rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=6317, q=167)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294954008-4294943505), jiffies_till_next_fqs=1, root ->qsmask 0x0
blkid           R  running task    28312  8175   8121 0x80004008
Call Trace:
 <IRQ>
 sched_show_task+0x40f/0x560 kernel/sched/core.c:5954
 print_other_cpu_stall kernel/rcu/tree_stall.h:410 [inline]
 check_cpu_stall kernel/rcu/tree_stall.h:538 [inline]
 rcu_pending kernel/rcu/tree.c:2827 [inline]
 rcu_sched_clock_irq+0x1861/0x1ad0 kernel/rcu/tree.c:2271
 update_process_times+0x12d/0x180 kernel/time/timer.c:1726
 tick_sched_handle kernel/time/tick-sched.c:167 [inline]
 tick_sched_timer+0x263/0x420 kernel/time/tick-sched.c:1310
 __run_hrtimer kernel/time/hrtimer.c:1514 [inline]
 __hrtimer_run_queues+0x403/0x840 kernel/time/hrtimer.c:1576
 hrtimer_interrupt+0x38c/0xda0 kernel/time/hrtimer.c:1638
 local_apic_timer_interrupt arch/x86/kernel/apic/apic.c:1110 [inline]
 smp_apic_timer_interrupt+0x109/0x280 arch/x86/kernel/apic/apic.c:1135
 apic_timer_interrupt+0xf/0x20 arch/x86/entry/entry_64.S:829
 </IRQ>
RIP: 0010:check_kcov_mode kernel/kcov.c:68 [inline]
RIP: 0010:__sanitizer_cov_trace_pc+0x14/0x50 kernel/kcov.c:102
Code: 00 00 00 48 8b 3d 74 25 cd 07 48 89 de e8 64 02 3b 00 5b 5d c3 cc 48 8b 04 24 65 48 8b 0c 25 c0 1d 02 00 65 8b 15 b8 81 8b 7e <f7> c2 00 01 1f 00 75 2c 8b 91 80 13 00 00 83 fa 02 75 21 48 8b 91
RSP: 0018:ffffc90002bd7870 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81487433 RBX: 0000000000000000 RCX: ffff88809debc0c0
RDX: 0000000000000001 RSI: 00000000fffffffc RDI: ffffea00023b3880
RBP: ffffc90002bd7898 R08: 000000000003a768 R09: ffffed101167469f
R10: ffffed101167469f R11: 0000000000000000 R12: dffffc0000000000
R13: dffffc0000000000 R14: 00000000fffffffc R15: ffff88808b3a34e8
 free_thread_stack+0x168/0x590 kernel/fork.c:280
 release_task_stack kernel/fork.c:440 [inline]
 put_task_stack+0xa3/0x130 kernel/fork.c:451
 finish_task_switch+0x3f1/0x550 kernel/sched/core.c:3256
 context_switch kernel/sched/core.c:3388 [inline]
 __schedule+0x9a8/0xcc0 kernel/sched/core.c:4081
 preempt_schedule_irq+0xc1/0x140 kernel/sched/core.c:4338
 retint_kernel+0x1b/0x2b
RIP: 0010:arch_local_irq_restore arch/x86/include/asm/paravirt.h:752 [inline]
RIP: 0010:kmem_cache_free+0xc8/0xf0 mm/slab.c:3695
Code: 58 07 00 74 42 4c 89 f7 57 9d 0f 1f 44 00 00 e8 0e 98 ca ff eb 19 e8 a7 95 ca ff 48 83 3d 07 f7 58 07 00 74 24 4c 89 f7 57 9d <0f> 1f 44 00 00 4c 89 e7 4c 89 fe e8 58 01 00 00 5b 41 5c 41 5e 41
RSP: 0018:ffffc90002bd7af0 EFLAGS: 00000286 ORIG_RAX: ffffffffffffff13
RAX: ffff88809debc954 RBX: ffff88821bc46700 RCX: ffff88809debc0c0
RDX: 0000000000000000 RSI: ffffffff81a70bdc RDI: 0000000000000286
RBP: ffffc90002bd7b10 R08: ffff88809debc918 R09: ffffc90002bd7918
R10: 0000000000000010 R11: 0000000000000000 R12: ffffffff81a70bdc
R13: ffff88809ff7c7b0 R14: 0000000000000286 R15: ffff8880a70e0380
 anon_vma_chain_free mm/rmap.c:135 [inline]
 unlink_anon_vmas+0x61c/0x690 mm/rmap.c:439
 free_pgtables+0x1ae/0x300 mm/memory.c:413
 exit_mmap+0x28a/0x530 mm/mmap.c:3141
 __mmput+0x120/0x3a0 kernel/fork.c:1082
 mmput+0x5d/0x70 kernel/fork.c:1103
 exit_mm+0x50a/0x590 kernel/exit.c:485
 do_exit+0x544/0x2020 kernel/exit.c:784
 do_group_exit+0x15c/0x2b0 kernel/exit.c:895
 __do_sys_exit_group+0x17/0x20 kernel/exit.c:906
 __se_sys_exit_group+0x14/0x20 kernel/exit.c:904
 __x64_sys_exit_group+0x3b/0x40 kernel/exit.c:904
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7f3302bc41e8
Code: Bad RIP value.
RSP: 002b:00007ffdf5aab6f8 EFLAGS: 00000246 ORIG_RAX: 00000000000000e7
RAX: ffffffffffffffda RBX: 0000000000000002 RCX: 00007f3302bc41e8
RDX: 0000000000000002 RSI: 000000000000003c RDI: 0000000000000002
RBP: 00007f3302e99840 R08: 00000000000000e7 R09: ffffffffffffffa8
R10: 00007f3302e9f740 R11: 0000000000000246 R12: 00007f3302e99840
R13: 0000000000000001 R14: 0000000000000000 R15: 0000000000000000
rcu: rcu_preempt kthread starved for 10543 jiffies! g6317 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=1
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29032    10      2 0x80004000
Call Trace:
 context_switch kernel/sched/core.c:3385 [inline]
 __schedule+0x9a0/0xcc0 kernel/sched/core.c:4081
 schedule+0x181/0x210 kernel/sched/core.c:4155
 schedule_timeout+0x14f/0x240 kernel/time/timer.c:1895
 rcu_gp_fqs_loop kernel/rcu/tree.c:1661 [inline]
 rcu_gp_kthread+0xed8/0x1770 kernel/rcu/tree.c:1821
 kthread+0x332/0x350 kernel/kthread.c:255
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:352