======================================
| [   71.033620][    C3] 1 lock held by ksoftirqd/3/32:
| [ 71.033802][ C3] #0: ffffffff89b77c00 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   71.034122][    C3]
| [   71.034122][    C3] stack backtrace:
[   71.034351][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   71.034353][    C3] Call Trace:
[   71.034355][    C3]  <TASK>
[ 71.034358][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 71.034366][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 71.034371][ C3] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 71.034375][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 71.034382][ C3] ? save_trace (kernel/locking/lockdep.c:595) 
[ 71.034386][ C3] mark_lock (kernel/locking/lockdep.c:4756) 
[ 71.034391][ C3] mark_usage (kernel/locking/lockdep.c:4645) 
[ 71.034394][ C3] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 71.034398][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 71.034402][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 71.034406][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 71.034410][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 71.034417][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 71.034420][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 71.034424][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 71.034427][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 71.034431][ C3] simple_pin_fs (fs/libfs.c:1067) 
[ 71.034435][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 71.034438][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:411 lib/ref_tracker.c:195) 
[ 71.034444][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 71.034448][ 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) 
[ 71.034455][ C3] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 71.034458][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 71.034462][ C3] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 71.034466][ C3] ? kthread (kernel/kthread.c:464) 
[ 71.034470][ C3] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 71.034473][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 71.034476][ 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) 
[ 71.034480][ C3] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 71.034486][ C3] __put_net (net/core/net_namespace.c:732) 
[ 71.034490][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 71.034494][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 71.034497][ C3] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 71.034501][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 71.034505][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 71.034509][ C3] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 71.034512][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 71.034519][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 71.034523][ C3] handle_softirqs (kernel/softirq.c:580) 
[ 71.034527][ C3] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 71.034531][ C3] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 71.034535][ C3] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 71.034538][ C3] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 71.034541][ C3] kthread (kernel/kthread.c:464) 
[ 71.034544][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 71.034547][ C3] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 71.034550][ C3] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 71.034554][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 71.034557][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 71.034561][ C3] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 71.034564][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 71.034567][ C3] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   71.045109][    C3] RCU nest depth: 0, expected: 0
| [   71.045274][    C3] INFO: lockdep is turned off.
| [   71.045433][    C3] Preemption disabled at:
| [ 71.045435][ C3] handle_softirqs (kernel/softirq.c:553) 
[   71.045771][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   71.045773][    C3] Call Trace:
[   71.045775][    C3]  <TASK>
[ 71.045777][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 71.045783][ C3] __might_resched (kernel/sched/core.c:8796) 
[ 71.045789][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 71.045794][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 71.045797][ C3] ? simple_recursive_removal (fs/libfs.c:614) 
[ 71.045801][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 71.045807][ 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) 
[ 71.045812][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 71.045815][ 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) 
[ 71.045818][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 71.045823][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 71.045826][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:411 lib/ref_tracker.c:195) 
[ 71.045831][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 71.045835][ 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) 
[ 71.045841][ C3] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 71.045845][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 71.045848][ C3] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 71.045852][ C3] ? kthread (kernel/kthread.c:464) 
[ 71.045855][ C3] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 71.045859][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 71.045863][ 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) 
[ 71.045868][ C3] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 71.045873][ C3] __put_net (net/core/net_namespace.c:732) 
[ 71.045877][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 71.045881][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 71.045884][ C3] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2578) 
[ 71.045889][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 71.045894][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 71.045897][ C3] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 71.045900][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 71.045906][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 71.045910][ C3] handle_softirqs (kernel/softirq.c:580) 
[ 71.045914][ C3] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 71.045918][ C3] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 71.045922][ C3] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 71.045925][ C3] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 71.045928][ C3] kthread (kernel/kthread.c:464) 
[ 71.045932][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 71.045934][ C3] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 71.045937][ C3] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 71.045941][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 71.045945][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 71.045948][ C3] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 71.045952][ C3] ? __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