======================================
| [   66.756713][    C1] 1 lock held by ksoftirqd/1/22:
| [ 66.756893][ C1] #0: ffffffffa1b77c00 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   66.757207][    C1]
| [   66.757207][    C1] stack backtrace:
[   66.757430][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   66.757435][    C1] Call Trace:
[   66.757438][    C1]  <TASK>
[ 66.757441][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 66.757452][ C1] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 66.757457][ C1] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 66.757462][ C1] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 66.757470][ C1] ? save_trace (kernel/locking/lockdep.c:595) 
[ 66.757474][ C1] mark_lock (kernel/locking/lockdep.c:4756) 
[ 66.757479][ C1] mark_usage (kernel/locking/lockdep.c:4645) 
[ 66.757482][ C1] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 66.757486][ C1] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 66.757491][ C1] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 66.757495][ C1] ? simple_pin_fs (fs/libfs.c:1067) 
[ 66.757499][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 66.757507][ C1] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 66.757510][ C1] ? simple_pin_fs (fs/libfs.c:1067) 
[ 66.757515][ C1] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 66.757518][ C1] ? simple_pin_fs (fs/libfs.c:1067) 
[ 66.757521][ C1] simple_pin_fs (fs/libfs.c:1067) 
[ 66.757526][ C1] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 66.757529][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 66.757538][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 66.757542][ C1] ? __sk_destruct (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/net_namespace.h:287 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 66.757554][ C1] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 66.757558][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 66.757561][ C1] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 66.757566][ C1] ? kthread (kernel/kthread.c:464) 
[ 66.757574][ C1] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 66.757577][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 66.757580][ C1] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 66.757586][ C1] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 66.757592][ C1] __put_net (net/core/net_namespace.c:732) 
[ 66.757600][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 66.757604][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 66.757608][ C1] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 66.757613][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 66.757617][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 66.757620][ C1] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 66.757624][ C1] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 66.757631][ C1] rcu_core (kernel/rcu/tree.c:2834) 
[ 66.757635][ C1] handle_softirqs (kernel/softirq.c:580) 
[ 66.757639][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 66.757644][ C1] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 66.757647][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 66.757650][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 66.757654][ C1] kthread (kernel/kthread.c:464) 
[ 66.757657][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 66.757660][ C1] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 66.757663][ C1] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 66.757667][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 66.757671][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 66.757674][ C1] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 66.757678][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 66.757681][ C1] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   66.768284][    C1] RCU nest depth: 0, expected: 0
| [   66.768448][    C1] INFO: lockdep is turned off.
| [   66.768604][    C1] Preemption disabled at:
| [ 66.768606][ C1] handle_softirqs (kernel/softirq.c:553) 
[   66.769016][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   66.769018][    C1] Call Trace:
[   66.769019][    C1]  <TASK>
[ 66.769021][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 66.769027][ C1] __might_resched (kernel/sched/core.c:8796) 
[ 66.769035][ C1] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 66.769039][ C1] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 66.769042][ C1] ? simple_recursive_removal (fs/libfs.c:614) 
[ 66.769046][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 66.769051][ C1] ? do_raw_spin_unlock (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/asm-generic/qspinlock.h:57 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141) 
[ 66.769055][ C1] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 66.769058][ C1] ? do_raw_spin_unlock (./arch/x86/include/asm/atomic.h:23 ./include/linux/atomic/atomic-arch-fallback.h:457 ./include/linux/atomic/atomic-instrumented.h:33 ./include/asm-generic/qspinlock.h:57 kernel/locking/spinlock_debug.c:101 kernel/locking/spinlock_debug.c:141) 
[ 66.769061][ C1] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 66.769066][ C1] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 66.769069][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 66.769074][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 66.769078][ C1] ? __sk_destruct (./include/linux/instrumented.h:96 ./include/linux/atomic/atomic-instrumented.h:400 ./include/linux/refcount.h:389 ./include/linux/refcount.h:432 ./include/linux/refcount.h:450 ./include/net/net_namespace.h:287 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 66.769082][ C1] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 66.769086][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 66.769090][ C1] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 66.769093][ C1] ? kthread (kernel/kthread.c:464) 
[ 66.769097][ C1] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 66.769101][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 66.769105][ C1] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 66.769110][ C1] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 66.769115][ C1] __put_net (net/core/net_namespace.c:732) 
[ 66.769119][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 66.769123][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 66.769126][ C1] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 66.769131][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 66.769135][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 66.769139][ C1] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 66.769142][ C1] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 66.769148][ C1] rcu_core (kernel/rcu/tree.c:2834) 
[ 66.769151][ C1] handle_softirqs (kernel/softirq.c:580) 
[ 66.769156][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 66.769160][ C1] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 66.769164][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 66.769167][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 66.769170][ C1] kthread (kernel/kthread.c:464) 
[ 66.769174][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 66.769176][ C1] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 66.769179][ C1] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 66.769184][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 66.769188][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 66.769191][ C1] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 66.769194][ C1] ? __pfx_kthread (kernel/kthread.c:413) 


Finger prints:
mark_lock_irq:mark_lock:mark_usage:__lock_acquire:_raw_spin_lock
handle_softirqs:dump_stack_lvl:__might_resched:down_write:simple_recursive_removal