rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P3850/1:b..l P4875/1:b..l (detected by 0, t=10502 jiffies, g=20173, q=631 ncpus=2) task:ext4lazyinit state:R running task stack:26816 pid:4875 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 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 3f ac 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:ffffc90004c0f780 EFLAGS: 00000206 RAX: 0000000000000001 RBX: 1ffff92000981efc RCX: 1ffff92000981e9c RDX: dffffc0000000000 RSI: ffffffff8b0c14c0 RDI: ffffffff8b5d6dc0 RBP: ffffc90004c0f8c8 R08: dffffc0000000000 R09: fffffbfff223b845 R10: 0000000000000000 R11: dffffc0000000001 R12: 1ffff92000981ef8 R13: dffffc0000000000 R14: ffffc90004c0f7e0 R15: 0000000000000246 rcu_lock_acquire include/linux/rcupdate.h:350 [inline] rcu_read_lock include/linux/rcupdate.h:791 [inline] mapping_get_entry mm/filemap.c:1850 [inline] __filemap_get_folio+0x171/0xe80 mm/filemap.c:1915 pagecache_get_page+0x28/0x250 mm/folio-compat.c:110 find_get_page_flags include/linux/pagemap.h:602 [inline] __find_get_block_slow fs/buffer.c:202 [inline] __find_get_block+0x3d8/0x1120 fs/buffer.c:1307 __getblk_slow fs/buffer.c:1034 [inline] __getblk_gfp+0x146/0xa20 fs/buffer.c:1333 sb_getblk include/linux/buffer_head.h:356 [inline] ext4_read_block_bitmap_nowait+0x1ff/0x980 fs/ext4/balloc.c:482 ext4_mb_prefetch+0x46d/0x640 fs/ext4/mballoc.c:2587 ext4_run_li_request fs/ext4/super.c:3655 [inline] ext4_lazyinit_thread+0x54d/0x1ad0 fs/ext4/super.c:3781 kthread+0x28d/0x320 kernel/kthread.c:376 ret_from_fork+0x1f/0x30 arch/x86/entry/entry_64.S:295 task:kworker/u4:13 state:R running task stack:21464 pid:3850 ppid:2 flags:0x00004000 Workqueue: bat_events batadv_mcast_mla_update Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 kernel/sched/core.c:6558 preempt_schedule_common+0x83/0xd0 kernel/sched/core.c:6727 preempt_schedule+0xd9/0xe0 kernel/sched/core.c:6751 preempt_schedule_thunk+0x16/0x18 arch/x86/entry/thunk_64.S:34 irq_work_queue+0xe7/0x150 kernel/irq_work.c:115 __kfence_alloc+0x226/0x370 mm/kfence/core.c:1024 kfence_alloc include/linux/kfence.h:128 [inline] slab_alloc_node mm/slub.c:3322 [inline] __kmem_cache_alloc_node+0x1fa/0x260 mm/slub.c:3437 kmalloc_trace+0x26/0xe0 mm/slab_common.c:1026 kmalloc include/linux/slab.h:557 [inline] batadv_mcast_mla_softif_get_ipv4 net/batman-adv/multicast.c:374 [inline] batadv_mcast_mla_softif_get net/batman-adv/multicast.c:501 [inline] __batadv_mcast_mla_update net/batman-adv/multicast.c:879 [inline] batadv_mcast_mla_update+0xbd7/0x3c80 net/batman-adv/multicast.c:916 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:295 rcu: rcu_preempt kthread starved for 9569 jiffies! g20173 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:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5241 [inline] __schedule+0x143f/0x4570 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:295 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:111 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_idle_do_entry+0x10f/0x340 drivers/acpi/processor_idle.c:567