rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: rcu: Tasks blocked on level-0 rcu_node (CPUs 0-1): P5095/1:b..l P5216/1:b..l rcu: (detected by 0, t=10502 jiffies, g=15549, q=757 ncpus=2) task:udevd state:R running task stack:26456 pid:5216 tgid:5216 ppid:4524 flags:0x00000002 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6746 preempt_schedule_common+0x44/0xc0 kernel/sched/core.c:6925 preempt_schedule_thunk+0x1a/0x30 arch/x86/entry/thunk_64.S:12 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:152 [inline] _raw_spin_unlock_irqrestore+0x61/0x80 kernel/locking/spinlock.c:194 sock_def_readable+0x160/0x7a0 net/core/sock.c:3354 unix_dgram_sendmsg+0xff6/0x1b10 net/unix/af_unix.c:2159 sock_sendmsg_nosec net/socket.c:730 [inline] __sock_sendmsg net/socket.c:745 [inline] sock_write_iter+0x50a/0x5c0 net/socket.c:1160 call_write_iter include/linux/fs.h:2110 [inline] new_sync_write fs/read_write.c:497 [inline] vfs_write+0x6db/0x1100 fs/read_write.c:590 ksys_write+0x1f8/0x260 fs/read_write.c:643 do_syscall_x64 arch/x86/entry/common.c:52 [inline] do_syscall_64+0xcf/0x260 arch/x86/entry/common.c:83 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f49c4f16bf2 RSP: 002b:00007ffcfa274aa8 EFLAGS: 00000246 ORIG_RAX: 0000000000000001 RAX: ffffffffffffffda RBX: 0000000000000000 RCX: 00007f49c4f16bf2 RDX: 0000000000000000 RSI: 00007ffcfa274aff RDI: 000000000000000a RBP: 00007ffcfa274aff R08: 0000000000000001 R09: 0000000000000000 R10: 000000000000010f R11: 0000000000000246 R12: 000000000000000a R13: 00007f49c53c5ae0 R14: 0000000000000000 R15: 000055f2d651e2c0 task:syz-executor.3 state:R running task stack:22928 pid:5095 tgid:5095 ppid:5084 flags:0x00004002 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6746 preempt_schedule_irq+0x51/0x90 kernel/sched/core.c:7068 irqentry_exit+0x36/0x90 kernel/entry/common.c:354 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:702 RIP: 0010:lock_acquire+0x1f2/0x560 kernel/locking/lockdep.c:5722 Code: c1 05 ca 9f 96 7e 83 f8 01 0f 85 ea 02 00 00 9c 58 f6 c4 02 0f 85 d5 02 00 00 48 85 ed 74 01 fb 48 b8 00 00 00 00 00 fc ff df <48> 01 c3 48 c7 03 00 00 00 00 48 c7 43 08 00 00 00 00 48 8b 84 24 RSP: 0018:ffffc900032ff4f0 EFLAGS: 00000206 RAX: dffffc0000000000 RBX: 1ffff9200065fea0 RCX: 00000000d439196c RDX: 0000000000000001 RSI: ffffffff8b0cb100 RDI: ffffffff8b6f6c60 RBP: 0000000000000200 R08: 0000000000000000 R09: fffffbfff27bb630 R10: ffffffff93ddb187 R11: 0000000000000000 R12: 0000000000000000 R13: 0000000000000000 R14: ffffffff8d7b0e20 R15: 0000000000000000 rcu_lock_acquire include/linux/rcupdate.h:329 [inline] rcu_read_lock include/linux/rcupdate.h:781 [inline] percpu_ref_put_many.constprop.0+0x2f/0x1b0 include/linux/percpu-refcount.h:330 __mem_cgroup_uncharge_folios+0x11c/0x1e0 mm/memcontrol.c:7523 mem_cgroup_uncharge_folios include/linux/memcontrol.h:721 [inline] folios_put_refs+0x48f/0x750 mm/swap.c:1033 folio_batch_release include/linux/pagevec.h:101 [inline] shmem_undo_range+0x5a1/0x1170 mm/shmem.c:1005 shmem_truncate_range mm/shmem.c:1114 [inline] shmem_evict_inode+0x3a3/0xbb0 mm/shmem.c:1242 evict+0x2ed/0x6c0 fs/inode.c:667 iput_final fs/inode.c:1741 [inline] iput.part.0+0x5a8/0x7f0 fs/inode.c:1767 iput+0x5c/0x80 fs/inode.c:1757 dentry_unlink_inode+0x295/0x440 fs/dcache.c:400 __dentry_kill+0x1d0/0x600 fs/dcache.c:603 dput.part.0+0x4b1/0x9b0 fs/dcache.c:845 dput+0x1f/0x30 fs/dcache.c:835 __fput+0x3bc/0xb80 fs/file_table.c:430 task_work_run+0x14e/0x250 kernel/task_work.c:180 resume_user_mode_work include/linux/resume_user_mode.h:50 [inline] exit_to_user_mode_loop kernel/entry/common.c:114 [inline] exit_to_user_mode_prepare include/linux/entry-common.h:328 [inline] __syscall_exit_to_user_mode_work kernel/entry/common.c:207 [inline] syscall_exit_to_user_mode+0x278/0x2a0 kernel/entry/common.c:218 do_syscall_64+0xdc/0x260 arch/x86/entry/common.c:89 entry_SYSCALL_64_after_hwframe+0x77/0x7f RIP: 0033:0x7f87db67dc0b RSP: 002b:00007ffdd07f10f0 EFLAGS: 00000246 ORIG_RAX: 0000000000000010 RAX: 0000000000000000 RBX: 0000000000000003 RCX: 00007f87db67dc0b RDX: 0000000000000000 RSI: 0000000000004c01 RDI: 0000000000000003 RBP: 00007ffdd07f11ac R08: 0000000000000000 R09: 00007ffdd07f0e97 R10: 0000000000000000 R11: 0000000000000246 R12: 0000000000000032 R13: 0000000000025979 R14: 0000000000025287 R15: 0000000000000007 rcu: rcu_preempt kthread starved for 10530 jiffies! g15549 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:27568 pid:16 tgid:16 ppid:2 flags:0x00004000 Call Trace: context_switch kernel/sched/core.c:5409 [inline] __schedule+0xf15/0x5d00 kernel/sched/core.c:6746 __schedule_loop kernel/sched/core.c:6823 [inline] schedule+0xe7/0x350 kernel/sched/core.c:6838 schedule_timeout+0x136/0x2a0 kernel/time/timer.c:2582 rcu_gp_fqs_loop+0x1eb/0xb00 kernel/rcu/tree.c:1663 rcu_gp_kthread+0x271/0x380 kernel/rcu/tree.c:1862 kthread+0x2c1/0x3a0 kernel/kthread.c:388 ret_from_fork+0x45/0x80 arch/x86/kernel/process.c:147 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:244 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:48 [inline] NMI backtrace for cpu 1 skipped: idling at arch_safe_halt arch/x86/include/asm/irqflags.h:86 [inline] NMI backtrace for cpu 1 skipped: idling at acpi_safe_halt+0x1a/0x20 drivers/acpi/processor_idle.c:112 sched: RT throttling activated