======================================
| [   12.570136][    C3] 1 lock held by ksoftirqd/3/32:
| [ 12.570309][ C3] #0: ffffffffa83774c0 (rcu_callback){....}-{0:0}, at: rcu_do_batch (./include/linux/rcupdate.h:331 kernel/rcu/tree.c:2570) 
| [   12.570616][    C3]
| [   12.570616][    C3] stack backtrace:
[   12.570832][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.570834][    C3] Call Trace:
[   12.570836][    C3]  <TASK>
[ 12.570839][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.570845][ C3] print_usage_bug.part.0 (kernel/locking/lockdep.c:4048) 
[ 12.570849][ C3] mark_lock_irq (kernel/locking/lockdep.c:4013 kernel/locking/lockdep.c:4059 kernel/locking/lockdep.c:4270) 
[ 12.570854][ C3] ? __pfx_unwind_next_frame (arch/x86/kernel/unwind_orc.c:469) 
[ 12.570859][ C3] ? save_trace (kernel/locking/lockdep.c:595) 
[ 12.570863][ C3] mark_lock (kernel/locking/lockdep.c:4756) 
[ 12.570867][ C3] mark_usage (kernel/locking/lockdep.c:4645) 
[ 12.570870][ C3] __lock_acquire (kernel/locking/lockdep.c:5194) 
[ 12.570874][ C3] ? __lock_acquire (kernel/locking/lockdep.c:5240) 
[ 12.570878][ C3] lock_acquire.part.0 (kernel/locking/lockdep.c:473 kernel/locking/lockdep.c:5873) 
[ 12.570881][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.570885][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.570889][ C3] ? lock_acquire (./include/trace/events/lock.h:24 kernel/locking/lockdep.c:5834) 
[ 12.570892][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.570896][ C3] _raw_spin_lock (./include/linux/spinlock_api_smp.h:134 kernel/locking/spinlock.c:154) 
[ 12.570899][ C3] ? simple_pin_fs (fs/libfs.c:1067) 
[ 12.570901][ C3] simple_pin_fs (fs/libfs.c:1067) 
[ 12.570905][ C3] debugfs_remove (fs/debugfs/inode.c:805 fs/debugfs/inode.c:799) 
[ 12.570908][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:411 lib/ref_tracker.c:195) 
[ 12.570913][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 12.570915][ 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) 
[ 12.570921][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.570924][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 12.570927][ C3] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.570930][ C3] ? kthread (kernel/kthread.c:464) 
[ 12.570933][ C3] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.570937][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.570939][ 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) 
[ 12.570943][ C3] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 12.570949][ C3] __put_net (net/core/net_namespace.c:732) 
[ 12.570953][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.570957][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.570960][ C3] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.570963][ C3] ? __schedule (kernel/sched/core.c:6658) 
[ 12.570968][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.570972][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.570975][ C3] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 12.570978][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.570984][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.570989][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 12.570993][ C3] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 12.570997][ C3] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 12.571000][ C3] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.571003][ C3] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 12.571006][ C3] kthread (kernel/kthread.c:464) 
[ 12.571009][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.571011][ C3] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 12.571014][ C3] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.571018][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.571021][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.571025][ C3] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.571028][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.571031][ C3] ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
| [   12.581710][    C3] RCU nest depth: 0, expected: 0
| [   12.581869][    C3] INFO: lockdep is turned off.
| [   12.582024][    C3] Preemption disabled at:
| [ 12.582026][ C3] handle_softirqs (kernel/softirq.c:553) 
[   12.582361][    C3] Hardware name: Bochs Bochs, BIOS Bochs 01/01/2011
[   12.582363][    C3] Call Trace:
[   12.582365][    C3]  <TASK>
[ 12.582367][ C3] dump_stack_lvl (lib/dump_stack.c:123) 
[ 12.582374][ C3] __might_resched (kernel/sched/core.c:8796) 
[ 12.582381][ C3] down_write (./include/linux/kernel.h:73 kernel/locking/rwsem.c:1576) 
[ 12.582385][ C3] ? __pfx_down_write (kernel/locking/rwsem.c:1575) 
[ 12.582388][ C3] ? simple_recursive_removal (fs/libfs.c:614) 
[ 12.582393][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.582399][ 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) 
[ 12.582403][ C3] simple_recursive_removal (./include/linux/dcache.h:409 ./include/linux/dcache.h:424 ./include/linux/dcache.h:434 fs/libfs.c:617) 
[ 12.582406][ 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) 
[ 12.582408][ C3] ? __pfx_remove_one (fs/debugfs/inode.c:780) 
[ 12.582414][ C3] debugfs_remove (fs/debugfs/inode.c:806 fs/debugfs/inode.c:799) 
[ 12.582418][ C3] ref_tracker_dir_exit (lib/ref_tracker.c:411 lib/ref_tracker.c:195) 
[ 12.582422][ C3] ? __pfx_ref_tracker_free (lib/ref_tracker.c:253) 
[ 12.582425][ 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) 
[ 12.582430][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.582434][ C3] ? __pfx_ref_tracker_dir_exit (lib/ref_tracker.c:189) 
[ 12.582437][ C3] ? smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.582440][ C3] ? kthread (kernel/kthread.c:464) 
[ 12.582443][ C3] ? ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.582447][ C3] ? ret_from_fork_asm (arch/x86/entry/entry_64.S:258) 
[ 12.582451][ 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) 
[ 12.582455][ C3] ? __pfx_migrate_enable (kernel/sched/core.c:2402) 
[ 12.582461][ C3] __put_net (net/core/net_namespace.c:732) 
[ 12.582465][ C3] __sk_destruct (./include/net/net_namespace.h:288 ./include/net/net_namespace.h:390 net/core/sock.c:2376) 
[ 12.582469][ C3] ? rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.582472][ C3] rcu_do_batch (kernel/rcu/tree.c:2576) 
[ 12.582475][ C3] ? __schedule (kernel/sched/core.c:6658) 
[ 12.582481][ C3] ? __pfx_rcu_do_batch (kernel/rcu/tree.c:2500) 
[ 12.582484][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.582487][ C3] ? note_gp_changes (kernel/rcu/tree.c:1326 (discriminator 1)) 
[ 12.582490][ C3] ? lockdep_hardirqs_on (kernel/locking/lockdep.c:4475) 
[ 12.582496][ C3] rcu_core (kernel/rcu/tree.c:2834) 
[ 12.582500][ C3] handle_softirqs (kernel/softirq.c:579) 
[ 12.582505][ C3] ? __pfx_run_ksoftirqd (kernel/softirq.c:961) 
[ 12.582509][ C3] run_ksoftirqd (kernel/softirq.c:436 kernel/softirq.c:969 kernel/softirq.c:960) 
[ 12.582512][ C3] smpboot_thread_fn (kernel/smpboot.c:164 (discriminator 3)) 
[ 12.582515][ C3] ? __pfx_smpboot_thread_fn (kernel/smpboot.c:107) 
[ 12.582518][ C3] kthread (kernel/kthread.c:464) 
[ 12.582521][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.582523][ C3] ? ret_from_fork (arch/x86/kernel/process.c:147) 
[ 12.582526][ C3] ? __lock_release (kernel/locking/lockdep.c:5539) 
[ 12.582531][ C3] ? rcu_is_watching (./include/linux/context_tracking.h:128 kernel/rcu/tree.c:745) 
[ 12.582535][ C3] ? __pfx_kthread (kernel/kthread.c:413) 
[ 12.582538][ C3] ret_from_fork (arch/x86/kernel/process.c:148) 
[ 12.582541][ 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