======================================
| [   12.948514][    C3] 1 lock held by ksoftirqd/3/32:
| [ 12.948688][ C3] #0: ffffffff903774c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   12.949009][    C3]
| [   12.949009][    C3] stack backtrace:
[   12.949229][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.949231][    C3] Call Trace:
[   12.949232][    C3]  <TASK>
[ 12.949235][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.949241][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 12.949245][ C3] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 12.949250][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 12.949255][ C3] ? save_trace (kernel/locking/lockdep.c:595) 
[ 12.949259][ C3] mark_lock (kernel/locking/lockdep.c:4756) 
[ 12.949263][ C3] mark_usage (kernel/locking/lockdep.c:4645) 
[ 12.949267][ C3] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 12.949270][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 12.949275][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 12.949278][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.949281][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.949287][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 12.949289][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.949293][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 12.949296][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.949299][ C3] simple_pin_fs (fs/libfs.c:1067) 
[ 12.949302][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 12.949305][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.949310][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.949312][ C3] ? __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) 
[ 12.949317][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.949320][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.949323][ C3] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.949326][ C3] ? kthread (kernel/kthread.c:464) 
[ 12.949329][ C3] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.949332][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.949335][ C3] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 12.949339][ C3] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 12.949344][ C3] __put_net (net/core/net_namespace.c:732) 
[ 12.949349][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.949353][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.949356][ C3] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.949361][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.949365][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.949368][ C3] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 12.949371][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.949377][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.949382][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 12.949386][ C3] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 12.949390][ C3] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 12.949393][ C3] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.949396][ C3] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 12.949399][ C3] kthread (kernel/kthread.c:464) 
[ 12.949402][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.949405][ C3] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 12.949407][ C3] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.949411][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.949414][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.949418][ C3] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.949420][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.949423][ C3] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   12.959900][    C3] RCU nest depth: 0, expected: 0
| [   12.960058][    C3] INFO: lockdep is turned off.
| [   12.960216][    C3] Preemption disabled at:
| [ 12.960218][ C3] handle_softirqs (kernel/softirq.c:553) 
[   12.960551][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.960552][    C3] Call Trace:
[   12.960554][    C3]  <TASK>
[ 12.960556][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.960561][ C3] __might_resched (kernel/sched/core.c:8796) 
[ 12.960568][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 12.960571][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 12.960574][ C3] ? simple_recursive_removal (fs/libfs.c:614) 
[ 12.960578][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.960582][ C3] ? 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) 
[ 12.960586][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 12.960589][ C3] ? 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) 
[ 12.960591][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 12.960597][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 12.960600][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:412 lib/ref_tracker.c:196) 
[ 12.960604][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:254) 
[ 12.960606][ C3] ? __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) 
[ 12.960611][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.960614][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:190) 
[ 12.960617][ C3] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.960619][ C3] ? kthread (kernel/kthread.c:464) 
[ 12.960621][ C3] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.960625][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.960628][ C3] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2427) 
[ 12.960632][ C3] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 12.960638][ C3] __put_net (net/core/net_namespace.c:732) 
[ 12.960641][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.960645][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.960648][ C3] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.960653][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.960657][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.960660][ C3] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 12.960663][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.960668][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.960673][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 12.960677][ C3] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 12.960681][ C3] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 12.960684][ C3] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.960687][ C3] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 12.960690][ C3] kthread (kernel/kthread.c:464) 
[ 12.960693][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.960696][ C3] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 12.960699][ C3] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.960703][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.960706][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.960709][ C3] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.960712][ C3] ? __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