Re: NOHZ tick-stop error: local softirq work is pending, handler #08!!! on Dell XPS 13 9360

Dear Anna-Maria,


Thank you very much for the support. I was finally able to collect the 
data you asked for.

Am 09.04.24 um 09:57 schrieb Anna-Maria Behnsen:

Paul Menzel writes:

[…]

quoted

Am 08.04.24 um 12:10 schrieb Anna-Maria Behnsen:

quoted

Paul Menzel writes:

quoted

quoted

On Dell XPS 13 9360/0596KF, BIOS 2.21.0 06/02/2022, with Linux 6.9-rc2+
built from commit b1e6ec0a0fd0 (Merge tag 'docs-6.9-fixes' of
git://git.lwn.net/linux) the external USB-C adapter Dell DA300 stopped
working (only the Ethernet port was used). Linux logged:

thanks for the report. Can you please provide a trace beside the dmesg
output? The following trace events should be enabled (via kernel command
line):

trace_event=timer:*,timer_migration:*,sched:sched_switch,sched:sched_wakeup,sched:sched_process_hang,irq:softirq_entry,irq:softirq_raise,irq:softirq_exit

Unfortunately I haven’t been able to reproduce it until now. Should it
happen again, I am going to try your suggestion.

Thanks for letting me know.

I wanted to configure that in the running system, but wasn’t able to set 
all of these at once with `set_event`:

     echo 
'timer:*,timer_migration:*,sched:sched_switch,sched:sched_wakeup,sched:sched_process_hang,irq:softirq_entry,irq:softirq_raise,irq:softirq_exit' 
| sudo tee /sys/kernel/tracing/set_event

For some reason setting them individually also did *not* work:

     for e in timer:* timer_migration:* sched:sched_switch 
sched:sched_wakeup sched:sched_process_hang irq:softirq_entry 
irq:softirq_raise irq:softirq_exit'; do echo "$e" | sudo tee -a 
/sys/kernel/tracing/set_event; done

I then used

     echo 1 | sudo tee /sys/kernel/tracing/events/timer/enable
     echo 1 | sudo tee /sys/kernel/tracing/events/timer_migration/enable
     echo 1 | sudo tee /sys/kernel/tracing/events/sched/sched_switch/enable
     echo 1 | sudo tee /sys/kernel/tracing/events/sched/sched_wakeup/enable
     echo 1 | sudo tee 
/sys/kernel/tracing/events/sched/sched_process_hang/enable
     echo 1 | sudo tee /sys/kernel/tracing/events/irq/softirq_entry/enable
     echo 1 | sudo tee /sys/kernel/tracing/events/irq/softirq_raise/enable
     echo 1 | sudo tee /sys/kernel/tracing/events/irq/softirq_exit/enable

and also had to increase the buffer to bridge the gap between the event 
and me noticing it:

     echo 96000 | sudo tee /sys/kernel/tracing/buffer_size_kb

Then, with Linux v6.11-rc4-11-g521b1e7f4cf0b, I was able to get the 
trace for the event below:

     [ 7542.706299] NOHZ tick-stop error: local softirq work is pending, 
handler #08!!!

$ sudo cat /sys/kernel/tracing/trace
[…]
  MediaPD~der #28-14000   [000] d..1.  7542.703768: hrtimer_cancel: 
hrtimer=000000008d2c9f3f
  MediaPD~der #28-14000   [000] .....  7542.703810: hrtimer_init: 
hrtimer=00000000c6f259e7 clockid=CLOCK_MONOTONIC mode=ABS
  MediaPD~der #28-14000   [000] d..1.  7542.703812: hrtimer_start: 
hrtimer=00000000c6f259e7 function=hrtimer_wakeup expires=7602581538204 
softexpires=7602581488204 mode=ABS
  MediaPD~der #28-14000   [000] d..2.  7542.703821: sched_switch: 
prev_comm=MediaPD~der #28 prev_pid=14000 prev_prio=120 prev_state=S ==> 
next_comm=swapper/0 next_pid=0 next_prio=120
           <idle>-0       [000] dN.2.  7542.703931: sched_wakeup: 
comm=ImageBridgeChld pid=6041 prio=120 target_cpu=000
           <idle>-0       [000] d..2.  7542.703937: sched_switch: 
prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> 
next_comm=ImageBridgeChld next_pid=6041 next_prio=120
  ImageBridgeChld-6041    [000] d..2.  7542.704041: sched_switch: 
prev_comm=ImageBridgeChld prev_pid=6041 prev_prio=120 prev_state=S ==> 
next_comm=swapper/0 next_pid=0 next_prio=120
           <idle>-0       [000] dN.2.  7542.704174: sched_wakeup: 
comm=Renderer pid=4113 prio=120 target_cpu=000
           <idle>-0       [000] d..2.  7542.704179: sched_switch: 
prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> 
next_comm=Renderer next_pid=4113 next_prio=120
         Renderer-4113    [000] d..2.  7542.704245: sched_switch: 
prev_comm=Renderer prev_pid=4113 prev_prio=120 prev_state=S ==> 
next_comm=swapper/0 next_pid=0 next_prio=120
           <idle>-0       [000] dNh2.  7542.704260: sched_wakeup: 
comm=IPC I/O Child pid=6029 prio=120 target_cpu=000
           <idle>-0       [000] d..2.  7542.704267: sched_switch: 
prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> 
next_comm=IPC I/O Child next_pid=6029 next_prio=120
    IPC I/O Child-6029    [000] d..2.  7542.704340: sched_switch: 
prev_comm=IPC I/O Child prev_pid=6029 prev_prio=120 prev_state=S ==> 
next_comm=swapper/0 next_pid=0 next_prio=120
           <idle>-0       [000] dN.2.  7542.704786: sched_wakeup: 
comm=Compositor pid=4123 prio=120 target_cpu=000
           <idle>-0       [000] d..2.  7542.704791: sched_switch: 
prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> 
next_comm=Compositor next_pid=4123 next_prio=120
       Compositor-4123    [000] d..2.  7542.704944: sched_switch: 
prev_comm=Compositor prev_pid=4123 prev_prio=120 prev_state=S ==> 
next_comm=swapper/0 next_pid=0 next_prio=120
           <idle>-0       [000] dN.2.  7542.705943: sched_wakeup: 
comm=Compositor pid=4123 prio=120 target_cpu=000
           <idle>-0       [000] d..2.  7542.705950: sched_switch: 
prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> 
next_comm=Compositor next_pid=4123 next_prio=120
       Compositor-4123    [000] d..2.  7542.706105: sched_switch: 
prev_comm=Compositor prev_pid=4123 prev_prio=120 prev_state=S ==> 
next_comm=swapper/0 next_pid=0 next_prio=120
           <idle>-0       [000] d.h2.  7542.706328: hrtimer_cancel: 
hrtimer=000000009bbda66a
           <idle>-0       [000] d.h1.  7542.706329: 
hrtimer_expire_entry: hrtimer=000000009bbda66a 
function=tick_nohz_handler now=7542584007490
           <idle>-0       [000] d.h1.  7542.706333: softirq_raise: vec=9 
[action=RCU]
           <idle>-0       [000] d.h1.  7542.706338: softirq_raise: vec=7 
[action=SCHED]
           <idle>-0       [000] d.h1.  7542.706339: hrtimer_expire_exit: 
hrtimer=000000009bbda66a
           <idle>-0       [000] d.h2.  7542.706340: hrtimer_start: 
hrtimer=000000009bbda66a function=tick_nohz_handler 
expires=7542588000000 softexpires=7542588000000 mode=ABS
           <idle>-0       [000] ..s1.  7542.706345: softirq_entry: vec=7 
[action=SCHED]
           <idle>-0       [000] ..s1.  7542.706359: softirq_exit: vec=7 
[action=SCHED]
           <idle>-0       [000] ..s1.  7542.706360: softirq_entry: vec=9 
[action=RCU]
           <idle>-0       [000] ..s1.  7542.706362: softirq_exit: vec=9 
[action=RCU]
           <idle>-0       [000] dNh4.  7542.707672: sched_wakeup: 
comm=irq/51-DLL075B: pid=194 prio=49 target_cpu=000
           <idle>-0       [000] d..2.  7542.707685: sched_switch: 
prev_comm=swapper/0 prev_pid=0 prev_prio=120 prev_state=R ==> 
next_comm=irq/51-DLL075B: next_pid=194 next_prio=49
  irq/51-DLL075B:-194     [000] .....  7542.707708: timer_init: 
timer=00000000630ae178
  irq/51-DLL075B:-194     [000] d..1.  7542.707710: timer_start: 
timer=00000000630ae178 function=process_timeout expires=4296778179 
[timeout=250] bucket_expiry=4296778184 cpu=0 idx=121 flags=
  irq/51-DLL075B:-194     [000] d..2.  7542.707718: sched_switch: 
prev_comm=irq/51-DLL075B: prev_pid=194 prev_prio=49 prev_state=D ==> 
next_comm=swapper/0 next_pid=0 next_prio=120
           <idle>-0       [000] dN.2.  7542.709072: sched_wakeup: 
comm=AudioIP~ent RPC pid=6671 prio=120 target_cpu=000
[…]

The trace file is 320 MB big. If you need the full trace and log, please 
tell me, and I’ll upload it somewhere.


Kind regards,

Paul