sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 GPs behind) idle=583c/1/0x4000000000000000 softirq=91585/91587 fqs=0 rcu: (detected by 1, t=10502 jiffies, g=69853, q=55 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 5193 Comm: udevd Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:cpu_max_bits_warn include/linux/cpumask.h:135 [inline] RIP: 0010:cpumask_check include/linux/cpumask.h:142 [inline] RIP: 0010:cpumask_test_cpu include/linux/cpumask.h:646 [inline] RIP: 0010:cpu_online include/linux/cpumask.h:1205 [inline] RIP: 0010:trace_hrtimer_expire_entry include/trace/events/timer.h:259 [inline] RIP: 0010:__run_hrtimer kernel/time/hrtimer.c:1774 [inline] RIP: 0010:__hrtimer_run_queues+0x41a/0xc60 kernel/time/hrtimer.c:1841 Code: 1e 78 00 4d 8b 36 48 8b 7c 24 40 48 8b b4 24 a8 00 00 00 e8 88 6f 9b 09 0f 1f 44 00 00 e8 9e 5c 12 00 65 44 8b 2d 0a a9 c0 10 07 00 00 00 44 89 ee e8 c9 60 12 00 41 83 fd 07 0f 87 cb 02 00 RSP: 0018:ffffc90000007d40 EFLAGS: 00000006 RAX: ffffffff81ada722 RBX: ffff8880b8827d08 RCX: ffff88807ce6dac0 RDX: 0000000000010000 RSI: 0000000000000004 RDI: 00000000ffffffff RBP: ffffc90000007e90 R08: ffff8880b8827ac3 R09: 1ffff11017104f58 R10: dffffc0000000000 R11: ffffed1017104f59 R12: ffff88802f859340 R13: 0000000000000000 R14: ffffffff89601c80 R15: 00000000fffffff7 FS: 00007f19b609d880(0000) GS:ffff88812613b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b34d23ffc CR3: 000000001fbfa000 CR4: 0000000000350ef0 Call Trace: 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:lock_acquire+0x175/0x360 kernel/locking/lockdep.c:5872 Code: 00 00 00 00 9c 8f 44 24 30 f7 44 24 30 00 02 00 00 0f 85 cd 00 00 00 f7 44 24 08 00 02 00 00 74 01 fb 65 48 8b 05 5b fd d0 10 <48> 3b 44 24 58 0f 85 f2 00 00 00 48 83 c4 60 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc90003b6faa0 EFLAGS: 00000206 RAX: 995d87538eedbd00 RBX: 0000000000000000 RCX: 995d87538eedbd00 RDX: 0000000000000000 RSI: ffffffff8d8f50e4 RDI: ffffffff8bbf08e0 RBP: ffffffff82467da6 R08: 0000000000000000 R09: ffffffff82467da6 R10: dffffc0000000000 R11: fffff5200076df92 R12: 0000000000000000 R13: ffff88804d5b1ca8 R14: 0000000000000001 R15: 0000000000000246 down_write+0x96/0x1f0 kernel/locking/rwsem.c:1590 inode_lock include/linux/fs.h:980 [inline] vfs_utimes+0x396/0x570 fs/utimes.c:65 do_utimes_fd fs/utimes.c:117 [inline] do_utimes+0x182/0x2a0 fs/utimes.c:139 __do_sys_utimensat fs/utimes.c:159 [inline] __se_sys_utimensat fs/utimes.c:143 [inline] __x64_sys_utimensat+0x14f/0x230 fs/utimes.c:143 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: 0033:0x7f19b59159ea Code: 10 48 89 fe 31 c9 bf 9c ff ff ff e8 10 00 00 00 48 83 c4 28 c3 66 2e 0f 1f 84 00 00 00 00 00 90 41 89 ca b8 18 01 00 00 0f 05 <48> 3d 00 f0 ff ff 77 06 c3 0f 1f 44 00 00 48 8b 15 d9 b3 0d 00 f7 RSP: 002b:00007ffc50e4d868 EFLAGS: 00000246 ORIG_RAX: 0000000000000118 RAX: ffffffffffffffda RBX: 000000000000000c RCX: 00007f19b59159ea RDX: 0000000000000000 RSI: 0000000000000000 RDI: 000000000000000c RBP: 0000000000000000 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 00000000ffffffff R13: 00000000ffffffff R14: ffffffffffffffff R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10502 jiffies! g69853 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:27088 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: 1 UID: 0 PID: 14506 Comm: syz.5.1573 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/25/2025 RIP: 0010:get_current arch/x86/include/asm/current.h:25 [inline] RIP: 0010:__sanitizer_cov_trace_pc+0x8/0x70 kernel/kcov.c:216 Code: 8b 3d 54 e2 d2 0b 48 89 de 5b e9 83 8b 5a 00 cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 48 8b 04 24 <65> 48 8b 0c 25 08 50 6e 92 65 8b 15 58 4c ae 10 81 e2 00 01 ff 00 RSP: 0018:ffffc9000c177938 EFLAGS: 00000202 RAX: ffffffff81b4944b RBX: 1ffff11017108441 RCX: 0000000000080000 RDX: ffffc900141a7000 RSI: 000000000007ffff RDI: 0000000000080000 RBP: ffffc9000c177ab0 R08: ffffffff8f7cee77 R09: 1ffffffff1ef9dce R10: dffffc0000000000 R11: ffffffff8170f180 R12: ffff8880b8842208 R13: dffffc0000000000 R14: ffff8880b893b240 R15: 0000000000000000 FS: 00007f0caba746c0(0000) GS:ffff88812623b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000110c2c6d31 CR3: 000000005d499000 CR4: 0000000000350ef0 Call Trace: csd_lock_wait kernel/smp.c:342 [inline] smp_call_function_many_cond+0xd4b/0x12d0 kernel/smp.c:877 clock_was_set+0x709/0x7c0 kernel/time/hrtimer.c:969 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: 0033:0x7f0caab8f749 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:00007f0caba74038 EFLAGS: 00000246 ORIG_RAX: 0000000000000131 RAX: ffffffffffffffda RBX: 00007f0caade5fa0 RCX: 00007f0caab8f749 RDX: 0000000000000000 RSI: 00002000000001c0 RDI: 0000000000000000 RBP: 00007f0caac13f91 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 00007f0caade6038 R14: 00007f0caade5fa0 R15: 00007ffd16a17ff8