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): P7864/1:b..l rcu: (detected by 0, t=10503 jiffies, g=37169, q=651096 ncpus=2) task:syz-executor state:R running task stack:23072 pid:7864 tgid:7864 ppid:5218 flags:0x00000000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7004 irqentry_exit+0x5e/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:kasan_check_range+0x5/0x290 mm/kasan/generic.c:188 Code: 8e e8 cf df e1 ff 90 0f 0b 66 2e 0f 1f 84 00 00 00 00 00 66 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 66 0f 1f 00 55 <41> 57 41 56 41 54 53 b0 01 48 85 f6 0f 84 a0 01 00 00 4c 8d 04 37 RSP: 0018:ffffc90003a3f650 EFLAGS: 00000246 RAX: 0000000000000000 RBX: 0000000000000000 RCX: ffffffff817056d4 RDX: 0000000000000000 RSI: 0000000000000008 RDI: ffffffff901cfde8 RBP: ffffc90003a3f7b0 R08: 0000000000000000 R09: 0000000000000000 R10: dffffc0000000000 R11: ffffed1004961478 R12: 1ffff92000747ed4 R13: dffffc0000000000 R14: 0000000000000000 R15: 0000000000000000 instrument_atomic_read include/linux/instrumented.h:68 [inline] _test_bit include/asm-generic/bitops/instrumented-non-atomic.h:141 [inline] cpumask_test_cpu include/linux/cpumask.h:570 [inline] cpu_online include/linux/cpumask.h:1117 [inline] trace_lock_acquire include/trace/events/lock.h:24 [inline] lock_acquire+0xd4/0x550 kernel/locking/lockdep.c:5796 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock include/linux/rcupdate.h:849 [inline] page_ext_get+0x3d/0x2a0 mm/page_ext.c:525 __page_table_check_zero+0xb1/0x350 mm/page_table_check.c:148 page_table_check_alloc include/linux/page_table_check.h:33 [inline] post_alloc_hook+0x206/0x230 mm/page_alloc.c:1538 prep_new_page mm/page_alloc.c:1545 [inline] get_page_from_freelist+0x3045/0x3190 mm/page_alloc.c:3457 __alloc_pages_noprof+0x292/0x710 mm/page_alloc.c:4733 alloc_pages_mpol_noprof+0x3e8/0x680 mm/mempolicy.c:2265 vm_area_alloc_pages mm/vmalloc.c:3568 [inline] __vmalloc_area_node mm/vmalloc.c:3646 [inline] __vmalloc_node_range_noprof+0xa2b/0x13f0 mm/vmalloc.c:3828 vmalloc_user_noprof+0x74/0x80 mm/vmalloc.c:3982 kcov_ioctl+0x56/0x640 kernel/kcov.c:716 vfs_ioctl fs/ioctl.c:51 [inline] __do_sys_ioctl fs/ioctl.c:907 [inline] __se_sys_ioctl+0xf9/0x170 fs/ioctl.c:893 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xf3/0x230 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f536577dbfb RSP: 002b:00007ffd5efbcd90 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 0000000000100000 RCX: 00007f536577dbfb RDX: 0000000000100000 RSI: ffffffff80086301 RDI: 00000000000000d7 RBP: 00007f5365935f40 R08: 00000000000000da R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000001 R13: 0000000000000003 R14: 0000000000000009 R15: 0000000000000000 rcu: rcu_preempt kthread starved for 10320 jiffies! g37169 f0x2 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:25200 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5322 [inline] __schedule+0x1895/0x4b30 kernel/sched/core.c:6682 __schedule_loop kernel/sched/core.c:6759 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6774 schedule_timeout+0x1be/0x310 kernel/time/timer.c:2615 rcu_gp_fqs_loop+0x2df/0x1330 kernel/rcu/tree.c:2045 rcu_gp_kthread+0xa7/0x3b0 kernel/rcu/tree.c:2247 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 CPU: 1 UID: 0 PID: 2636 Comm: kworker/1:2 Not tainted 6.12.0-rc3-syzkaller-00044-g2f87d0916ce0 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 09/13/2024 Workqueue: events nsim_dev_trap_report_work RIP: 0010:validate_chain+0xdc/0x5920 kernel/locking/lockdep.c:3871 Code: 89 44 21 2b 48 89 8c 24 c0 00 00 00 42 c6 44 21 33 f3 48 89 b4 24 b0 00 00 00 4c 8d 6e 20 4c 89 e8 48 c1 e8 03 48 89 44 24 60 <42> 0f b6 04 20 84 c0 0f 85 ef 4c 00 00 41 8b 5d 00 89 d8 25 00 80 RSP: 0018:ffffc90000a176a0 EFLAGS: 00000806 RAX: 1ffff11005adecc3 RBX: ffffffff93c6ccc0 RCX: 1ffff92000142ef4 RDX: 0000000000000000 RSI: ffff88802d6f65f8 RDI: ffff88802d6f5a00 RBP: ffffc90000a179a0 R08: ffffffff942c986f R09: 1ffffffff285930d R10: dffffc0000000000 R11: fffffbfff285930e R12: dffffc0000000000 R13: ffff88802d6f6618 R14: cc4eb368cb759dbf R15: ffff88802d6f6618 FS: 0000000000000000(0000) GS:ffff8880b8700000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 000000002010a030 CR3: 000000007cca4000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: __lock_acquire+0x1384/0x2050 kernel/locking/lockdep.c:5202 lock_acquire+0x1ed/0x550 kernel/locking/lockdep.c:5825 rcu_lock_acquire include/linux/rcupdate.h:337 [inline] rcu_read_lock_bh include/linux/rcupdate.h:903 [inline] __dev_queue_xmit+0x30b/0x3ed0 net/core/dev.c:4353 dev_queue_xmit include/linux/netdevice.h:3094 [inline] neigh_hh_output include/net/neighbour.h:526 [inline] neigh_output include/net/neighbour.h:540 [inline] ip_finish_output2+0xd41/0x1390 net/ipv4/ip_output.c:236 synproxy_send_client_synack+0x8b8/0xf30 net/netfilter/nf_synproxy_core.c:484 nft_synproxy_eval_v4+0x3ca/0x610 net/netfilter/nft_synproxy.c:59 nft_synproxy_do_eval+0x362/0xa60 net/netfilter/nft_synproxy.c:141 expr_call_ops_eval net/netfilter/nf_tables_core.c:240 [inline] nft_do_chain+0x4ad/0x1da0 net/netfilter/nf_tables_core.c:288 nft_do_chain_inet+0x418/0x6b0 net/netfilter/nft_chain_filter.c:161 nf_hook_entry_hookfn include/linux/netfilter.h:154 [inline] nf_hook_slow+0xc3/0x220 net/netfilter/core.c:626 nf_hook include/linux/netfilter.h:269 [inline] NF_HOOK+0x29e/0x450 include/linux/netfilter.h:312 NF_HOOK+0x3a4/0x450 include/linux/netfilter.h:314 __netif_receive_skb_one_core net/core/dev.c:5666 [inline] __netif_receive_skb+0x2bf/0x650 net/core/dev.c:5779 process_backlog+0x662/0x15b0 net/core/dev.c:6111 __napi_poll+0xcb/0x490 net/core/dev.c:6775 napi_poll net/core/dev.c:6844 [inline] net_rx_action+0x89b/0x1240 net/core/dev.c:6966 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 do_softirq+0x11b/0x1e0 kernel/softirq.c:455 __local_bh_enable_ip+0x1bb/0x200 kernel/softirq.c:382 spin_unlock_bh include/linux/spinlock.h:396 [inline] nsim_dev_trap_report drivers/net/netdevsim/dev.c:820 [inline] nsim_dev_trap_report_work+0x75d/0xaa0 drivers/net/netdevsim/dev.c:850 process_one_work kernel/workqueue.c:3229 [inline] process_scheduled_works+0xa63/0x1850 kernel/workqueue.c:3310 worker_thread+0x870/0xd30 kernel/workqueue.c:3391 kthread+0x2f0/0x390 kernel/kthread.c:389 ret_from_fork+0x4b/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244