rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
	(detected by 1, t=10502 jiffies, g=6981, q=52)
rcu: All QSes seen, last rcu_preempt kthread activity 10503 (4294954048-4294943545), jiffies_till_next_fqs=1, root ->qsmask 0x0
rsyslogd        R  running task    28512  8366      1 0x0000400a
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:memcg_kmem_uncharge include/linux/memcontrol.h:1402 [inline]
RIP: 0010:free_thread_stack+0x124/0x590 kernel/fork.c:284
Code: ff 48 c1 e8 06 48 83 e0 c0 48 bf 00 00 00 00 00 ea ff ff 48 01 c7 be 03 00 00 00 e8 06 a2 60 00 e9 5d 04 00 00 e8 5c 2d 2e 00 <48> 89 df 31 f6 e8 42 af 6e 00 43 80 3c 2e 00 74 08 4c 89 e7 e8 43
RSP: 0018:ffffc90001cb7a60 EFLAGS: 00000293 ORIG_RAX: ffffffffffffff13
RAX: ffffffff81486ea4 RBX: ffffea0001b06080 RCX: ffff8880903d8380
RDX: 0000000000000000 RSI: 00000000fffffffc RDI: ffffea0001b06080
RBP: ffffc90001cb7a98 R08: 000000000003a768 R09: ffffed10131c6ef7
R10: ffffed10131c6ef7 R11: 0000000000000000 R12: ffff88806c16f4a0
R13: dffffc0000000000 R14: 1ffff1100d82de94 R15: ffff888098e377a8
 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
 schedule+0x181/0x210 kernel/sched/core.c:4155
 do_syslog+0xdc7/0x1740 kernel/printk/printk.c:1525
 kmsg_read+0x94/0xd0 fs/proc/kmsg.c:40
 proc_reg_read+0x1e2/0x2d0 fs/proc/inode.c:223
 __vfs_read+0xb8/0x730 fs/read_write.c:425
 vfs_read+0x1dd/0x420 fs/read_write.c:461
 ksys_read+0x117/0x220 fs/read_write.c:587
 __do_sys_read fs/read_write.c:597 [inline]
 __se_sys_read fs/read_write.c:595 [inline]
 __x64_sys_read+0x7b/0x90 fs/read_write.c:595
 do_syscall_64+0xf7/0x1c0 arch/x86/entry/common.c:294
 entry_SYSCALL_64_after_hwframe+0x49/0xbe
RIP: 0033:0x7fdfd6db91fd
Code: d1 20 00 00 75 10 b8 00 00 00 00 0f 05 48 3d 01 f0 ff ff 73 31 c3 48 83 ec 08 e8 5e fa ff ff 48 89 04 24 b8 00 00 00 00 0f 05 <48> 8b 3c 24 48 89 c2 e8 a7 fa ff ff 48 89 d0 48 83 c4 08 48 3d 01
RSP: 002b:00007fdfd4358e30 EFLAGS: 00000293 ORIG_RAX: 0000000000000000
RAX: ffffffffffffffda RBX: 00000000018f4650 RCX: 00007fdfd6db91fd
RDX: 0000000000000fff RSI: 00007fdfd5b8d5a0 RDI: 0000000000000004
RBP: 0000000000000000 R08: 00000000018df260 R09: 0000000000000000
R10: 203a7463656a626f R11: 0000000000000293 R12: 000000000065e420
R13: 00007fdfd43599c0 R14: 00007fdfd73fe040 R15: 0000000000000003
rcu: rcu_preempt kthread starved for 10535 jiffies! g6981 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
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