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): P12949/1:b..l P12966/1:b..l rcu: (detected by 0, t=10503 jiffies, g=48393, q=494 ncpus=2) task:dhcpcd-run-hook state:R running task stack:23072 pid:12966 tgid:12966 ppid:5510 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x184f/0x4c30 kernel/sched/core.c:6690 preempt_schedule_common+0x84/0xd0 kernel/sched/core.c:6869 preempt_schedule+0xe1/0xf0 kernel/sched/core.c:6893 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk.S:12 unwind_next_frame+0x18f8/0x22d0 arch/x86/kernel/unwind_orc.c:672 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 save_stack+0xfb/0x1f0 mm/page_owner.c:156 __reset_page_owner+0x76/0x430 mm/page_owner.c:297 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 discard_slab mm/slub.c:2677 [inline] __put_partials+0xeb/0x130 mm/slub.c:3145 put_cpu_partial+0x17c/0x250 mm/slub.c:3220 __slab_free+0x2ea/0x3d0 mm/slub.c:4449 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_slab_alloc+0x23/0x80 mm/kasan/common.c:329 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_noprof+0x135/0x2a0 mm/slub.c:4141 vm_area_dup+0x27/0x290 kernel/fork.c:488 dup_mmap kernel/fork.c:692 [inline] dup_mm kernel/fork.c:1675 [inline] copy_mm+0xb61/0x1e80 kernel/fork.c:1724 copy_process+0x1845/0x3d50 kernel/fork.c:2374 kernel_clone+0x226/0x8f0 kernel/fork.c:2786 __do_sys_clone kernel/fork.c:2929 [inline] __se_sys_clone kernel/fork.c:2913 [inline] __x64_sys_clone+0x258/0x2a0 kernel/fork.c:2913 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: 0033:0x7fce6b7d2a12 RSP: 002b:00007fff22482718 EFLAGS: 00000246 ORIG_RAX: 0000000000000038 RAX: ffffffffffffffda RBX: 0000000000000001 RCX: 00007fce6b7d2a12 RDX: 0000000000000000 RSI: 0000000000000000 RDI: 0000000001200011 RBP: 000055e4bde14b70 R08: 0000000000000000 R09: 0000000000000200 R10: 00007fce6b698650 R11: 0000000000000246 R12: 0000000000000084 R13: 0000000000000000 R14: 0000000000000000 R15: 0000000000000024 task:syz.0.1814 state:R running task stack:25336 pid:12949 tgid:12946 ppid:5839 flags:0x00004006 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x184f/0x4c30 kernel/sched/core.c:6690 preempt_schedule_irq+0xfb/0x1c0 kernel/sched/core.c:7012 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:__preempt_count_add kernel/rcu/tree.c:733 [inline] RIP: 0010:rcu_is_watching+0x8/0xb0 kernel/rcu/tree.c:736 Code: 7b 03 eb cd 66 2e 0f 1f 84 00 00 00 00 00 0f 1f 40 00 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 90 f3 0f 1e fa 41 57 41 56 <53> 65 ff 05 08 0e 89 7e e8 5b 0d 4f 0a 89 c3 83 f8 08 73 7a 49 bf RSP: 0018:ffffc90003e5f508 EFLAGS: 00000246 RAX: 0000000000000001 RBX: 0000000000000000 RCX: ffff888021acda00 RDX: 0000000000000000 RSI: 0000000005742a40 RDI: 000000ffffffffc0 RBP: 0000000000000560 R08: ffffffff820b709e R09: 1ffffffff285c100 R10: dffffc0000000000 R11: fffffbfff285c101 R12: 000000000015d0a9 R13: ffffea0005742a48 R14: ffffffff820b6fd0 R15: ffff88813a480000 rcu_read_lock_held_common kernel/rcu/update.c:109 [inline] rcu_read_lock_held+0x15/0x50 kernel/rcu/update.c:349 lookup_page_ext mm/page_ext.c:254 [inline] page_ext_get+0x192/0x2a0 mm/page_ext.c:526 __reset_page_owner+0x30/0x430 mm/page_owner.c:290 reset_page_owner include/linux/page_owner.h:25 [inline] free_pages_prepare mm/page_alloc.c:1108 [inline] free_unref_page+0xcfb/0xf20 mm/page_alloc.c:2638 discard_slab mm/slub.c:2677 [inline] __put_partials+0xeb/0x130 mm/slub.c:3145 put_cpu_partial+0x17c/0x250 mm/slub.c:3220 __slab_free+0x2ea/0x3d0 mm/slub.c:4449 qlink_free mm/kasan/quarantine.c:163 [inline] qlist_free_all+0x9a/0x140 mm/kasan/quarantine.c:179 kasan_quarantine_reduce+0x14f/0x170 mm/kasan/quarantine.c:286 __kasan_kmalloc+0x23/0xb0 mm/kasan/common.c:385 kasan_kmalloc include/linux/kasan.h:257 [inline] __do_kmalloc_node mm/slub.c:4264 [inline] __kmalloc_noprof+0x1fc/0x400 mm/slub.c:4276 kmalloc_noprof include/linux/slab.h:882 [inline] kzalloc_noprof include/linux/slab.h:1014 [inline] __register_sysctl_table+0x65/0x1550 fs/proc/proc_sysctl.c:1368 __addrconf_sysctl_register+0x234/0x3a0 net/ipv6/addrconf.c:7221 addrconf_sysctl_register+0x167/0x1c0 net/ipv6/addrconf.c:7269 ipv6_add_dev+0xcf6/0x1220 net/ipv6/addrconf.c:456 addrconf_notify+0x6a7/0x1020 net/ipv6/addrconf.c:3655 notifier_call_chain+0x19f/0x3e0 kernel/notifier.c:93 call_netdevice_notifiers_extack net/core/dev.c:2034 [inline] call_netdevice_notifiers net/core/dev.c:2048 [inline] register_netdevice+0x167f/0x1b00 net/core/dev.c:10626 ppp_unit_register drivers/net/ppp/ppp_generic.c:1219 [inline] ppp_dev_configure+0x883/0xb10 drivers/net/ppp/ppp_generic.c:1275 ppp_create_interface drivers/net/ppp/ppp_generic.c:3348 [inline] ppp_unattached_ioctl drivers/net/ppp/ppp_generic.c:1060 [inline] ppp_ioctl+0x797/0x1cd0 drivers/net/ppp/ppp_generic.c:733 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: 0033:0x7fd38957e719 RSP: 002b:00007fd38a2bb038 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: ffffffffffffffda RBX: 00007fd389735f80 RCX: 00007fd38957e719 RDX: 0000000020000100 RSI: 00000000c004743e RDI: 0000000000000009 RBP: 00007fd3895f1616 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fd389735f80 R15: 00007fff6a3fba98 rcu: rcu_preempt kthread starved for 10582 jiffies! g48393 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:25040 pid:17 tgid:17 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5328 [inline] __schedule+0x184f/0x4c30 kernel/sched/core.c:6690 __schedule_loop kernel/sched/core.c:6767 [inline] schedule+0x14b/0x320 kernel/sched/core.c:6782 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: CPU: 0 UID: 0 PID: 16 Comm: ksoftirqd/0 Not tainted 6.12.0-rc6-syzkaller-01362-ga58f00ed24b8 #0 Hardware name: Google Google Compute Engine/Google Compute Engine, BIOS Google 10/30/2024 RIP: 0010:preempt_count_add+0x44/0x190 kernel/sched/core.c:5799 Code: 00 00 00 fc ff df 42 0f b6 04 38 84 c0 0f 85 ed 00 00 00 83 3d 5c 4a db 18 00 75 07 65 8b 05 db a6 a0 7e 65 01 1d d4 a6 a0 7e <48> c7 c0 40 79 3e 9a 48 c1 e8 03 42 0f b6 04 38 84 c0 0f 85 e4 00 RSP: 0018:ffffc900001572d0 EFLAGS: 00000282 RAX: 0000000080000100 RBX: 0000000000000001 RCX: ffffffff9a3e7903 RDX: dffffc0000000000 RSI: ffffffff8ab2a7a2 RDI: 0000000000000001 RBP: ffffc900001573f8 R08: 0000000000000005 R09: ffffc900001574b0 R10: ffffc90000157410 R11: ffffffff818092c0 R12: dffffc0000000000 R13: ffffc900001573c0 R14: ffffffff8ab2a7a2 R15: dffffc0000000000 FS: 0000000000000000(0000) GS:ffff8880b8600000(0000) knlGS:0000000000000000 CS: 0010 DS: 0000 ES: 0000 CR0: 0000000080050033 CR2: 00005555867eb350 CR3: 000000000e734000 CR4: 00000000003526f0 DR0: 0000000000000000 DR1: 0000000000000000 DR2: 0000000000000000 DR3: 0000000000000000 DR6: 00000000fffe0ff0 DR7: 0000000000000400 Call Trace: unwind_next_frame+0xb0/0x22d0 arch/x86/kernel/unwind_orc.c:479 arch_stack_walk+0x11c/0x150 arch/x86/kernel/stacktrace.c:25 stack_trace_save+0x118/0x1d0 kernel/stacktrace.c:122 kasan_save_stack mm/kasan/common.c:47 [inline] kasan_save_track+0x3f/0x80 mm/kasan/common.c:68 unpoison_slab_object mm/kasan/common.c:319 [inline] __kasan_slab_alloc+0x66/0x80 mm/kasan/common.c:345 kasan_slab_alloc include/linux/kasan.h:247 [inline] slab_post_alloc_hook mm/slub.c:4085 [inline] slab_alloc_node mm/slub.c:4134 [inline] kmem_cache_alloc_node_noprof+0x16b/0x320 mm/slub.c:4186 __alloc_skb+0x1c3/0x440 net/core/skbuff.c:668 alloc_skb include/linux/skbuff.h:1323 [inline] bcm_can_tx+0x1fa/0x9a0 net/can/bcm.c:301 bcm_tx_timeout_handler+0x182/0x520 __run_hrtimer kernel/time/hrtimer.c:1691 [inline] __hrtimer_run_queues+0x59b/0xd50 kernel/time/hrtimer.c:1755 hrtimer_run_softirq+0x19a/0x2c0 kernel/time/hrtimer.c:1772 handle_softirqs+0x2c5/0x980 kernel/softirq.c:554 run_ksoftirqd+0xca/0x130 kernel/softirq.c:927 smpboot_thread_fn+0x544/0xa30 kernel/smpboot.c:164 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