Hi all,
when stressing a 6.1-rt based system with network load we can
immediately see the following in the system log:
[ 165.260690] NOHZ tick-stop error: local softirq work is pending, handler #80!!!
[ 165.264689] NOHZ tick-stop error: local softirq work is pending, handler #80!!!
[ 165.268687] NOHZ tick-stop error: local softirq work is pending, handler #80!!!
...
or (from a different system)
[ 227.230611] NOHZ tick-stop error: local softirq work is pending, handler #08!!!
[ 227.231894] NOHZ tick-stop error: local softirq work is pending, handler #88!!!
[ 227.232218] NOHZ tick-stop error: local softirq work is pending, handler #88!!!
...
handler #80 means SCHED_SOFTIRQ,
handler #08 means NET_RX_SOFTIRQ
It seems that
96c1fa04f089 ("tick/rcu: Fix false positive "softirq work is pending" messages")
tried to fix this issue, but for some reason it does not work.
Is that something that is really allowed to happen on RT (which means
that one of the conditions for the warning is still wrong) or a real
problem? We did not notice any negative impact on the system so far.
Input welcome...
The warning is raised by report_idle_softirq() in kernel/time/tick-
sched.c.
Best regards,
Florian
--
Siemens AG, Foundational Technologies
Linux Expert Center
