rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
rcu: 	Tasks blocked on level-0 rcu_node (CPUs 0-1): P7840
rcu: 	(detected by 0, t=10503 jiffies, g=119525, q=803)
kworker/0:3     R  running task    25784  7840      2 0x80000000
Workqueue: events_power_efficient gc_worker
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 preempt_schedule_irq+0xb0/0x140 kernel/sched/core.c:3744
 retint_kernel+0x1b/0x2d
RIP: 0010:write_comp_data+0x23/0x70 kernel/kcov.c:122
Code: 1f 84 00 00 00 00 00 49 89 f1 49 89 fa 65 48 8b 34 25 c0 df 01 00 65 8b 05 7a 59 9f 7e a9 00 01 1f 00 75 4f 8b 86 60 13 00 00 <83> f8 03 75 44 48 8b 86 68 13 00 00 8b b6 64 13 00 00 48 8b 38 48
RSP: 0018:ffff888096c37c50 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: 0000000000010000 RCX: ffffffff86a4c975
RDX: 0000000000010000 RSI: ffff88808f3961c0 RDI: 0000000000000004
RBP: 0000000000000000 R08: ffffffff8cd552b0 R09: 0000000000000414
R10: 0000000000000004 R11: 0000000000000000 R12: ffff8880a4d00080
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000414
 gc_worker+0x335/0xe90 net/netfilter/nf_conntrack_core.c:1215
 process_one_work+0x864/0x1570 kernel/workqueue.c:2153
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
kworker/0:3     R  running task    25784  7840      2 0x80000000
Workqueue: events_power_efficient gc_worker
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 preempt_schedule_irq+0xb0/0x140 kernel/sched/core.c:3744
 retint_kernel+0x1b/0x2d
RIP: 0010:write_comp_data+0x23/0x70 kernel/kcov.c:122
Code: 1f 84 00 00 00 00 00 49 89 f1 49 89 fa 65 48 8b 34 25 c0 df 01 00 65 8b 05 7a 59 9f 7e a9 00 01 1f 00 75 4f 8b 86 60 13 00 00 <83> f8 03 75 44 48 8b 86 68 13 00 00 8b b6 64 13 00 00 48 8b 38 48
RSP: 0018:ffff888096c37c50 EFLAGS: 00000246 ORIG_RAX: ffffffffffffff13
RAX: 0000000000000000 RBX: 0000000000010000 RCX: ffffffff86a4c975
RDX: 0000000000010000 RSI: ffff88808f3961c0 RDI: 0000000000000004
RBP: 0000000000000000 R08: ffffffff8cd552b0 R09: 0000000000000414
R10: 0000000000000004 R11: 0000000000000000 R12: ffff8880a4d00080
R13: 0000000000000000 R14: dffffc0000000000 R15: 0000000000000414
 gc_worker+0x335/0xe90 net/netfilter/nf_conntrack_core.c:1215
 process_one_work+0x864/0x1570 kernel/workqueue.c:2153
 worker_thread+0x64c/0x1130 kernel/workqueue.c:2296
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415
rcu: rcu_preempt kthread starved for 930 jiffies! g119525 f0x0 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
rcu: RCU grace-period kthread stack dump:
rcu_preempt     R  running task    29208    10      2 0x80000000
Call Trace:
 context_switch kernel/sched/core.c:2828 [inline]
 __schedule+0x887/0x2040 kernel/sched/core.c:3517
 schedule+0x8d/0x1b0 kernel/sched/core.c:3561
 schedule_timeout+0x4cf/0xfe0 kernel/time/timer.c:1818
 rcu_gp_kthread+0xdad/0x21c0 kernel/rcu/tree.c:2202
 kthread+0x33f/0x460 kernel/kthread.c:259
 ret_from_fork+0x24/0x30 arch/x86/entry/entry_64.S:415