======================================
| [   16.681404][    C3] 1 lock held by ksoftirqd/3/32:
| [ 16.681592][ C3] #0: ffffffff8a375140 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2562) 
| [   16.681924][    C3]
| [   16.681924][    C3] stack backtrace:
[   16.682159][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   16.682162][    C3] Call Trace:
[   16.682164][    C3]  <TASK>
[ 16.682167][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 16.682174][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4046) 
[ 16.682178][ C3] mark_lock_irq (kernel/locking/lockdep.c:4011 kernel/locking/lockdep.c:4057 kernel/locking/lockdep.c:4268) 
[ 16.682183][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 16.682188][ C3] ? save_trace (kernel/locking/lockdep.c:594) 
[ 16.682193][ C3] mark_lock (kernel/locking/lockdep.c:4754) 
[ 16.682197][ C3] mark_usage (kernel/locking/lockdep.c:4643) 
[ 16.682200][ C3] __lock_acquire (kernel/locking/lockdep.c:5189) 
[ 16.682205][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:472 kernel/locking/lockdep.c:5868) 
[ 16.682208][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 16.682211][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 16.682217][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5829) 
[ 16.682220][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 16.682224][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 16.682227][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 16.682230][ C3] simple_pin_fs (fs/libfs.c:1066) 
[ 16.682233][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 16.682236][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 16.682244][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 16.682247][ 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:2366) 
[ 16.682254][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 16.682256][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 16.682259][ C3] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 16.682267][ C3] ? kthread (kernel/kthread.c:464) 
[ 16.682271][ C3] ? ret_from_fork (arch/x86/kernel/process.c:153) 
[ 16.682274][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 16.682276][ C3] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2417) 
[ 16.682281][ C3] ? __pfx_migrate_enable (kernel/sched/core.c:2392) 
[ 16.682287][ C3] __put_net (net/core/net_namespace.c:732) 
[ 16.682290][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 16.682294][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 16.682296][ C3] rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 16.682301][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 16.682304][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 16.682307][ C3] ? note_gp_changes (kernel/rcu/tree.c:1324 (discriminator 1)) 
[ 16.682310][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 16.682318][ C3] rcu_core (kernel/rcu/tree.c:2826) 
[ 16.682323][ C3] handle_softirqs (kernel/softirq.c:580) 
[ 16.682327][ C3] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 16.682331][ C3] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 16.682334][ C3] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 16.682338][ C3] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 16.682342][ C3] kthread (kernel/kthread.c:464) 
[ 16.682345][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 16.682347][ C3] ? ret_from_fork (arch/x86/kernel/process.c:152) 
[ 16.682350][ C3] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 16.682353][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 16.682356][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 16.682359][ C3] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 16.682362][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 16.682365][ C3] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   16.693531][    C3] RCU nest depth: 0, expected: 0
| [   16.693703][    C3] INFO: lockdep is turned off.
| [   16.693882][    C3] Preemption disabled at:
| [ 16.693883][ C3] handle_softirqs (kernel/softirq.c:553) 
[   16.694239][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   16.694240][    C3] Call Trace:
[   16.694242][    C3]  <TASK>
[ 16.694243][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 16.694248][ C3] __might_resched (kernel/sched/core.c:8819) 
[ 16.694256][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 16.694260][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 16.694262][ C3] ? simple_recursive_removal (./include/linux/dcache.h:345 fs/libfs.c:610) 
[ 16.694267][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 16.694271][ 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) 
[ 16.694277][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:616) 
[ 16.694279][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 16.694283][ 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) 
[ 16.694288][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 16.694291][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 16.694296][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 16.694299][ 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:2366) 
[ 16.694303][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 16.694306][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 16.694309][ C3] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 16.694313][ C3] ? kthread (kernel/kthread.c:464) 
[ 16.694316][ C3] ? ret_from_fork (arch/x86/kernel/process.c:153) 
[ 16.694319][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 16.694322][ C3] ? migrate_enable (./arch/x86/include/asm/preempt.h:104 ./include/linux/preempt.h:481 ./include/linux/preempt.h:481 kernel/sched/core.c:2417) 
[ 16.694325][ C3] ? __pfx_migrate_enable (kernel/sched/core.c:2392) 
[ 16.694331][ C3] __put_net (net/core/net_namespace.c:732) 
[ 16.694333][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 16.694337][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 16.694339][ C3] rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 16.694344][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 16.694347][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 16.694350][ C3] ? note_gp_changes (kernel/rcu/tree.c:1324 (discriminator 1)) 
[ 16.694353][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 16.694358][ C3] rcu_core (kernel/rcu/tree.c:2826) 
[ 16.694362][ C3] handle_softirqs (kernel/softirq.c:580) 
[ 16.694367][ C3] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 16.694370][ C3] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 16.694373][ C3] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 16.694377][ C3] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 16.694381][ C3] kthread (kernel/kthread.c:464) 
[ 16.694384][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 16.694386][ C3] ? ret_from_fork (arch/x86/kernel/process.c:152) 
[ 16.694389][ C3] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 16.694392][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 16.694396][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 16.694399][ C3] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 16.694401][ 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