======================================
| [   15.443411][    C3] 1 lock held by ksoftirqd/3/32:
| [ 15.443633][ C3] #0: ffffffff8af749c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2562) 
| [   15.443983][    C3]
| [   15.443983][    C3] stack backtrace:
[   15.444278][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   15.444280][    C3] Call Trace:
[   15.444282][    C3]  <TASK>
[ 15.444285][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 15.444292][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4046) 
[ 15.444298][ C3] mark_lock_irq (kernel/locking/lockdep.c:4011 kernel/locking/lockdep.c:4057 kernel/locking/lockdep.c:4268) 
[ 15.444302][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 15.444307][ C3] ? save_trace (kernel/locking/lockdep.c:594) 
[ 15.444313][ C3] mark_lock (kernel/locking/lockdep.c:4754) 
[ 15.444317][ C3] mark_usage (kernel/locking/lockdep.c:4643) 
[ 15.444319][ C3] __lock_acquire (kernel/locking/lockdep.c:5189) 
[ 15.444324][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:472 kernel/locking/lockdep.c:5868) 
[ 15.444327][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 15.444332][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 15.444336][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5829) 
[ 15.444338][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 15.444342][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 15.444345][ C3] ? simple_pin_fs (fs/libfs.c:1066) 
[ 15.444348][ C3] simple_pin_fs (fs/libfs.c:1066) 
[ 15.444351][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 15.444355][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 15.444361][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 15.444364][ 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) 
[ 15.444370][ C3] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 15.444374][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 15.444377][ C3] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 15.444382][ C3] ? kthread (kernel/kthread.c:464) 
[ 15.444386][ C3] ? ret_from_fork (arch/x86/kernel/process.c:153) 
[ 15.444390][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 15.444394][ 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) 
[ 15.444398][ C3] ? __pfx_migrate_enable (kernel/sched/core.c:2392) 
[ 15.444403][ C3] __put_net (net/core/net_namespace.c:732) 
[ 15.444408][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 15.444414][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 15.444419][ C3] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 15.444428][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 15.444435][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 15.444440][ C3] ? note_gp_changes (kernel/rcu/tree.c:1324 (discriminator 1)) 
[ 15.444444][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 15.444453][ C3] rcu_core (kernel/rcu/tree.c:2826) 
[ 15.444459][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 15.444466][ C3] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 15.444473][ C3] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 15.444478][ C3] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 15.444484][ C3] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 15.444491][ C3] kthread (kernel/kthread.c:464) 
[ 15.444496][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 15.444499][ C3] ? ret_from_fork (arch/x86/kernel/process.c:152) 
[ 15.444502][ C3] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 15.444505][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 15.444508][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 15.444512][ C3] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 15.444514][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 15.444518][ C3] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   15.455970][    C3] RCU nest depth: 0, expected: 0
| [   15.456167][    C3] INFO: lockdep is turned off.
| [   15.456341][    C3] Preemption disabled at:
| [ 15.456351][ C3] handle_softirqs (kernel/softirq.c:553) 
[   15.456724][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   15.456727][    C3] Call Trace:
[   15.456728][    C3]  <TASK>
[ 15.456731][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 15.456738][ C3] __might_resched (kernel/sched/core.c:8819) 
[ 15.456744][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 15.456747][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 15.456750][ C3] ? simple_recursive_removal (./include/linux/dcache.h:345 fs/libfs.c:610) 
[ 15.456755][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 15.456759][ 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) 
[ 15.456764][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:616) 
[ 15.456768][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 15.456772][ 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) 
[ 15.456777][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 15.456780][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:423 lib/ref_tracker.c:195) 
[ 15.456786][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 15.456790][ 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) 
[ 15.456795][ C3] ? rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 15.456799][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 15.456803][ C3] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 15.456807][ C3] ? kthread (kernel/kthread.c:464) 
[ 15.456812][ C3] ? ret_from_fork (arch/x86/kernel/process.c:153) 
[ 15.456816][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 15.456820][ 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) 
[ 15.456823][ C3] ? __pfx_migrate_enable (kernel/sched/core.c:2392) 
[ 15.456828][ C3] __put_net (net/core/net_namespace.c:732) 
[ 15.456832][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2366) 
[ 15.456837][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2568) 
[ 15.456840][ C3] rcu_do_batch (./include/linux/rcupdate.h:341 kernel/rcu/tree.c:2570) 
[ 15.456845][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2492) 
[ 15.456850][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 15.456852][ C3] ? note_gp_changes (kernel/rcu/tree.c:1324 (discriminator 1)) 
[ 15.456855][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4473) 
[ 15.456860][ C3] rcu_core (kernel/rcu/tree.c:2826) 
[ 15.456864][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 15.456868][ C3] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 15.456872][ C3] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 15.456874][ C3] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 15.456878][ C3] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 15.456882][ C3] kthread (kernel/kthread.c:464) 
[ 15.456885][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 15.456889][ C3] ? ret_from_fork (arch/x86/kernel/process.c:152) 
[ 15.456891][ C3] ? __lock_release (kernel/locking/lockdep.c:5534) 
[ 15.456894][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:736) 
[ 15.456897][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 15.456901][ C3] ret_from_fork (arch/x86/kernel/process.c:153) 
[ 15.456904][ 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