rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P6131/1:b..l P6129/1:b..l (detected by 0, t=10502 jiffies, g=19117, q=105 ncpus=2) task:syz.2.542 state:R running task stack:24872 pid:6129 ppid:4249 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:691 RIP: 0010:unwind_get_return_address+0x52/0x80 arch/x86/kernel/unwind_orc.c:323 Code: 83 c3 48 49 89 df 49 c1 ef 03 43 80 3c 37 00 74 08 48 89 df e8 6f 5b a5 00 48 8b 3b e8 47 d4 1e 00 85 c0 74 14 43 80 3c 37 00 <74> 08 48 89 df e8 54 5b a5 00 48 8b 03 eb 02 31 c0 5b 41 5e 41 5f RSP: 0018:ffffc9000d51f080 EFLAGS: 00000246 RAX: 0000000000000001 RBX: ffffc9000d51f0e8 RCX: ffffffff8fdd3000 RDX: ffffffff8ff2d701 RSI: ffffc9000d518000 RDI: ffffffff81d159dc RBP: ffffc9000d51f130 R08: ffffc9000d51f620 R09: ffffc9000d51f0f0 R10: 0000000000000000 R11: dffffc0000000001 R12: ffff888027719dc0 R13: ffffffff81785880 R14: dffffc0000000000 R15: 1ffff92001aa3e1d arch_stack_walk+0xf3/0x140 arch/x86/kernel/stacktrace.c:26 stack_trace_save+0x113/0x1c0 kernel/stacktrace.c:122 save_stack+0xf6/0x1e0 mm/page_owner.c:127 __reset_page_owner+0x52/0x1a0 mm/page_owner.c:148 reset_page_owner include/linux/page_owner.h:24 [inline] free_pages_prepare mm/page_alloc.c:1459 [inline] free_pcp_prepare mm/page_alloc.c:1509 [inline] free_unref_page_prepare+0x12a6/0x15b0 mm/page_alloc.c:3384 free_unref_page_list+0x663/0x900 mm/page_alloc.c:3525 release_pages+0x24c4/0x27a0 mm/swap.c:1035 tlb_batch_pages_flush mm/mmu_gather.c:59 [inline] tlb_flush_mmu_free mm/mmu_gather.c:254 [inline] tlb_flush_mmu+0xfc/0x210 mm/mmu_gather.c:261 tlb_finish_mmu+0xce/0x1f0 mm/mmu_gather.c:361 exit_mmap+0x3b3/0x980 mm/mmap.c:3250 __mmput+0x115/0x3c0 kernel/fork.c:1200 exit_mm+0x226/0x300 kernel/exit.c:565 do_exit+0x9f1/0x26a0 kernel/exit.c:858 do_group_exit+0x202/0x2b0 kernel/exit.c:1021 get_signal+0x16f7/0x17d0 kernel/signal.c:2871 arch_do_signal_or_restart+0xb0/0x1a10 arch/x86/kernel/signal.c:871 exit_to_user_mode_loop+0x6a/0x100 kernel/entry/common.c:174 exit_to_user_mode_prepare+0xb1/0x140 kernel/entry/common.c:210 __syscall_exit_to_user_mode_work kernel/entry/common.c:292 [inline] syscall_exit_to_user_mode+0x60/0x270 kernel/entry/common.c:303 do_syscall_64+0x47/0xb0 arch/x86/entry/common.c:87 entry_SYSCALL_64_after_hwframe+0x68/0xd2 RIP: 0033:0x7f6f90785d29 RSP: 002b:00007f6f916000e8 EFLAGS: 00000246 ORIG_RAX: 00000000000000ca RAX: 0000000000000001 RBX: 00007f6f90975fa8 RCX: 00007f6f90785d29 RDX: 00000000000f4240 RSI: 0000000000000081 RDI: 00007f6f90975fac RBP: 00007f6f90975fa0 R08: 0000000000000010 R09: 0000000000000000 R10: 000000000000004c R11: 0000000000000246 R12: 00007f6f90975fac R13: 0000000000000000 R14: 00007fff2875e140 R15: 00007fff2875e228 task:syz.1.541 state:R running task stack:25528 pid:6131 ppid:4254 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_reschedule_ipi+0x16/0x20 arch/x86/include/asm/idtentry.h:696 RIP: 0010:blk_cgroup_congested+0xeb/0x220 Code: 00 48 89 c5 49 bf 00 00 00 00 00 fc ff df 41 bc b8 09 00 00 48 89 e8 48 c1 e8 03 42 80 3c 38 00 74 08 48 89 ef e8 65 60 b1 fd <48> 8b 5d 00 4c 01 e3 48 89 df be 04 00 00 00 e8 e1 61 b1 fd 48 89 RSP: 0018:ffffc9000d4c7638 EFLAGS: 00000246 RAX: 1ffff1102995e200 RBX: 0000000000000001 RCX: 0000000000080000 RDX: ffffc90005699000 RSI: 00000000000046cc RDI: 00000000000046cd RBP: ffff88814caf1000 R08: ffffffff8430b20a R09: fffffbfff2249c4d R10: 0000000000000000 R11: dffffc0000000001 R12: 00000000000009b8 R13: ffffc9000d4c7778 R14: ffffffff8430ce79 R15: dffffc0000000000 __cgroup_throttle_swaprate+0x6d/0x1b0 mm/swapfile.c:3671 cgroup_throttle_swaprate include/linux/swap.h:662 [inline] folio_throttle_swaprate include/linux/swap.h:671 [inline] shmem_add_to_page_cache+0xb90/0x1e60 mm/shmem.c:717 shmem_get_folio_gfp+0x164e/0x3470 mm/shmem.c:1971 shmem_get_folio mm/shmem.c:2072 [inline] shmem_write_begin+0x16e/0x4e0 mm/shmem.c:2556 generic_perform_write+0x2fc/0x5e0 mm/filemap.c:3845 __generic_file_write_iter+0x176/0x400 mm/filemap.c:3973 generic_file_write_iter+0xab/0x310 mm/filemap.c:4005 call_write_iter include/linux/fs.h:2265 [inline] new_sync_write fs/read_write.c:491 [inline] vfs_write+0x857/0xbc0 fs/read_write.c:584 ksys_write+0x19c/0x2c0 fs/read_write.c:637 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: 0033:0x7f2ca35847df RSP: 002b:00007f2ca33fedf0 EFLAGS: 00000293 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000040000 RCX: 00007f2ca35847df RDX: 0000000000040000 RSI: 00007f2c98df7000 RDI: 0000000000000003 RBP: 0000000000000000 R08: 0000000000000000 R09: 000000000000047f R10: 00000000000003ba R11: 0000000000000293 R12: 0000000000000003 R13: 00007f2ca33feef0 R14: 00007f2ca33feeb0 R15: 00007f2c98df7000 rcu: rcu_preempt kthread starved for 10587 jiffies! g19117 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:26712 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