sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 0-...!: (1 ticks this GP) idle=82b4/1/0x4000000000000000 softirq=22774/22774 fqs=0 rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P7464/1:b..l P7460/1:b..l rcu: (detected by 1, t=10502 jiffies, g=18353, q=330 ncpus=2) Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 3 Comm: pool_workqueue_ Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/02/2025 RIP: 0010:do_raw_spin_lock+0x1c/0x290 kernel/locking/spinlock_debug.c:114 Code: 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 55 48 89 e5 41 57 41 56 41 55 41 54 53 48 83 e4 e0 48 81 ec 80 00 00 00 <48> 89 fb 65 48 8b 05 e9 49 f3 10 48 89 44 24 60 49 bf 00 00 00 00 RSP: 0018:ffffc90000007ba0 EFLAGS: 00000086 RAX: 8c5de88993075e00 RBX: ffff888032c68036 RCX: 8c5de88993075e00 RDX: 0000000000000000 RSI: ffffffff8d9d398d RDI: ffff888027ffb2e8 RBP: ffffc90000007c60 R08: 0000000000000000 R09: ffffffff89672734 R10: dffffc0000000000 R11: ffffffff89672670 R12: ffff888027ffb340 R13: ffff888027ffb000 R14: dffffc0000000000 R15: ffff8881404c4798 FS: 0000000000000000(0000) GS:ffff888125d08000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 0000001b30e23ffc CR3: 000000006659c000 CR4: 00000000003526f0 Call Trace: spin_lock include/linux/spinlock.h:351 [inline] advance_sched+0xc4/0xc90 net/sched/sch_taprio.c:929 __run_hrtimer kernel/time/hrtimer.c:1777 [inline] __hrtimer_run_queues+0x52c/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:lockdep_unregister_key+0x2c5/0x310 kernel/locking/lockdep.c:6616 Code: 65 48 8b 05 cd c8 f3 10 48 3b 44 24 10 0f 84 26 fe ff ff e8 7d e9 ae 09 e8 a8 ea ae 09 41 f7 c7 00 02 00 00 74 bd fb 40 84 ed <75> bc eb cd 90 0f 0b 90 e9 19 ff ff ff 90 0f 0b 90 e9 2a ff ff ff RSP: 0018:ffffc90000087be0 EFLAGS: 00000246 RAX: 8c5de88993075e00 RBX: ffff888032efb138 RCX: 8c5de88993075e00 RDX: ffffffff93553358 RSI: ffffffff8d7feb15 RDI: ffffffff8bc07de0 RBP: ffff888032efb100 R08: 0000000000000000 R09: ffffffff81aab398 R10: dffffc0000000000 R11: fffffbfff1f3c66f R12: 0000000000000000 R13: 0000000000001000 R14: 0000000000000001 R15: 0000000000000202 wq_unregister_lockdep kernel/workqueue.c:4848 [inline] pwq_release_workfn+0x6d5/0x870 kernel/workqueue.c:5144 kthread_worker_fn+0x507/0xb60 kernel/kthread.c:1010 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 task:udevadm state:R running task stack:24584 pid:7460 tgid:7460 ppid:7103 task_flags:0x400000 flags:0x00080001 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7256 irqentry_exit+0x6f/0x90 kernel/entry/common.c:211 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:697 RIP: 0010:lock_release+0x2b5/0x3e0 kernel/locking/lockdep.c:5893 Code: 51 48 c7 44 24 20 00 00 00 00 9c 8f 44 24 20 f7 44 24 20 00 02 00 00 75 56 f7 c3 00 02 00 00 74 01 fb 65 48 8b 05 8b da f3 10 <48> 3b 44 24 28 0f 85 8b 00 00 00 48 83 c4 30 5b 41 5c 41 5d 41 5e RSP: 0018:ffffc9001a8a7810 EFLAGS: 00000206 RAX: c3d3f123f3f8c500 RBX: 0000000000000206 RCX: c3d3f123f3f8c500 RDX: 0000000000000000 RSI: ffffffff8d9d398d RDI: ffffffff8bc07de0 RBP: ffff88802bb92970 R08: ffffc9001a8a7d90 R09: 0000000000000000 R10: ffffc9001a8a7998 R11: fffff52003514f35 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8e13d2e0 R15: ffff88802bb91e40 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:56 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:77 unpoison_slab_object mm/kasan/common.c:342 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:368 kasan_slab_alloc include/linux/kasan.h:252 [inline] slab_post_alloc_hook mm/slub.c:4955 [inline] slab_alloc_node mm/slub.c:5265 [inline] kmem_cache_alloc_noprof+0x367/0x6e0 mm/slub.c:5272 getname_flags+0xb8/0x540 fs/namei.c:146 getname include/linux/fs.h:2922 [inline] do_sys_openat2+0xbc/0x1c0 fs/open.c:1431 do_sys_open fs/open.c:1452 [inline] __do_sys_openat fs/open.c:1468 [inline] __se_sys_openat fs/open.c:1463 [inline] __x64_sys_openat+0x138/0x170 fs/open.c:1463 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: 0033:0x7f72768a7407 RSP: 002b:00007ffe5f36f4b0 EFLAGS: 00000202 ORIG_RAX: 0000000000000101 RAX: ffffffffffffffda RBX: 00007f7276fd4880 RCX: 00007f72768a7407 RDX: 0000000000080000 RSI: 00007ffe5f36f630 RDI: ffffffffffffff9c RBP: 0000000000000008 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000202 R12: 00005573dfa76ee0 R13: 00005573dfa76ee0 R14: 0000000000000001 R15: 00005573e697ae60 task:syz.2.270 state:R running task stack:26376 pid:7464 tgid:7464 ppid:5827 task_flags:0x40004c flags:0x00080000 Call Trace: context_switch kernel/sched/core.c:5325 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6929 preempt_schedule_notrace+0xd1/0x110 kernel/sched/core.c:7206 preempt_schedule_notrace_thunk+0x16/0x30 arch/x86/entry/thunk.S:13 rcu_is_watching+0x7f/0xb0 kernel/rcu/tree.c:752 trace_lock_release include/trace/events/lock.h:69 [inline] lock_release+0x4b/0x3e0 kernel/locking/lockdep.c:5879 rcu_lock_release include/linux/rcupdate.h:341 [inline] rcu_read_unlock include/linux/rcupdate.h:897 [inline] class_rcu_destructor include/linux/rcupdate.h:1195 [inline] unwind_next_frame+0x19a9/0x2390 arch/x86/kernel/unwind_orc.c:680 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 kasan_save_stack+0x3e/0x60 mm/kasan/common.c:56 kasan_record_aux_stack+0xbd/0xd0 mm/kasan/generic.c:559 __call_rcu_common kernel/rcu/tree.c:3123 [inline] call_rcu+0x157/0x9c0 kernel/rcu/tree.c:3243 slab_free_hook mm/slub.c:2487 [inline] slab_free mm/slub.c:6611 [inline] kmem_cache_free+0x4b5/0x690 mm/slub.c:6721 exit_mmap+0x537/0xb40 mm/mmap.c:1305 __mmput+0x118/0x430 kernel/fork.c:1133 exit_mm+0x1da/0x2c0 kernel/exit.c:582 do_exit+0x648/0x2300 kernel/exit.c:954 do_group_exit+0x21c/0x2d0 kernel/exit.c:1107 __do_sys_exit_group kernel/exit.c:1118 [inline] __se_sys_exit_group kernel/exit.c:1116 [inline] __x64_sys_exit_group+0x3f/0x40 kernel/exit.c:1116 x64_sys_call+0x21f7/0x2200 arch/x86/include/generated/asm/syscalls_64.h:232 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: 0033:0x7f3a9518eec9 RSP: 002b:00007ffe109a3e78 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f3a9518eec9 RDX: 0000000000000064 RSI: 0000000000000000 RDI: 0000000000000000 RBP: 00007ffe109a3edc R08: 00000002109a3f6f R09: 00000000000927c0 R10: 0000000000002874 R11: 0000000000000246 R12: 0000000000000039 R13: 00000000000927c0 R14: 0000000000043cd8 R15: 00007ffe109a3f30 rcu: rcu_preempt kthread timer wakeup didn't happen for 10501 jiffies! g18353 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x402 rcu: Possible timer handling issue on cpu=0 timer-softirq=19145 rcu: rcu_preempt kthread starved for 10502 jiffies! g18353 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:27200 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