======================================
| [   12.588228][    C1] 1 lock held by ksoftirqd/1/22:
| [ 12.588401][ C1] #0: ffffffff9bb774c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   12.588710][    C1]
| [   12.588710][    C1] stack backtrace:
[   12.588930][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.588933][    C1] Call Trace:
[   12.588934][    C1]  <TASK>
[ 12.588937][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.588942][ C1] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 12.588947][ C1] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 12.588952][ C1] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 12.588957][ C1] ? save_trace (kernel/locking/lockdep.c:595) 
[ 12.588961][ C1] mark_lock (kernel/locking/lockdep.c:4756) 
[ 12.588965][ C1] mark_usage (kernel/locking/lockdep.c:4645) 
[ 12.588969][ C1] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 12.588972][ C1] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 12.588976][ C1] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 12.588980][ C1] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.588983][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.588989][ C1] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 12.588991][ C1] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.588995][ C1] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 12.588998][ C1] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.589001][ C1] simple_pin_fs (fs/libfs.c:1067) 
[ 12.589004][ C1] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 12.589007][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.589012][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.589015][ 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) 
[ 12.589020][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.589023][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.589026][ C1] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.589029][ C1] ? kthread (kernel/kthread.c:464) 
[ 12.589032][ C1] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.589035][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.589037][ 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) 
[ 12.589041][ C1] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 12.589047][ C1] __put_net (net/core/net_namespace.c:732) 
[ 12.589051][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.589055][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.589058][ C1] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.589061][ C1] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.589067][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.589071][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.589074][ C1] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 12.589077][ C1] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.589082][ C1] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.589087][ C1] handle_softirqs (kernel/softirq.c:579) 
[ 12.589091][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 12.589095][ C1] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 12.589098][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.589101][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 12.589104][ C1] kthread (kernel/kthread.c:464) 
[ 12.589107][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.589110][ C1] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 12.589113][ C1] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.589116][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.589120][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.589123][ C1] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.589126][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.589128][ C1] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   12.599639][    C1] RCU nest depth: 0, expected: 0
| [   12.599797][    C1] INFO: lockdep is turned off.
| [   12.599956][    C1] Preemption disabled at:
| [ 12.599958][ C1] handle_softirqs (kernel/softirq.c:553) 
[   12.600290][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.600292][    C1] Call Trace:
[   12.600293][    C1]  <TASK>
[ 12.600296][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.600302][ C1] __might_resched (kernel/sched/core.c:8796) 
[ 12.600309][ C1] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 12.600312][ C1] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 12.600315][ C1] ? simple_recursive_removal (fs/libfs.c:614) 
[ 12.600319][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.600323][ 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) 
[ 12.600327][ C1] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 12.600330][ 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) 
[ 12.600332][ C1] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 12.600338][ C1] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 12.600341][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.600344][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.600347][ 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) 
[ 12.600351][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.600354][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.600356][ C1] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.600359][ C1] ? kthread (kernel/kthread.c:464) 
[ 12.600362][ C1] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.600365][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.600368][ 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) 
[ 12.600372][ C1] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 12.600377][ C1] __put_net (net/core/net_namespace.c:732) 
[ 12.600381][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.600385][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.600388][ C1] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.600391][ C1] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.600396][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.600399][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.600403][ C1] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 12.600406][ C1] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.600410][ C1] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.600415][ C1] handle_softirqs (kernel/softirq.c:579) 
[ 12.600419][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 12.600423][ C1] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 12.600426][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.600429][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 12.600433][ C1] kthread (kernel/kthread.c:464) 
[ 12.600436][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.600438][ C1] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 12.600441][ C1] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.600446][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.600449][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.600453][ C1] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.600456][ C1] ? __pfx_kthread (kernel/kthread.c:413) 


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