rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5908/1:b..l P4275/1:b..l (detected by 0, t=10502 jiffies, g=15541, q=65) task:kworker/u4:9 state:R running task stack:20152 pid: 4275 ppid: 2 flags:0x00004000 Workqueue: bat_events batadv_nc_worker Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_notrace+0xf8/0x140 kernel/sched/core.c:6628 preempt_schedule_notrace_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:35 rcu_is_watching+0x72/0xa0 kernel/rcu/tree.c:1124 rcu_read_unlock include/linux/rcupdate.h:768 [inline] batadv_nc_purge_orig_hash net/batman-adv/network-coding.c:416 [inline] batadv_nc_worker+0x1ce/0x5b0 net/batman-adv/network-coding.c:723 process_one_work+0x8a1/0x10c0 kernel/workqueue.c:2310 worker_thread+0xaca/0x1280 kernel/workqueue.c:2457 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 task:syz.4.327 state:R running task stack:25760 pid: 5908 ppid: 4177 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6777 irqentry_exit+0x53/0x80 kernel/entry/common.c:432 asm_sysvec_apic_timer_interrupt+0x16/0x20 arch/x86/include/asm/idtentry.h:676 RIP: 0010:lock_acquire+0x252/0x4f0 kernel/locking/lockdep.c:5627 Code: 2b 00 74 08 4c 89 f7 e8 fc 8c 67 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:ffffc900033d7080 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff9200067ae1c RCX: 1ffff9200067adbc RDX: dffffc0000000000 RSI: ffffffff8aab3d20 RDI: ffffffff8af9ed00 RBP: ffffc900033d71e0 R08: dffffc0000000000 R09: fffffbfff2131021 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff9200067ae18 R13: dffffc0000000000 R14: ffffc900033d70e0 R15: 0000000000000246 rcu_lock_acquire+0x20/0x30 include/linux/rcupdate.h:312 rcu_read_lock include/linux/rcupdate.h:739 [inline] percpu_ref_get_many+0x15/0x110 include/linux/percpu-refcount.h:202 percpu_ref_get include/linux/percpu-refcount.h:222 [inline] css_get include/linux/cgroup.h:325 [inline] charge_memcg+0x145/0x340 mm/memcontrol.c:6766 __mem_cgroup_charge+0x23/0x80 mm/memcontrol.c:6798 mem_cgroup_charge include/linux/memcontrol.h:700 [inline] shmem_add_to_page_cache+0xc22/0x17c0 mm/shmem.c:718 shmem_getpage_gfp+0x1aa1/0x3190 mm/shmem.c:1942 shmem_fault+0x1d7/0x700 mm/shmem.c:2120 __do_fault+0x139/0x340 mm/memory.c:3926 do_read_fault mm/memory.c:4262 [inline] do_fault mm/memory.c:4390 [inline] handle_pte_fault mm/memory.c:4648 [inline] __handle_mm_fault mm/memory.c:4783 [inline] handle_mm_fault+0x376f/0x5960 mm/memory.c:4881 faultin_page mm/gup.c:976 [inline] __get_user_pages+0x4ed/0x11d0 mm/gup.c:1197 populate_vma_page_range+0x215/0x2a0 mm/gup.c:1529 __mm_populate+0x2a5/0x4a0 mm/gup.c:1638 mm_populate include/linux/mm.h:2632 [inline] vm_mmap_pgoff+0x22b/0x2d0 mm/util.c:556 ksys_mmap_pgoff+0x13e/0x780 mm/mmap.c:1624 do_syscall_x64 arch/x86/entry/common.c:50 [inline] do_syscall_64+0x3b/0xb0 arch/x86/entry/common.c:80 entry_SYSCALL_64_after_hwframe+0x66/0xd0 RIP: 0033:0x7fbbe1845f19 RSP: 002b:00007fbbdf69b058 EFLAGS: 00000246 ORIG_RAX: 0000000000000009 RAX: ffffffffffffffda RBX: 00007fbbe1a0c080 RCX: 00007fbbe1845f19 RDX: b635773f06ebbeee RSI: 0000000000b36000 RDI: 0000000020000000 RBP: 00007fbbe18b9986 R08: ffffffffffffffff R09: 0000000000000000 R10: 0000000000008031 R11: 0000000000000246 R12: 0000000000000000 R13: 0000000000000000 R14: 00007fbbe1a0c080 R15: 00007ffdd5961888 rcu: rcu_preempt kthread starved for 10557 jiffies! g15541 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:27064 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5027 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6373 schedule+0x11b/0x1f0 kernel/sched/core.c:6456 schedule_timeout+0x1b9/0x300 kernel/time/timer.c:1914 rcu_gp_fqs_loop+0x2bf/0x1080 kernel/rcu/tree.c:1972 rcu_gp_kthread+0xa4/0x360 kernel/rcu/tree.c:2145 kthread+0x3f6/0x4f0 kernel/kthread.c:334 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:287 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:108 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:562