======================================
| [   13.727347][    C1] 1 lock held by ksoftirqd/1/22:
| [ 13.727524][ C1] #0: ffffffff87b749c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2562) 
| [   13.727840][    C1]
| [   13.727840][    C1] stack backtrace:
[   13.728080][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   13.728082][    C1] Call Trace:
[   13.728083][    C1]  <TASK>
[ 13.728086][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 13.728092][ C1] print_usage_bug.part.0 (kernel/locking/lockdep.c:4046) 
[ 13.728097][ C1] mark_lock_irq (kernel/locking/lockdep.c:4011 kernel/locking/lockdep.c:4057 kernel/locking/lockdep.c:4268) 
[ 13.728101][ C1] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 13.728106][ C1] ? save_trace (kernel/locking/lockdep.c:594) 
[ 13.728111][ C1] mark_lock (kernel/locking/lockdep.c:4754) 
[ 13.728115][ C1] mark_usage (kernel/locking/lockdep.c:4643) 
[ 13.728118][ C1] __lock_acquire (kernel/locking/lockdep.c:5189) 
[ 13.728122][ C1] lock_acquire.part.0 (kernel/locking/lockdep.c:472 kernel/locking/lockdep.c:5868) 
[ 13.728125][ C1] ? simple_pin_fs (fs/libfs.c:1066) 
[ 13.728129][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.728132][ C1] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5829) 
[ 13.728134][ C1] ? simple_pin_fs (fs/libfs.c:1066) 
[ 13.728138][ C1] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 13.728141][ C1] ? simple_pin_fs (fs/libfs.c:1066) 
[ 13.728144][ C1] simple_pin_fs (fs/libfs.c:1066) 
[ 13.728147][ C1] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 13.728150][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 13.728156][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 13.728160][ 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:2366) 
[ 13.728164][ C1] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 13.728168][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 13.728171][ C1] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 13.728177][ C1] ? kthread (kernel/kthread.c:464) 
[ 13.728181][ C1] ? ret_from_fork (arch/x86/kernel/process.c:153) 
[ 13.728184][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 13.728187][ C1] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2417) 
[ 13.728191][ C1] ? __pfx_migrate_enable (kernel/sched/core.c:2392) 
[ 13.728196][ C1] __put_net (net/core/net_namespace.c:732) 
[ 13.728200][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 13.728204][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 13.728207][ C1] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 13.728213][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 13.728217][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.728220][ C1] ? note_gp_changes (kernel/rcu/tree.c:1324 (discriminator 1)) 
[ 13.728222][ C1] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 13.728228][ C1] rcu_core (kernel/rcu/tree.c:2826) 
[ 13.728232][ C1] handle_softirqs (kernel/softirq.c:579) 
[ 13.728236][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 13.728240][ C1] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 13.728242][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 13.728246][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 13.728250][ C1] kthread (kernel/kthread.c:464) 
[ 13.728254][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.728257][ C1] ? ret_from_fork (arch/x86/kernel/process.c:152) 
[ 13.728259][ C1] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 13.728262][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.728265][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.728269][ C1] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 13.728271][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.728275][ C1] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   13.739397][    C1] RCU nest depth: 0, expected: 0
| [   13.739577][    C1] INFO: lockdep is turned off.
| [   13.739757][    C1] Preemption disabled at:
| [ 13.739759][ C1] handle_softirqs (kernel/softirq.c:553) 
[   13.740122][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   13.740124][    C1] Call Trace:
[   13.740126][    C1]  <TASK>
[ 13.740129][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 13.740136][ C1] __might_resched (kernel/sched/core.c:8819) 
[ 13.740143][ C1] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 13.740147][ C1] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 13.740149][ C1] ? simple_recursive_removal (./include/linux/dcache.h:345 fs/libfs.c:610) 
[ 13.740153][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.740158][ 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) 
[ 13.740163][ C1] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:616) 
[ 13.740166][ C1] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 13.740171][ 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) 
[ 13.740175][ C1] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 13.740179][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 13.740184][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 13.740188][ 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:2366) 
[ 13.740192][ C1] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 13.740197][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 13.740200][ C1] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 13.740205][ C1] ? kthread (kernel/kthread.c:464) 
[ 13.740209][ C1] ? ret_from_fork (arch/x86/kernel/process.c:153) 
[ 13.740213][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 13.740218][ C1] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2417) 
[ 13.740221][ C1] ? __pfx_migrate_enable (kernel/sched/core.c:2392) 
[ 13.740226][ C1] __put_net (net/core/net_namespace.c:732) 
[ 13.740230][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 13.740234][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 13.740237][ C1] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 13.740243][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 13.740247][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.740250][ C1] ? note_gp_changes (kernel/rcu/tree.c:1324 (discriminator 1)) 
[ 13.740252][ C1] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 13.740257][ C1] rcu_core (kernel/rcu/tree.c:2826) 
[ 13.740261][ C1] handle_softirqs (kernel/softirq.c:579) 
[ 13.740265][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 13.740269][ C1] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 13.740271][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 13.740275][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 13.740279][ C1] kthread (kernel/kthread.c:464) 
[ 13.740283][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.740286][ C1] ? ret_from_fork (arch/x86/kernel/process.c:152) 
[ 13.740288][ C1] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 13.740292][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 13.740294][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 13.740298][ C1] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 13.740301][ 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