OpenWrt/LEDE Project

  • Status Unconfirmed
  • Percent Complete
  • Task Type Bug Report
  • Category Kernel
  • Assigned To No-one
  • Operating System All
  • Severity Medium
  • Priority Very Low
  • Reported Version Trunk
  • Due in Version Undecided
  • Due Date Undecided
  • Votes 1
  • Private
Attached to Project: OpenWrt/LEDE Project
Opened by shelterx - 09.04.2019

FS#2230 - kworker spikes 100% cpu every 2 second.

Seems to happen on ar8xxx based devices, like Netgear R7800 and R7500
Also affects TP-LINK Archer C7(v4)

Present in OpenWrt SNAPSHOT, r9798-549d44736a
Also in OpenWRT 18.06 according to @nm who tried that build, but the cpu spikes seem to be 20% but they do exist.

Seems like the cpu spikes are partly because of this commit But according to the author of the original commit that removed the get_port_stats() function, reading counters are very very slow so the question is if they should be removed again, or at least have an option to disable the MiB counter checks.

For more details have have a look at the last 15 or so posts in this thread, Thanks to eveyone in the thread where this issue was brought up.

Petr Štetiar commented on 11.04.2019 22:23

FYI, Guo was fast and he has already prepared possible fix so if you're brave enough and would like to test the WIP, you're welcome.

shelterx commented on 12.04.2019 13:12

Thanks for giving the link to the commits.
I've tried it and things are much better.
CPU spikes still happen but they're back at 20%, I guess if we want MiB counters and working LEDS we have to live with it, unless it can be optimized further.

One can always disable MiB counters with swconfig, that apparently breaks the LEDs but it also makes the cpu spikes go away.


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