sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=cabc/1/0x4000000000000000 softirq=152725/152725 fqs=0 rcu: (detected by 0, t=10505 jiffies, g=169761, q=699 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 22788 Comm: syz.3.4447 Not tainted 6.15.0-rc2-syzkaller-00471-g119009db2674 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:check_kcov_mode kernel/kcov.c:183 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x20/0x70 kernel/kcov.c:217 Code: 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 65 48 8b 0c 25 08 60 68 93 65 8b 15 f8 a2 a5 11 81 e2 00 01 ff 00 74 11 <81> fa 00 01 00 00 75 35 83 b9 3c 16 00 00 00 74 2c 8b 91 18 16 00 RSP: 0018:ffffc90000a08d38 EFLAGS: 00000006 RAX: ffffffff81b00e4c RBX: ffff888027161368 RCX: ffff888032c70000 RDX: 0000000000010000 RSI: 0000000000000004 RDI: 0000000000000001 RBP: ffffc90000a08ea0 R08: ffff8880b87276c3 R09: 1ffff110170e4ed8 R10: dffffc0000000000 R11: ffffed10170e4ed9 R12: 1ffff110170e4ef3 R13: ffffffff8a25e0d0 R14: ffff888027161340 R15: ffff8880b87276c0 FS: 0000000000000000(0000) GS:ffff88812509a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f08d734bf98 CR3: 0000000012bc6000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 00000000ffff000b DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: arch_static_branch arch/x86/include/asm/jump_label.h:36 [inline] trace_hrtimer_expire_entry include/trace/events/timer.h:259 [inline] __run_hrtimer kernel/time/hrtimer.c:1758 [inline] __hrtimer_run_queues+0x48c/0xd40 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x403/0xa40 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1038 [inline] __sysvec_apic_timer_interrupt+0x110/0x420 arch/x86/kernel/apic/apic.c:1055 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1049 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1049 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x167/0x2f0 arch/x86/include/asm/irqflags.h:-1 Code: c7 44 24 10 00 00 00 00 9c 8f 44 24 10 f7 44 24 10 00 02 00 00 0f 85 fd 00 00 00 41 f7 c6 00 02 00 00 74 01 fb 65 48 8b 45 00 <48> 3b 44 24 38 0f 85 72 01 00 00 48 83 c4 40 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9000d08f110 EFLAGS: 00000206 RAX: df0b4331700db100 RBX: ffffffff8ed3dea0 RCX: df0b4331700db100 RDX: 0000000000000000 RSI: ffffffff8e4db41e RDI: ffffffff8ca1b5c0 RBP: ffffffff93686020 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000002 R14: 0000000000000246 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock_sched include/linux/rcupdate.h:932 [inline] pfn_valid+0x113/0x450 include/linux/mmzone.h:2116 page_table_check_clear+0x21/0x6f0 mm/page_table_check.c:70 ptep_get_and_clear_full arch/x86/include/asm/jump_label.h:-1 [inline] get_and_clear_full_ptes include/linux/pgtable.h:714 [inline] zap_present_folio_ptes mm/memory.c:1501 [inline] zap_present_ptes mm/memory.c:1586 [inline] do_zap_pte_range mm/memory.c:1687 [inline] zap_pte_range mm/memory.c:1731 [inline] zap_pmd_range mm/memory.c:1823 [inline] zap_pud_range mm/memory.c:1852 [inline] zap_p4d_range mm/memory.c:1873 [inline] unmap_page_range+0x33cf/0x44d0 mm/memory.c:1894 unmap_vmas+0x3ce/0x5f0 mm/memory.c:1984 exit_mmap+0x2bc/0xde0 mm/mmap.c:1284 __mmput+0x115/0x420 kernel/fork.c:1379 exit_mm+0x221/0x310 kernel/exit.c:589 do_exit+0x994/0x27f0 kernel/exit.c:940 do_group_exit+0x207/0x2c0 kernel/exit.c:1102 get_signal+0x1696/0x1730 kernel/signal.c:3034 arch_do_signal_or_restart+0x98/0x810 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f6f0bd8e169 Code: Unable to access opcode bytes at 0x7f6f0bd8e13f. RSP: 002b:00007f6f0cb300e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: fffffffffffffe00 RBX: 00007f6f0bfb5fa8 RCX: 00007f6f0bd8e169 RDX: 0000000000000000 RSI: 0000000000000080 RDI: 00007f6f0bfb5fa8 RBP: 00007f6f0bfb5fa0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00007f6f0bfb5fac R13: 0000000000000000 R14: 00007f6f0c0df940 R15: 00007f6f0c0dfa28 rcu: rcu_preempt kthread starved for 10505 jiffies! g169761 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:26976 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5382 [inline] __schedule+0x1b88/0x5240 kernel/sched/core.c:6767 __schedule_loop kernel/sched/core.c:6845 [inline] schedule+0x163/0x360 kernel/sched/core.c:6860 schedule_timeout+0x15b/0x2b0 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x2e1/0x1340 kernel/rcu/tree.c:2046 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2248 kthread+0x7b7/0x940 kernel/kthread.c:464 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:153 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: 22770 Comm: syz.2.4441 Not tainted 6.15.0-rc2-syzkaller-00471-g119009db2674 #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 02/12/2025 RIP: 0010:csd_lock_wait kernel/smp.c:340 [inline] RIP: 0010:smp_call_function_many_cond+0x1bac/0x2d40 kernel/smp.c:885 Code: 03 84 c0 75 7e 45 8b 65 00 44 89 e6 83 e6 01 31 ff e8 88 dd 0b 00 41 83 e4 01 4c 8b 64 24 68 75 07 e8 38 d9 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 RSP: 0018:ffffc9000ce2f380 EFLAGS: 00000293 RAX: ffffffff81b6e40d RBX: 1ffff110170e7e91 RCX: ffff888054888000 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc9000ce2f580 R08: ffffffff81b6e3d8 R09: 1ffffffff20bfc8e R10: dffffc0000000000 R11: fffffbfff20bfc8f R12: ffff8880b863ad08 R13: ffff8880b873f488 R14: ffff8880b863ad00 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888124f9a000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000200000404030 CR3: 000000000eb38000 CR4: 00000000003526f0 DR0: 000000000000000e DR1: 000000000000000c DR2: 000000000000000e DR3: 00000000000000b4 DR6: 00000000ffff0ff0 DR7: 0000000000000400 Call Trace: 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:1275 [inline] flush_tlb_mm_range+0xb8d/0x13f0 arch/x86/mm/tlb.c:1365 tlb_flush arch/x86/include/asm/tlb.h:23 [inline] tlb_flush_mmu_tlbonly include/asm-generic/tlb.h:480 [inline] tlb_flush_mmu+0x1aa/0x690 mm/mmu_gather.c:403 tlb_finish_mmu+0xd4/0x200 mm/mmu_gather.c:496 exit_mmap+0x5b1/0xde0 mm/mmap.c:1297 __mmput+0x115/0x420 kernel/fork.c:1379 exit_mm+0x221/0x310 kernel/exit.c:589 do_exit+0x994/0x27f0 kernel/exit.c:940 do_group_exit+0x207/0x2c0 kernel/exit.c:1102 get_signal+0x1696/0x1730 kernel/signal.c:3034 arch_do_signal_or_restart+0x98/0x810 arch/x86/kernel/signal.c:337 exit_to_user_mode_loop kernel/entry/common.c:111 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:329 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0xce/0x340 kernel/entry/common.c:218 do_syscall_64+0x100/0x210 arch/x86/entry/syscall_64.c:100 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7ffb4918e169 Code: Unable to access opcode bytes at 0x7ffb4918e13f. RSP: 002b:00007ffb46ff6038 EFLAGS: 00000246 ORIG_RAX: 000000000000012b RAX: 0000000000010106 RBX: 00007ffb493b6080 RCX: 00007ffb4918e169 RDX: 0000000000010106 RSI: 00002000000000c0 RDI: 0000000000000004 RBP: 00007ffb49210a68 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000002 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000001 R14: 00007ffb493b6080 R15: 00007ffb494dfa28