Testing all events: OK Running tests again, along with the function tracer Running tests on all trace events: Testing all events: hrtimer: interrupt took 10901376 ns BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 12s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: vmstat_shepherd workqueue events_power_efficient: flags=0x82 pwq 2: cpus=0 flags=0x4 nice=0 active=1/256 refcnt=3 pending: neigh_periodic_work BUG: workqueue lockup - pool cpus=0 flags=0x5 nice=0 stuck for 11s! Showing busy workqueues and worker pools: workqueue events_power_efficient: flags=0x82 pwq 2: cpus=0 flags=0x5 nice=0 active=3/256 refcnt=5 in-flight: 99:check_lifetime pending: neigh_periodic_work, do_cache_clean pool 2: cpus=0 flags=0x5 nice=0 hung=11s workers=2 manager: 61 BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 10s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: vmstat_shepherd workqueue events_power_efficient: flags=0x82 pwq 2: cpus=0 flags=0x4 nice=0 active=1/256 refcnt=3 in-flight: 107:check_lifetime pool 2: cpus=0 flags=0x4 nice=0 hung=8s workers=4 idle: 99 106 61 BUG: workqueue lockup - pool cpus=0 node=0 flags=0x0 nice=0 stuck for 20s! Showing busy workqueues and worker pools: workqueue events: flags=0x0 pwq 0: cpus=0 node=0 flags=0x0 nice=0 active=1/256 refcnt=2 pending: vmstat_shepherd workqueue events_power_efficient: flags=0x82 pwq 2: cpus=0 flags=0x4 nice=0 active=1/256 refcnt=3 in-flight: 107:check_lifetime pool 2: cpus=0 flags=0x4 nice=0 hung=2s workers=4 idle: 99 106 61 rcu: INFO: rcu_preempt detected stalls on CPUs/tasks: (detected by 0, t=3752 jiffies, g=2501, q=1) rcu: All QSes seen, last rcu_preempt kthread activity 3472 (4295298049-4295294577), jiffies_till_next_fqs=1, root ->qsmask 0x0 rcu: rcu_preempt kthread starved for 3472 jiffies! g2501 f0x2 RCU_GP_WAIT_FQS(5) ->state=0x402 ->cpu=0 rcu: Unless rcu_preempt kthread gets sufficient CPU time, OOM is now expected behavior. rcu: RCU grace-period kthread stack dump: task:rcu_preempt state:I stack: 0 pid: 10 ppid: 2 flags:0x0000042a Call trace: dump_backtrace+0x0/0x240 arch/arm64/kernel/stacktrace.c:100 show_stack+0x34/0x88 arch/arm64/kernel/stacktrace.c:196 sched_show_task kernel/sched/core.c:6444 [inline] sched_show_task+0x1fc/0x228 kernel/sched/core.c:6419 rcu_check_gp_kthread_starvation+0xc8/0xe4 kernel/rcu/tree_stall.h:465 print_other_cpu_stall kernel/rcu/tree_stall.h:532 [inline] check_cpu_stall kernel/rcu/tree_stall.h:652 [inline] rcu_pending kernel/rcu/tree.c:3752 [inline] rcu_sched_clock_irq+0xc2c/0xd40 kernel/rcu/tree.c:2581 update_process_times+0x6c/0xb8 kernel/time/timer.c:1709 tick_sched_handle.isra.0+0x58/0x88 kernel/time/tick-sched.c:176 tick_sched_timer+0x68/0xe0 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1519 [inline] __hrtimer_run_queues+0x288/0x730 kernel/time/hrtimer.c:1583 hrtimer_interrupt+0x114/0x288 kernel/time/hrtimer.c:1645 timer_handler drivers/clocksource/arm_arch_timer.c:647 [inline] arch_timer_handler_virt+0x50/0x70 drivers/clocksource/arm_arch_timer.c:658 handle_percpu_devid_irq+0x104/0x4c0 kernel/irq/chip.c:930 generic_handle_irq_desc include/linux/irqdesc.h:152 [inline] generic_handle_irq+0x54/0x78 kernel/irq/irqdesc.c:650 __handle_domain_irq+0xac/0x130 kernel/irq/irqdesc.c:687 handle_domain_irq include/linux/irqdesc.h:170 [inline] gic_handle_irq+0x70/0x108 drivers/irqchip/irq-gic.c:370 el1_irq+0xc0/0x180 arch/arm64/kernel/entry.S:651 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:124 [inline] rcu_irq_enter_irqson+0x40/0x78 kernel/rcu/tree.c:1078 trace_preempt_disable_rcuidle include/trace/events/preemptirq.h:51 [inline] trace_preempt_off+0x108/0x1f8 kernel/trace/trace_preemptirq.c:130 preempt_latency_start kernel/sched/core.c:4163 [inline] preempt_latency_start kernel/sched/core.c:4156 [inline] preempt_schedule_common+0x170/0x1a8 kernel/sched/core.c:4679 preempt_schedule+0x38/0x40 kernel/sched/core.c:4705 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0x90/0xa0 kernel/locking/spinlock.c:191 prepare_to_swait_event+0x84/0xe8 kernel/sched/swait.c:120 rcu_gp_fqs_loop kernel/rcu/tree.c:1942 [inline] rcu_gp_kthread+0x630/0x1bd8 kernel/rcu/tree.c:2115 kthread+0x13c/0x188 kernel/kthread.c:292 ret_from_fork+0x10/0x34 arch/arm64/kernel/entry.S:961 ================================ WARNING: inconsistent lock state 5.10.0-rc3-next-20201110-00003-g891a69a3957e #1 Not tainted -------------------------------- inconsistent {IN-HARDIRQ-W} -> {HARDIRQ-ON-W} usage. rcu_preempt/10 [HC0[0]:SC0[0]:HE0:SE1] takes: ffffb80c721e4458 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:493 [inline] ffffb80c721e4458 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:652 [inline] ffffb80c721e4458 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3752 [inline] ffffb80c721e4458 (rcu_node_0){?.-.}-{2:2}, at: rcu_sched_clock_irq+0x428/0xd40 kernel/rcu/tree.c:2581 {IN-HARDIRQ-W} state was registered at: mark_lock kernel/locking/lockdep.c:4374 [inline] mark_usage kernel/locking/lockdep.c:4302 [inline] __lock_acquire+0xaa8/0x1a50 kernel/locking/lockdep.c:4785 lock_acquire kernel/locking/lockdep.c:5436 [inline] lock_acquire+0x268/0x508 kernel/locking/lockdep.c:5401 __raw_spin_lock_irqsave include/linux/spinlock_api_smp.h:110 [inline] _raw_spin_lock_irqsave+0x78/0x14c kernel/locking/spinlock.c:159 print_other_cpu_stall kernel/rcu/tree_stall.h:493 [inline] check_cpu_stall kernel/rcu/tree_stall.h:652 [inline] rcu_pending kernel/rcu/tree.c:3752 [inline] rcu_sched_clock_irq+0x428/0xd40 kernel/rcu/tree.c:2581 update_process_times+0x6c/0xb8 kernel/time/timer.c:1709 tick_sched_handle.isra.0+0x58/0x88 kernel/time/tick-sched.c:176 tick_sched_timer+0x68/0xe0 kernel/time/tick-sched.c:1328 __run_hrtimer kernel/time/hrtimer.c:1519 [inline] __hrtimer_run_queues+0x288/0x730 kernel/time/hrtimer.c:1583 hrtimer_interrupt+0x114/0x288 kernel/time/hrtimer.c:1645 timer_handler drivers/clocksource/arm_arch_timer.c:647 [inline] arch_timer_handler_virt+0x50/0x70 drivers/clocksource/arm_arch_timer.c:658 handle_percpu_devid_irq+0x104/0x4c0 kernel/irq/chip.c:930 generic_handle_irq_desc include/linux/irqdesc.h:152 [inline] generic_handle_irq+0x54/0x78 kernel/irq/irqdesc.c:650 __handle_domain_irq+0xac/0x130 kernel/irq/irqdesc.c:687 handle_domain_irq include/linux/irqdesc.h:170 [inline] gic_handle_irq+0x70/0x108 drivers/irqchip/irq-gic.c:370 el1_irq+0xc0/0x180 arch/arm64/kernel/entry.S:651 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:124 [inline] rcu_irq_enter_irqson+0x40/0x78 kernel/rcu/tree.c:1078 trace_preempt_disable_rcuidle include/trace/events/preemptirq.h:51 [inline] trace_preempt_off+0x108/0x1f8 kernel/trace/trace_preemptirq.c:130 preempt_latency_start kernel/sched/core.c:4163 [inline] preempt_latency_start kernel/sched/core.c:4156 [inline] preempt_schedule_common+0x170/0x1a8 kernel/sched/core.c:4679 preempt_schedule+0x38/0x40 kernel/sched/core.c:4705 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0x90/0xa0 kernel/locking/spinlock.c:191 prepare_to_swait_event+0x84/0xe8 kernel/sched/swait.c:120 rcu_gp_fqs_loop kernel/rcu/tree.c:1942 [inline] rcu_gp_kthread+0x630/0x1bd8 kernel/rcu/tree.c:2115 kthread+0x13c/0x188 kernel/kthread.c:292 ret_from_fork+0x10/0x34 arch/arm64/kernel/entry.S:961 irq event stamp: 43978 hardirqs last enabled at (43977): [] rcu_irq_enter_irqson+0x64/0x78 kernel/rcu/tree.c:1078 hardirqs last disabled at (43978): [] el1_irq+0x80/0x180 arch/arm64/kernel/entry.S:648 softirqs last enabled at (43682): [] __do_softirq+0x630/0x6b4 kernel/softirq.c:325 softirqs last disabled at (43673): [] do_softirq_own_stack include/linux/interrupt.h:568 [inline] softirqs last disabled at (43673): [] invoke_softirq kernel/softirq.c:393 [inline] softirqs last disabled at (43673): [] __irq_exit_rcu kernel/softirq.c:423 [inline] softirqs last disabled at (43673): [] irq_exit+0x1cc/0x1e0 kernel/softirq.c:447 other info that might help us debug this: Possible unsafe locking scenario: CPU0 ---- lock(rcu_node_0); lock(rcu_node_0); *** DEADLOCK *** 1 lock held by rcu_preempt/10: #0: ffffb80c721e4458 (rcu_node_0){?.-.}-{2:2}, at: print_other_cpu_stall kernel/rcu/tree_stall.h:493 [inline] #0: ffffb80c721e4458 (rcu_node_0){?.-.}-{2:2}, at: check_cpu_stall kernel/rcu/tree_stall.h:652 [inline] #0: ffffb80c721e4458 (rcu_node_0){?.-.}-{2:2}, at: rcu_pending kernel/rcu/tree.c:3752 [inline] #0: ffffb80c721e4458 (rcu_node_0){?.-.}-{2:2}, at: rcu_sched_clock_irq+0x428/0xd40 kernel/rcu/tree.c:2581 stack backtrace: CPU: 0 PID: 10 Comm: rcu_preempt Not tainted 5.10.0-rc3-next-20201110-00003-g891a69a3957e #1 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x240 arch/arm64/kernel/stacktrace.c:100 show_stack+0x34/0x88 arch/arm64/kernel/stacktrace.c:196 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x140/0x1bc lib/dump_stack.c:118 print_usage_bug kernel/locking/lockdep.c:3739 [inline] print_usage_bug+0x2a0/0x2f0 kernel/locking/lockdep.c:3706 valid_state kernel/locking/lockdep.c:3750 [inline] mark_lock_irq kernel/locking/lockdep.c:3953 [inline] mark_lock.part.0+0x438/0x4e8 kernel/locking/lockdep.c:4410 mark_lock kernel/locking/lockdep.c:4008 [inline] mark_held_locks+0x54/0x90 kernel/locking/lockdep.c:4011 __trace_hardirqs_on_caller kernel/locking/lockdep.c:4029 [inline] lockdep_hardirqs_on_prepare+0xe0/0x290 kernel/locking/lockdep.c:4097 trace_hardirqs_on+0x90/0x370 kernel/trace/trace_preemptirq.c:49 el1_irq+0xdc/0x180 arch/arm64/kernel/entry.S:685 arch_local_irq_restore arch/arm64/include/asm/irqflags.h:124 [inline] rcu_irq_enter_irqson+0x40/0x78 kernel/rcu/tree.c:1078 trace_preempt_disable_rcuidle include/trace/events/preemptirq.h:51 [inline] trace_preempt_off+0x108/0x1f8 kernel/trace/trace_preemptirq.c:130 preempt_latency_start kernel/sched/core.c:4163 [inline] preempt_latency_start kernel/sched/core.c:4156 [inline] preempt_schedule_common+0x170/0x1a8 kernel/sched/core.c:4679 preempt_schedule+0x38/0x40 kernel/sched/core.c:4705 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0x90/0xa0 kernel/locking/spinlock.c:191 prepare_to_swait_event+0x84/0xe8 kernel/sched/swait.c:120 rcu_gp_fqs_loop kernel/rcu/tree.c:1942 [inline] rcu_gp_kthread+0x630/0x1bd8 kernel/rcu/tree.c:2115 kthread+0x13c/0x188 kernel/kthread.c:292 ret_from_fork+0x10/0x34 arch/arm64/kernel/entry.S:961 BUG: scheduling while atomic: rcu_preempt/10/0x00000002 INFO: lockdep is turned off. Modules linked in: Preemption disabled at: [] preempt_schedule+0x38/0x40 kernel/sched/core.c:4705 CPU: 0 PID: 10 Comm: rcu_preempt Not tainted 5.10.0-rc3-next-20201110-00003-g891a69a3957e #1 Hardware name: linux,dummy-virt (DT) Call trace: dump_backtrace+0x0/0x240 arch/arm64/kernel/stacktrace.c:100 show_stack+0x34/0x88 arch/arm64/kernel/stacktrace.c:196 __dump_stack lib/dump_stack.c:77 [inline] dump_stack+0x140/0x1bc lib/dump_stack.c:118 __schedule_bug+0xcc/0xe0 kernel/sched/core.c:4261 schedule_debug kernel/sched/core.c:4288 [inline] __schedule+0x888/0x970 kernel/sched/core.c:4416 preempt_schedule_common+0x4c/0x1a8 kernel/sched/core.c:4680 preempt_schedule+0x38/0x40 kernel/sched/core.c:4705 __raw_spin_unlock_irqrestore include/linux/spinlock_api_smp.h:161 [inline] _raw_spin_unlock_irqrestore+0x90/0xa0 kernel/locking/spinlock.c:191 prepare_to_swait_event+0x84/0xe8 kernel/sched/swait.c:120 rcu_gp_fqs_loop kernel/rcu/tree.c:1942 [inline] rcu_gp_kthread+0x630/0x1bd8 kernel/rcu/tree.c:2115 kthread+0x13c/0x188 kernel/kthread.c:292 ret_from_fork+0x10/0x34 arch/arm64/kernel/entry.S:961