2671/0x26d0 kernel/signal.c:3034 arch_do_signal_or_restart+0x8f/0x7c0 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop+0x85/0x130 kernel/entry/common.c:40 exit_to_user_mode_prepare include/linux/irq-entry-common.h:225 [inline] syscall_exit_to_user_mode_work include/linux/entry-common.h:175 [inline] syscall_exit_to_user_mode include/linux/entry-common.h:210 [inline] do_syscall_64+0x426/0xfa0 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f85f638efc9 Code: Unable to access opcode bytes at 0x7f85f638ef9f. RSP: 002b:00007f85f71700e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f85f65e5fa8 RCX: 00007f85f638efc9 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f85f65e5fa8 RBP: 00007f85f65e5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f85f65e6038 R14: 00007ffe5e7e2f50 R15: 00007ffe5e7e3038