======================================
| [   14.734174][    C1] 1 lock held by ksoftirqd/1/22:
| [ 14.734409][ C1] #0: ffffffff8c7749c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2562) 
| [   14.734841][    C1]
| [   14.734841][    C1] stack backtrace:
[   14.735147][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   14.735150][    C1] Call Trace:
[   14.735153][    C1]  <TASK>
[ 14.735158][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 14.735167][ C1] print_usage_bug.part.0 (kernel/locking/lockdep.c:4046) 
[ 14.735175][ C1] mark_lock_irq (kernel/locking/lockdep.c:4011 kernel/locking/lockdep.c:4057 kernel/locking/lockdep.c:4268) 
[ 14.735180][ C1] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 14.735187][ C1] ? save_trace (kernel/locking/lockdep.c:594) 
[ 14.735195][ C1] mark_lock (kernel/locking/lockdep.c:4754) 
[ 14.735199][ C1] mark_usage (kernel/locking/lockdep.c:4643) 
[ 14.735203][ C1] __lock_acquire (kernel/locking/lockdep.c:5189) 
[ 14.735209][ C1] lock_acquire.part.0 (kernel/locking/lockdep.c:472 kernel/locking/lockdep.c:5868) 
[ 14.735213][ C1] ? simple_pin_fs (fs/libfs.c:1066) 
[ 14.735219][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 14.735223][ C1] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5829) 
[ 14.735226][ C1] ? simple_pin_fs (fs/libfs.c:1066) 
[ 14.735231][ C1] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 14.735235][ C1] ? simple_pin_fs (fs/libfs.c:1066) 
[ 14.735239][ C1] simple_pin_fs (fs/libfs.c:1066) 
[ 14.735243][ C1] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 14.735249][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 14.735257][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 14.735261][ 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) 
[ 14.735269][ C1] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 14.735273][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 14.735277][ C1] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 14.735284][ C1] ? kthread (kernel/kthread.c:464) 
[ 14.735290][ C1] ? ret_from_fork (arch/x86/kernel/process.c:153) 
[ 14.735295][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 14.735301][ 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) 
[ 14.735305][ C1] ? __pfx_migrate_enable (kernel/sched/core.c:2392) 
[ 14.735313][ C1] __put_net (net/core/net_namespace.c:732) 
[ 14.735318][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 14.735322][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 14.735327][ C1] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 14.735334][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 14.735339][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 14.735343][ C1] ? note_gp_changes (kernel/rcu/tree.c:1324 (discriminator 1)) 
[ 14.735346][ C1] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 14.735354][ C1] rcu_core (kernel/rcu/tree.c:2826) 
[ 14.735359][ C1] handle_softirqs (kernel/softirq.c:579) 
[ 14.735365][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 14.735369][ C1] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 14.735373][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 14.735377][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 14.735383][ C1] kthread (kernel/kthread.c:464) 
[ 14.735387][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 14.735391][ C1] ? ret_from_fork (arch/x86/kernel/process.c:152) 
[ 14.735394][ C1] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 14.735398][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 14.735401][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 14.735407][ C1] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 14.735411][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 14.735415][ C1] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   14.747356][    C1] RCU nest depth: 0, expected: 0
| [   14.747552][    C1] INFO: lockdep is turned off.
| [   14.747728][    C1] Preemption disabled at:
| [ 14.747730][ C1] handle_softirqs (kernel/softirq.c:553) 
[   14.748192][    C1] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   14.748194][    C1] Call Trace:
[   14.748197][    C1]  <TASK>
[ 14.748200][ C1] dump_stack_lvl (lib/dump_stack.c:123) 
[ 14.748209][ C1] __might_resched (kernel/sched/core.c:8819) 
[ 14.748217][ C1] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 14.748222][ C1] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 14.748225][ C1] ? simple_recursive_removal (./include/linux/dcache.h:345 fs/libfs.c:610) 
[ 14.748231][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 14.748237][ 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) 
[ 14.748243][ C1] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:616) 
[ 14.748246][ C1] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 14.748253][ 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) 
[ 14.748258][ C1] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 14.748261][ C1] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 14.748268][ C1] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 14.748272][ 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) 
[ 14.748278][ C1] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 14.748284][ C1] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 14.748287][ C1] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 14.748294][ C1] ? kthread (kernel/kthread.c:464) 
[ 14.748299][ C1] ? ret_from_fork (arch/x86/kernel/process.c:153) 
[ 14.748304][ C1] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 14.748310][ 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) 
[ 14.748314][ C1] ? __pfx_migrate_enable (kernel/sched/core.c:2392) 
[ 14.748320][ C1] __put_net (net/core/net_namespace.c:732) 
[ 14.748325][ C1] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 14.748329][ C1] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 14.748332][ C1] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 14.748338][ C1] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 14.748343][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 14.748345][ C1] ? note_gp_changes (kernel/rcu/tree.c:1324 (discriminator 1)) 
[ 14.748348][ C1] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 14.748354][ C1] rcu_core (kernel/rcu/tree.c:2826) 
[ 14.748358][ C1] handle_softirqs (kernel/softirq.c:579) 
[ 14.748363][ C1] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 14.748366][ C1] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 14.748369][ C1] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 14.748373][ C1] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 14.748377][ C1] kthread (kernel/kthread.c:464) 
[ 14.748381][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 14.748384][ C1] ? ret_from_fork (arch/x86/kernel/process.c:152) 
[ 14.748387][ C1] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 14.748390][ C1] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 14.748393][ C1] ? __pfx_kthread (kernel/kthread.c:413) 
[ 14.748397][ C1] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 14.748400][ 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