NOHZ tick-stop error: Non-RCU local softirq work is pending, handler #08!!!

[slymanjojo]

Curious if anybody else with tick-stop error?  

Not certain if this applies; the only change is installing Docker and Pi-Hole containerized. 

A quick read seems related to a soft interrupt of 8; 

- The only solution I could find by googling;  is:

              "Add nohz=off to the kernel parameters during boot to disable it."

 

Can I safely ignore this error message; or should I do this nohz=off to the kernel parms?

 

 

[ShadowDance]

I'd say it's safe to ignore and leave it enabled. In fact, for now I'd even advice to do exactly that. I've seen some rare errors during boot that could potentially be related to setting nohz=off (the result after these errors is an unresponsive system):

[  161.210271] rcu: INFO: rcu_preempt detected stalls on CPUs/tasks:
[  161.210847] rcu:     1-...!: (0 ticks this GP) idle=91a/1/0x4000000000000000 softirq=8639/8639 fqs=0
[  161.211649] rcu:     4-...!: (1 GPs behind) idle=c0e/1/0x4000000000000000 softirq=12686/12687 fqs=0
[  161.212443] rcu:     5-...!: (1 GPs behind) idle=5b2/1/0x4000000000000000 softirq=9198/9200 fqs=0
[  161.213217]  (detected by 2, t=15002 jiffies, g=13973, q=318)

 

I've written about nohz previously in (before being aware of the above): 

 

[slymanjojo]

@ShadowDance  Thanks for sharing.   

 

Not certain what would make the system non responsive.... 

            -   I did play with the with my external enclosures to have HD's spin down with specified timer.  

 

** And thank you for reminding me, looks like I had already asked the same question. (I must be getting old) 

 

The constant seems to be IRQ of 8.   

Tried: cat /proc/interrupts    (nothing showing  for 8)

    -Any idea how to determine what is being impacted?  (fan, USB etc..)