======================================
| [   12.780836][    C1] 1 lock held by ksoftirqd/1/22:
| [ 12.781008][ C1] #0: ffffffff97f774c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   12.781320][    C1]
| [   12.781320][    C1] stack backtrace:
[   12.781542][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.781544][    C1] Call Trace:
[   12.781546][    C1]  <TASK>
[ 12.781548][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.781554][ C1] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 12.781559][ C1] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 12.781564][ C1] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 12.781569][ C1] ? save_trace (kernel/locking/lockdep.c:595) 
[ 12.781573][ C1] mark_lock (kernel/locking/lockdep.c:4756) 
[ 12.781577][ C1] mark_usage (kernel/locking/lockdep.c:4645) 
[ 12.781580][ C1] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 12.781584][ C1] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 12.781588][ C1] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 12.781591][ C1] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.781595][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.781600][ C1] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 12.781603][ C1] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.781606][ C1] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 12.781610][ C1] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.781612][ C1] simple_pin_fs (fs/libfs.c:1067) 
[ 12.781615][ C1] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 12.781619][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.781623][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.781626][ 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) 
[ 12.781631][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.781634][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.781636][ C1] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.781639][ C1] ? kthread (kernel/kthread.c:464) 
[ 12.781643][ C1] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.781646][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.781648][ 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) 
[ 12.781652][ C1] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 12.781658][ C1] __put_net (net/core/net_namespace.c:732) 
[ 12.781661][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.781666][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.781668][ C1] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.781673][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.781677][ C1] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.781680][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.781684][ C1] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 12.781688][ C1] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.781693][ C1] handle_softirqs (kernel/softirq.c:579) 
[ 12.781698][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 12.781702][ C1] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 12.781705][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.781707][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 12.781711][ C1] kthread (kernel/kthread.c:464) 
[ 12.781714][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.781716][ C1] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 12.781719][ C1] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.781722][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.781726][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.781729][ C1] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.781732][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.781734][ C1] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   12.792254][    C1] RCU nest depth: 0, expected: 0
| [   12.792421][    C1] INFO: lockdep is turned off.
| [   12.792579][    C1] Preemption disabled at:
| [ 12.792581][ C1] handle_softirqs (kernel/softirq.c:553) 
[   12.792904][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.792906][    C1] Call Trace:
[   12.792907][    C1]  <TASK>
[ 12.792909][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.792915][ C1] __might_resched (kernel/sched/core.c:8796) 
[ 12.792922][ C1] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 12.792926][ C1] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 12.792929][ C1] ? simple_recursive_removal (fs/libfs.c:614) 
[ 12.792933][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.792938][ 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) 
[ 12.792941][ C1] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 12.792944][ 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) 
[ 12.792947][ C1] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 12.792952][ C1] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 12.792955][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.792959][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.792962][ 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) 
[ 12.792966][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.792969][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.792971][ C1] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.792974][ C1] ? kthread (kernel/kthread.c:464) 
[ 12.792977][ C1] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.792981][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.792984][ 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) 
[ 12.792988][ C1] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 12.792994][ C1] __put_net (net/core/net_namespace.c:732) 
[ 12.792998][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.793002][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.793004][ C1] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.793009][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.793012][ C1] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.793017][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.793020][ C1] ? _raw_spin_unlock_irqrestore (./include/linux/spinlock_api_smp.h:151 kernel/locking/spinlock.c:194) 
[ 12.793026][ C1] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.793031][ C1] handle_softirqs (kernel/softirq.c:579) 
[ 12.793035][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 12.793040][ C1] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 12.793043][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.793046][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 12.793049][ C1] kthread (kernel/kthread.c:464) 
[ 12.793052][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.793054][ C1] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 12.793057][ C1] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.793061][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.793064][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.793067][ C1] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.793070][ 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