rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5897/1:b..l P4927/1:b..l (detected by 0, t=10502 jiffies, g=26633, q=266 ncpus=2) task:kworker/u4:10 state:R running task stack:23864 pid:4927 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:lock_acquire+0x26f/0x5a0 kernel/locking/lockdep.c:5666 Code: 2b 00 74 08 4c 89 f7 e8 ef ae 77 00 f6 44 24 61 02 0f 85 84 01 00 00 41 f7 c7 00 02 00 00 74 01 fb 48 c7 44 24 40 0e 36 e0 45 <4b> c7 44 25 00 00 00 00 00 43 c7 44 25 09 00 00 00 00 43 c7 44 25 RSP: 0018:ffffc9000aaf7a20 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200155ef50 RCX: 1ffff9200155eef0 RDX: dffffc0000000000 RSI: ffffffff8aec13c0 RDI: ffffffff8b3d47e0 RBP: ffffc9000aaf7b70 R08: dffffc0000000000 R09: fffffbfff2093845 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200155ef4c R13: dffffc0000000000 R14: ffffc9000aaf7a80 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] batadv_nc_process_nc_paths+0xd6/0x390 net/batman-adv/network-coding.c:687 batadv_nc_worker+0x426/0x610 net/batman-adv/network-coding.c:728 process_one_work+0x8a9/0x11d0 kernel/workqueue.c:2292 worker_thread+0xa47/0x1200 kernel/workqueue.c:2439 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 task:syz.0.488 state:R running task stack:23688 pid:5897 ppid:3547 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6870 irqentry_exit+0x53/0x80 kernel/entry/common.c:439 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:653 RIP: 0010:lookup_page_ext mm/page_ext.c:275 [inline] RIP: 0010:page_ext_get+0x17c/0x2a0 mm/page_ext.c:158 Code: 83 e5 7f 48 c1 e5 05 48 01 eb eb 0e e8 8d d4 9d ff eb 05 e8 86 d4 9d ff 31 db 48 83 c3 10 48 89 d8 48 c1 e8 03 42 80 3c 38 00 <74> 08 48 89 df e8 2a 58 f5 ff 4c 8b 3b e8 92 58 85 ff 89 c3 31 ff RSP: 0018:ffffc900055fed98 EFLAGS: 00000246 RAX: 1ffff11027fff22e RBX: ffff88813fff9170 RCX: 0000000000040000 RDX: ffffc90003d01000 RSI: 000000000003ffff RDI: 0000000000040000 RBP: 0000000000000160 R08: ffffffff81ecc14a R09: fffffbfff2093845 R10: 0000000000000000 R11: dffffc0000000001 R12: 000000000005c6cd R13: 0000000000000000 R14: ffffffff81ecc07c R15: dffffc0000000000 __set_page_owner+0x32/0x390 mm/page_owner.c:192 set_page_owner include/linux/page_owner.h:31 [inline] post_alloc_hook+0x18d/0x1b0 mm/page_alloc.c:2517 prep_new_page mm/page_alloc.c:2524 [inline] get_page_from_freelist+0x322e/0x33b0 mm/page_alloc.c:4283 __alloc_pages+0x28d/0x770 mm/page_alloc.c:5551 __folio_alloc+0xf/0x30 mm/page_alloc.c:5583 vma_alloc_folio+0x486/0x990 mm/mempolicy.c:2243 shmem_alloc_folio mm/shmem.c:1589 [inline] shmem_alloc_and_acct_folio+0x5a8/0xd50 mm/shmem.c:1613 shmem_get_folio_gfp+0x13f0/0x3470 mm/shmem.c:1941 shmem_fault+0x235/0x9c0 mm/shmem.c:2156 __do_fault+0x136/0x4f0 mm/memory.c:4261 do_read_fault mm/memory.c:4612 [inline] do_fault mm/memory.c:4741 [inline] handle_pte_fault mm/memory.c:5013 [inline] __handle_mm_fault mm/memory.c:5155 [inline] handle_mm_fault+0x3412/0x5340 mm/memory.c:5276 faultin_page mm/gup.c:1009 [inline] __get_user_pages+0x4f3/0x1190 mm/gup.c:1233 populate_vma_page_range+0x217/0x2b0 mm/gup.c:1590 __mm_populate+0x275/0x440 mm/gup.c:1704 mm_populate include/linux/mm.h:2797 [inline] vm_mmap_pgoff+0x22b/0x2d0 mm/util.c:525 do_syscall_x64 arch/x86/entry/common.c:51 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:81 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f0f5bb75a19 RSP: 002b:00007f0f5c98b048 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007f0f5bd03f60 RCX: 00007f0f5bb75a19 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007f0f5bbe4e49 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 000000000000000b R14: 00007f0f5bd03f60 R15: 00007ffd38bee7d8 rcu: rcu_preempt kthread starved for 9905 jiffies! g26633 f0x0 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:25272 pid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5245 [inline] __schedule+0x142d/0x4550 kernel/sched/core.c:6558 schedule+0xbf/0x180 kernel/sched/core.c:6634 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1965 rcu_gp_fqs_loop+0x2d2/0x1150 kernel/rcu/tree.c:1706 rcu_gp_kthread+0xa3/0x3b0 kernel/rcu/tree.c:1905 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:308 rcu: Stack dump where RCU GP kthread last ran: Sending NMI from CPU 0 to CPUs 1: NMI backtrace for cpu 1 skipped: idling at native_safe_halt arch/x86/include/asm/irqflags.h:51 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:89 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt drivers/acpi/processor_idle.c:112 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:572 vkms_vblank_simulate: vblank timer overrun