sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: 1-...!: (1 GPs behind) idle=46e4/1/0x4000000000000000 softirq=19116/19127 fqs=2 rcu: (detected by 0, t=10502 jiffies, g=13533, q=812 ncpus=2) Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 6155 Comm: rm Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 RIP: 0010:debug_object_activate+0x0/0x420 lib/debugobjects.c:805 Code: 5d 1c d3 0a 00 74 06 e9 0e 8f ac 06 cc ba 01 00 00 00 e9 13 fc ff ff 0f 1f 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 0f 1e fa 55 41 57 41 56 41 55 41 54 53 48 83 ec 48 49 89 f6 48 RSP: 0018:ffffc90000a08d00 EFLAGS: 00000006 RAX: ffffffff81adf4d1 RBX: ffff888057344340 RCX: ffff88807d180000 RDX: 0000000000010000 RSI: ffffffff8b8cf580 RDI: ffff888057344340 RBP: 0000000000000000 R08: 0000000000000003 R09: 0000000000000004 R10: dffffc0000000000 R11: fffff52000141184 R12: dffffc0000000000 R13: dffffc0000000000 R14: ffff8880b8727b80 R15: ffff8880b8727b80 FS: 0000000000000000(0000) GS:ffff888125d16000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00007f3bd64014e8 CR3: 0000000076d70000 CR4: 00000000003526f0 Call Trace: debug_hrtimer_activate kernel/time/hrtimer.c:445 [inline] debug_activate kernel/time/hrtimer.c:484 [inline] enqueue_hrtimer+0x30/0x3a0 kernel/time/hrtimer.c:1088 __run_hrtimer kernel/time/hrtimer.c:1778 [inline] __hrtimer_run_queues+0x656/0xc60 kernel/time/hrtimer.c:1825 hrtimer_interrupt+0x45b/0xaa0 kernel/time/hrtimer.c:1887 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1039 [inline] __sysvec_apic_timer_interrupt+0x108/0x410 arch/x86/kernel/apic/apic.c:1056 instr_sysvec_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1050 [inline] sysvec_apic_timer_interrupt+0xa1/0xc0 arch/x86/kernel/apic/apic.c:1050 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:unwind_next_frame+0x67/0x2390 arch/x86/kernel/unwind_orc.c:470 Code: 62 b0 00 48 89 5c 24 18 49 8b 5e 48 4d 8d 6e 38 4c 89 e8 48 c1 e8 03 48 89 44 24 58 80 3c 28 00 74 08 4c 89 ef e8 c9 62 b0 00 <4d> 8b 7e 38 4d 89 f4 49 c1 ec 03 41 0f b6 04 2c 84 c0 0f 85 de 1b RSP: 0018:ffffc90003066db8 EFLAGS: 00000246 RAX: 1ffff9200060cdd8 RBX: ffffffff81ac4aac RCX: 8fbbc9a370ce6000 RDX: dffffc0000000000 RSI: ffffffff81ac4aac RDI: ffffc90003066e88 RBP: dffffc0000000000 R08: ffffc90003066f50 R09: 0000000000000000 R10: ffffc90003066ed8 R11: ffffffff81ac4b00 R12: ffff88807d180000 R13: ffffc90003066ec0 R14: ffffc90003066e88 R15: ffffc90003066e88 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:47 [inline] kasan_save_track+0x3e/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:330 [inline] __kasan_slab_alloc+0x6c/0x80 mm/kasan/common.c:356 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4191 [inline] slab_alloc_node mm/slub.c:4240 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4247 mt_alloc_one lib/maple_tree.c:176 [inline] mas_alloc_nodes+0x2e9/0x8e0 lib/maple_tree.c:1255 mas_node_count_gfp lib/maple_tree.c:1337 [inline] mas_preallocate+0x3ad/0x6f0 lib/maple_tree.c:5537 vma_iter_prealloc mm/vma.h:462 [inline] __split_vma+0x2fa/0xa00 mm/vma.c:528 vms_gather_munmap_vmas+0x4ce/0x12f0 mm/vma.c:1380 __mmap_prepare mm/vma.c:2359 [inline] __mmap_region mm/vma.c:2651 [inline] mmap_region+0x724/0x20c0 mm/vma.c:2739 do_mmap+0xc45/0x10d0 mm/mmap.c:558 vm_mmap_pgoff+0x2a6/0x4d0 mm/util.c:580 ksys_mmap_pgoff+0x51f/0x760 mm/mmap.c:604 do_syscall_x64 arch/x86/entry/syscall_64.c:63 [inline] do_syscall_64+0xfa/0x3b0 arch/x86/entry/syscall_64.c:94 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f3bd6432242 Code: 08 00 04 00 00 eb e2 90 41 f7 c1 ff 0f 00 00 75 27 55 89 cd 53 48 89 fb 48 85 ff 74 33 41 89 ea 48 89 df b8 09 00 00 00 0f 05 <48> 3d 00 f0 ff ff 77 5e 5b 5d c3 0f 1f 00 c7 05 46 40 01 00 16 00 RSP: 002b:00007fffdd9d1388 EFLAGS: 00000206 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f3bd6331000 RCX: 00007f3bd6432242 RDX: 0000000000000003 RSI: 0000000000006000 RDI: 00007f3bd6331000 RBP: 0000000000000812 R08: 0000000000000003 R09: 00000000001cc000 R10: 0000000000000812 R11: 0000000000000206 R12: 00007fffdd9d1448 R13: 00007f3bd64065f0 R14: 00007fffdd9d1bc0 R15: 00000ffffbb3a274 rcu: rcu_preempt kthread starved for 10498 jiffies! g13533 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:26792 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5357 [inline] __schedule+0x1798/0x4cc0 kernel/sched/core.c:6961 __schedule_loop kernel/sched/core.c:7043 [inline] schedule+0x165/0x360 kernel/sched/core.c:7058 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+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 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: 36 Comm: kworker/u8:2 Not tainted syzkaller #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 08/18/2025 Workqueue: events_unbound toggle_allocation_gate RIP: 0010:csd_lock_wait kernel/smp.c:342 [inline] RIP: 0010:smp_call_function_many_cond+0xd38/0x12d0 kernel/smp.c:877 Code: 89 ee 83 e6 01 31 ff e8 56 63 0b 00 41 83 e5 01 49 bd 00 00 00 00 00 fc ff df 75 07 e8 01 5f 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 e5 5e 0b 00 eb e4 44 RSP: 0018:ffffc90000ac7660 EFLAGS: 00000293 RAX: 0000000000000000 RBX: 1ffff110170e7f69 RCX: ffff88801d6f5a00 RDX: 0000000000000000 RSI: 0000000000000001 RDI: 0000000000000000 RBP: ffffc90000ac77e0 R08: ffffffff8fa38837 R09: 1ffffffff1f47106 R10: dffffc0000000000 R11: fffffbfff1f47107 R12: ffff8880b873fb48 R13: dffffc0000000000 R14: ffff8880b863b1c0 R15: 0000000000000001 FS: 0000000000000000(0000) GS:ffff888125c16000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000055be87dbbae8 CR3: 000000000df36000 CR4: 00000000003526f0 Call Trace: on_each_cpu_cond_mask+0x3f/0x80 kernel/smp.c:1044 on_each_cpu include/linux/smp.h:71 [inline] smp_text_poke_sync_each_cpu arch/x86/kernel/alternative.c:2653 [inline] smp_text_poke_batch_finish+0x5f9/0x1130 arch/x86/kernel/alternative.c:2863 arch_jump_label_transform_apply+0x1c/0x30 arch/x86/kernel/jump_label.c:146 static_key_enable_cpuslocked+0x128/0x250 kernel/jump_label.c:210 static_key_enable+0x1a/0x20 kernel/jump_label.c:223 toggle_allocation_gate+0xad/0x240 mm/kfence/core.c:850 process_one_work kernel/workqueue.c:3236 [inline] process_scheduled_works+0xae1/0x17b0 kernel/workqueue.c:3319 worker_thread+0x8a0/0xda0 kernel/workqueue.c:3400 kthread+0x70e/0x8a0 kernel/kthread.c:463 ret_from_fork+0x436/0x7d0 arch/x86/kernel/process.c:148 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245