rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P4651/1:b..l (detected by 0, t=10502 jiffies, g=11749, q=644) task:syz.0.109 state:R running task stack:22432 pid: 4651 ppid: 4167 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375 preempt_schedule_irq+0xf7/0x1c0 kernel/sched/core.c:6779 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 0c ac 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:ffffc9000150e6e0 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff920002a1ce8 RCX: 1ffff920002a1c88 RDX: dffffc0000000000 RSI: ffffffff8aab3d00 RDI: ffffffff8af9fa80 RBP: ffffc9000150e840 R08: dffffc0000000000 R09: fffffbfff2131e19 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff920002a1ce4 R13: dffffc0000000000 R14: ffffc9000150e740 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:6771 __mem_cgroup_charge+0x23/0x80 mm/memcontrol.c:6803 mem_cgroup_charge include/linux/memcontrol.h:700 [inline] __add_to_page_cache_locked+0xbdb/0x11a0 mm/filemap.c:892 add_to_page_cache_lru+0x1b3/0x560 mm/filemap.c:984 page_cache_ra_unbounded+0x403/0x930 mm/readahead.c:222 page_cache_async_readahead include/linux/pagemap.h:856 [inline] do_async_mmap_readahead mm/filemap.c:3023 [inline] filemap_fault+0x669/0x1470 mm/filemap.c:3079 __do_fault+0x139/0x340 mm/memory.c:3928 do_read_fault mm/memory.c:4264 [inline] do_fault mm/memory.c:4392 [inline] handle_pte_fault mm/memory.c:4650 [inline] __handle_mm_fault mm/memory.c:4785 [inline] handle_mm_fault+0x376f/0x5960 mm/memory.c:4883 faultin_page mm/gup.c:976 [inline] __get_user_pages+0x4ed/0x11d0 mm/gup.c:1197 __get_user_pages_locked mm/gup.c:1382 [inline] get_dump_page+0x1ad/0x8a0 mm/gup.c:1838 dump_user_range+0x64/0x320 fs/coredump.c:945 elf_core_dump+0x3c7d/0x4570 fs/binfmt_elf.c:2285 do_coredump+0x1852/0x31e0 fs/coredump.c:826 get_signal+0xc06/0x14e0 kernel/signal.c:2886 arch_do_signal_or_restart+0xc3/0x1890 arch/x86/kernel/signal.c:867 handle_signal_work kernel/entry/common.c:154 [inline] exit_to_user_mode_loop+0x97/0x130 kernel/entry/common.c:178 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:214 irqentry_exit_to_user_mode+0x5/0x30 kernel/entry/common.c:320 exc_page_fault+0x342/0x700 arch/x86/mm/fault.c:1504 asm_exc_page_fault+0x22/0x30 arch/x86/include/asm/idtentry.h:606 RIP: 0033:0x7faabd86e757 RSP: 002b:00007faabb7f7120 EFLAGS: 00010202 RAX: 0000000000000000 RBX: 000000000000000b RCX: 00007faabd9ad169 RDX: 00007faabb7f7140 RSI: 00007faabb7f7270 RDI: 000000000000000b RBP: 00007faabda2e2a0 R08: 0000000000000000 R09: 0000000000000000 R10: 0000000000000000 R11: 0000000000000206 R12: 0000000000000000 R13: 0000000000000000 R14: 00007faabdbc5fa0 R15: 00007fff417d4d98 rcu: rcu_preempt kthread starved for 9811 jiffies! g11749 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:27000 pid: 15 ppid: 2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5029 [inline] __schedule+0x12c4/0x45b0 kernel/sched/core.c:6375 schedule+0x11b/0x1f0 kernel/sched/core.c:6458 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 sched: RT throttling activated