sched: DL replenish lagged too much rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5862/1:b..l rcu: (detected by 1, t=10503 jiffies, g=19885, q=850 ncpus=2) task:syz-executor state:R running task stack:21960 pid:5862 tgid:5862 ppid:5844 task_flags:0x400140 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6790 preempt_schedule_irq+0xb5/0x150 kernel/sched/core.c:7113 irqentry_exit+0x6f/0x90 kernel/entry/common.c:307 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:kasan_check_byte include/linux/kasan.h:399 [inline] RIP: 0010:lock_acquire+0x85/0x360 kernel/locking/lockdep.c:5845 Code: 41 f1 08 00 84 c0 75 0d f6 05 72 99 ed 0d 01 0f 84 d7 01 00 00 83 3d a9 e6 03 0e 00 0f 84 f0 00 00 00 48 8b b4 24 90 00 00 00 <4c> 89 ef e8 53 50 85 00 83 3d 8c e6 03 0e 00 0f 84 fa 00 00 00 65 RSP: 0018:ffffc900040bf118 EFLAGS: 00000202 RAX: 0000000000000001 RBX: 0000000000000000 RCX: 677a2dac141ace00 RDX: 0000000000000000 RSI: ffffffff8172ab02 RDI: ffffffff8be29d60 RBP: ffffffff8172aae5 R08: 0000000000000000 R09: 0000000000000000 R10: ffffc900040bf2d8 R11: ffffffff81ad03a0 R12: 0000000000000002 R13: ffffffff8e13f160 R14: 0000000000000000 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:331 [inline] rcu_read_lock include/linux/rcupdate.h:841 [inline] class_rcu_constructor include/linux/rcupdate.h:1155 [inline] unwind_next_frame+0xc2/0x2390 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x9c/0xe0 kernel/stacktrace.c:122 save_stack+0xf5/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x71/0x1f0 mm/page_owner.c:308 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1248 [inline] __free_frozen_pages+0xc71/0xe70 mm/page_alloc.c:2706 discard_slab mm/slub.c:2717 [inline] __put_partials+0x161/0x1c0 mm/slub.c:3186 put_cpu_partial+0x17c/0x250 mm/slub.c:3261 __slab_free+0x2f7/0x400 mm/slub.c:4513 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x97/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x148/0x160 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x22/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:250 [inline] slab_post_alloc_hook mm/slub.c:4148 [inline] slab_alloc_node mm/slub.c:4197 [inline] kmem_cache_alloc_noprof+0x1c1/0x3c0 mm/slub.c:4204 anon_vma_chain_alloc mm/rmap.c:142 [inline] anon_vma_fork+0x1f1/0x500 mm/rmap.c:364 dup_mmap+0x9eb/0x1ac0 mm/mmap.c:1801 dup_mm kernel/fork.c:1477 [inline] copy_mm+0x13c/0x4b0 kernel/fork.c:1529 copy_process+0x16d3/0x3b80 kernel/fork.c:2169 kernel_clone+0x21e/0x870 kernel/fork.c:2599 __do_sys_clone kernel/fork.c:2742 [inline] __se_sys_clone kernel/fork.c:2726 [inline] __x64_sys_clone+0x18b/0x1e0 kernel/fork.c:2726 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: 0033:0x7f8f77f85193 RSP: 002b:00007f8f782dfca8 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f8f77f85193 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 0000000000000001 R08: 0000000000000000 R09: 0000000000000001 R10: 00005555781cc7d0 R11: 0000000000000246 R12: 0000000000000000 R13: 00000000000927c0 R14: 0000000000028659 R15: 00007f8f782dfe40 rcu: rcu_preempt kthread starved for 1230 jiffies! g19885 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:27192 pid:16 tgid:16 ppid:2 task_flags:0x208040 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5401 [inline] __schedule+0x16f5/0x4d00 kernel/sched/core.c:6790 __schedule_loop kernel/sched/core.c:6868 [inline] schedule+0x165/0x360 kernel/sched/core.c:6883 schedule_timeout+0x12b/0x270 kernel/time/sleep_timeout.c:99 rcu_gp_fqs_loop+0x301/0x1540 kernel/rcu/tree.c:2054 rcu_gp_kthread+0x99/0x390 kernel/rcu/tree.c:2256 kthread+0x70e/0x8a0 kernel/kthread.c:464 ret_from_fork+0x3fc/0x770 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: Sending NMI from CPU 1 to CPUs 0: NMI backtrace for cpu 0 CPU: 0 UID: 0 PID: 0 Comm: swapper/0 Not tainted 6.16.0-rc5-syzkaller-00193-g40f92e79b0aa #0 PREEMPT(full) Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 05/07/2025 RIP: 0010:pv_native_safe_halt+0x13/0x20 arch/x86/kernel/paravirt.c:82 Code: cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 66 90 0f 00 2d 93 0d 19 00 f3 0f 1e fa fb f4 c8 dd 02 00 cc cc cc cc cc cc cc cc 90 90 90 90 90 90 90 90 90 RSP: 0018:ffffffff8de07d80 EFLAGS: 000002c6 RAX: b5553f294ca38500 RBX: ffffffff81976c78 RCX: b5553f294ca38500 RDX: 0000000000000001 RSI: ffffffff8d998a4b RDI: ffffffff8be29dc0 RBP: ffffffff8de07ea8 R08: ffff8880b8632f5b R09: 1ffff110170c65eb R10: dffffc0000000000 R11: ffffed10170c65ec R12: ffffffff8fa1f3f0 R13: 0000000000000000 R14: 0000000000000000 R15: 1ffffffff1bd2a50 FS: 0000000000000000(0000) GS:ffff888125c1b000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00002000001fe030 CR3: 000000003142a000 CR4: 00000000003526f0 Call Trace: arch_safe_halt arch/x86/include/asm/paravirt.h:107 [inline] default_idle+0x13/0x20 arch/x86/kernel/process.c:749 default_idle_call+0x74/0xb0 kernel/sched/idle.c:117 cpuidle_idle_call kernel/sched/idle.c:185 [inline] do_idle+0x1e8/0x510 kernel/sched/idle.c:325 cpu_startup_entry+0x44/0x60 kernel/sched/idle.c:423 rest_init+0x2de/0x300 init/main.c:745 start_kernel+0x47d/0x500 init/main.c:1102 x86_64_start_reservations+0x24/0x30 arch/x86/kernel/head64.c:307 x86_64_start_kernel+0x143/0x1c0 arch/x86/kernel/head64.c:288 common_startup_64+0x13e/0x147