Hi Tony, all,
since kernel 5.18.x (5.17.x doesn't show this behavior), the system
stalls as soon as I invoke the following commands (initializing
USB-to-CAN converter):
slcand -o -s8 -t hw -S 3000000 /dev/ttyUSB0
ip link set slcan0 up
Have you already seen such an issue? Should I try to bisect this?
[ 88.408578] rcu: INFO: rcu_sched detected stalls on CPUs/tasks:
[ 88.415777] (detected by 0, t=2602 jiffies, g=2529, q=17)
[ 88.422026] rcu: All QSes seen, last rcu_sched kthread activity
2602 (-21160--23762), jiffies_till_next_fqs=1, root ->qsmask 0x0
[ 88.434445] rcu: rcu_sched kthread starved for 2602 jiffies! g2529
f0x2 RCU_GP_WAIT_FQS(5) ->state=0x0 ->cpu=0
[ 88.445274] rcu: Unless rcu_sched kthread gets sufficient CPU
time, OOM is now expected behavior.
[ 88.454859] rcu: RCU grace-period kthread stack dump:
[ 88.460446] task:rcu_sched state:R running task stack:
0 pid: 11 ppid: 2 flags:0x00000000
[ 88.471840] __schedule from schedule+0x58/0xcc
[ 88.477680] schedule from schedule_timeout+0x78/0xf8
[ 88.483754] schedule_timeout from rcu_gp_fqs_loop+0x108/0x3cc
[ 88.490629] rcu_gp_fqs_loop from rcu_gp_kthread+0xa8/0x134
[ 88.497187] rcu_gp_kthread from kthread+0xe4/0x104
[ 88.503061] kthread from ret_from_fork+0x14/0x28
[ 88.508627] Exception stack(0xd0041fb0 to 0xd0041ff8)
[ 88.514443] 1fa0: 00000000
00000000 00000000 00000000
[ 88.523433] 1fc0: 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000
[ 88.532374] 1fe0: 00000000 00000000 00000000 00000000 00000013 00000000
[ 88.539639] rcu: Stack dump where RCU GP kthread last ran:
[ 88.545694] NMI backtrace for cpu 0
[ 88.549779] CPU: 0 PID: 58 Comm: kworker/0:8 Not tainted 5.18.0-rc5 #1
[ 88.557103] Hardware name: Generic AM33XX (Flattened Device Tree)
[ 88.563822] Workqueue: events dbs_work_handler
[ 88.569398] unwind_backtrace from show_stack+0x10/0x14
[ 88.575662] show_stack from dump_stack_lvl+0x58/0x70
[ 88.581627] dump_stack_lvl from nmi_cpu_backtrace+0xe0/0x128
[ 88.588345] nmi_cpu_backtrace from nmi_trigger_cpumask_backtrace+0xec/0x184
[ 88.596339] nmi_trigger_cpumask_backtrace from
trigger_single_cpu_backtrace+0x20/0x2c
[ 88.605221] trigger_single_cpu_backtrace from
rcu_check_gp_kthread_starvation+0xf4/0x148
[ 88.614328] rcu_check_gp_kthread_starvation from
rcu_sched_clock_irq+0xdf0/0xf7c
[ 88.622778] rcu_sched_clock_irq from update_process_times+0x88/0xc0
[ 88.630182] update_process_times from tick_sched_handle+0x48/0x54
[ 88.637293] tick_sched_handle from tick_sched_timer+0x48/0xac
[ 88.643993] tick_sched_timer from __hrtimer_run_queues+0x244/0x4d8
[ 88.651212] __hrtimer_run_queues from hrtimer_interrupt+0x128/0x2c8
[ 88.658582] hrtimer_interrupt from dmtimer_clockevent_interrupt+0x24/0x2c
[ 88.666506] dmtimer_clockevent_interrupt from
__handle_irq_event_percpu+0x98/0x334
[ 88.675241] __handle_irq_event_percpu from handle_irq_event+0x38/0xc0
[ 88.682749] handle_irq_event from handle_level_irq+0xb4/0x1a8
[ 88.689639] handle_level_irq from handle_irq_desc+0x1c/0x2c
[ 88.696253] handle_irq_desc from generic_handle_arch_irq+0x2c/0x64
[ 88.703524] generic_handle_arch_irq from __irq_svc+0x90/0xbc
[ 88.710195] Exception stack(0xd0001f58 to 0xd0001fa0)
[ 88.715947] 1f40:
c01015c8 00000000
[ 88.724939] 1f60: 0eae9000 00000000 fffffffe 60000013 ffffffff
d0385d74 00000000 c2702a80
[ 88.733926] 1f80: 00000002 c2702a80 00000000 d0001fa8 c01015c8
c01015d0 60000113 ffffffff
[ 88.742765] __irq_svc from __do_softirq+0xa0/0x604
[ 88.748533] __do_softirq from __irq_exit_rcu+0x138/0x178
[ 88.754961] __irq_exit_rcu from irq_exit+0x8/0x28
[ 88.760758] irq_exit from call_with_stack+0x18/0x20
[ 88.766687] call_with_stack from __irq_svc+0x9c/0xbc
[ 88.772576] Exception stack(0xd0385d40 to 0xd0385d88)
[ 88.778458] 5d40: 00000005 00000488 00000000 00000000 c208c0c0
00006402 c208b800 c1874ff0
[ 88.787451] 5d60: 00000000 c208c0c0 c1109210 c208c0d8 00000000
d0385d90 c06e068c c06e08a4
[ 88.796305] 5d80: 60000013 ffffffff
[ 88.800369] __irq_svc from omap3_noncore_dpll_program+0x3f8/0x5ec
[ 88.807588] omap3_noncore_dpll_program from clk_change_rate+0x23c/0x4f8
[ 88.815375] clk_change_rate from clk_core_set_rate_nolock+0x1b0/0x29c
[ 88.822936] clk_core_set_rate_nolock from clk_set_rate+0x30/0x64
[ 88.830056] clk_set_rate from _set_opp+0x254/0x51c
[ 88.835835] _set_opp from dev_pm_opp_set_rate+0xec/0x228
[ 88.842073] dev_pm_opp_set_rate from __cpufreq_driver_target+0x584/0x700
[ 88.849792] __cpufreq_driver_target from od_dbs_update+0xb4/0x168
[ 88.856953] od_dbs_update from dbs_work_handler+0x2c/0x60
[ 88.863441] dbs_work_handler from process_one_work+0x284/0x72c
[ 88.870411] process_one_work from worker_thread+0x28/0x4b0
[ 88.876973] worker_thread from kthread+0xe4/0x104
[ 88.882692] kthread from ret_from_fork+0x14/0x28
[ 88.888225] Exception stack(0xd0385fb0 to 0xd0385ff8)
[ 88.893998] 5fa0: 00000000
00000000 00000000 00000000
[ 88.902971] 5fc0: 00000000 00000000 00000000 00000000 00000000
00000000 00000000 00000000
[ 88.911888] 5fe0: 00000000 00000000 00000000 00000000 00000013 00000000
Regards,
Yegor
