rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P5904/1:b..l
rcu: 	(detected by 1, t=10502 jiffies, g=27837, q=15158 ncpus=2)
task:kworker/1:7     state:R  running task     stack:21216 pid:5904  tgid:5904  ppid:2      task_flags:0x4208060 flags:0x00080000
Workqueue: mm_percpu_wq lru_add_drain_per_cpu
Call Trace:
 <TASK>
 context_switch kernel/sched/core.c:5396 [inline]
 __schedule+0x16f9/0x5500 kernel/sched/core.c:7197
 preempt_schedule_irq+0x4d/0xa0 kernel/sched/core.c:7521
 irqentry_exit_to_kernel_mode include/linux/irq-entry-common.h:547 [inline]
 irqentry_exit+0x14f/0x760 kernel/entry/common.c:164
 asm_sysvec_apic_timer_interrupt+0x1a/0x20 arch/x86/include/asm/idtentry.h:674
RIP: 0010:lock_acquire+0x221/0x350 kernel/locking/lockdep.c:5874
Code: ff ff ff e8 f1 1d 88 09 f7 44 24 08 00 02 00 00 0f 84 3a ff ff ff 65 48 8b 05 cb a8 cf 10 48 3b 44 24 58 75 33 fb 48 83 c4 60 <5b> 41 5c 41 5d 41 5e 41 5f 5d c3 cc cc cc cc cc 48 8d 3d 18 98 ed
RSP: 0018:ffffc90005f9fa00 EFLAGS: 00000286
RAX: 0c432a67411ce200 RBX: 0000000000000000 RCX: 0000000000000046
RDX: 00000000b4363e28 RSI: ffffffff8d88874d RDI: ffffffff8ba85b60
RBP: ffffffff8b2ad9d0 R08: ffffffff8b2ad9d0 R09: ffffffff8dfc8240
R10: dffffc0000000000 R11: fffffbfff1f1597f R12: 0000000000000002
R13: ffffffff8dfc8240 R14: 0000000000000000 R15: 0000000000000246
 rcu_lock_acquire include/linux/rcupdate.h:300 [inline]
 rcu_read_lock include/linux/rcupdate.h:838 [inline]
 __rt_spin_lock kernel/locking/spinlock_rt.c:50 [inline]
 rt_spin_lock+0x1fc/0x400 kernel/locking/spinlock_rt.c:57
 spin_lock include/linux/spinlock_rt.h:45 [inline]
 mlock_drain_local+0x13e/0x4b0 mm/mlock.c:216
 process_one_work+0x98b/0x1630 kernel/workqueue.c:3306
 process_scheduled_works kernel/workqueue.c:3389 [inline]
 worker_thread+0xb49/0x1140 kernel/workqueue.c:3470
 kthread+0x388/0x470 kernel/kthread.c:436
 ret_from_fork+0x514/0xb70 arch/x86/kernel/process.c:158
 ret_from_fork_asm+0x1a/0x30 arch/x86/entry/entry_64.S:245
 </TASK>