[Bloat] Debugging a crash

[Toke Høiland-Jørgensen]

Rich Brown <richb.hanover at gmail.com> writes:

> Folks,
>
> I was running OpenWrt 19.07-rc2 on my Archer C7v2, and experienced a
> potentially-repeatable crash under heavy network traffic load.
>
> I was uploading several long videos to Youtube (> 5GBytes each) and
> watching Netflix on my 7mbps/768kbps DSL connection. Things were
> working fine (latency remained acceptable - YAY SQM!) My upstream pipe
> (slow as it is) was totally filled by the three competing uploads, and
> Netflix was doing its best to show me the West Wing.
>
> A couple times during the evening, the Netflix stream just crapped out
> and I lost the connection. (Infinite buffering message on-screen,
> couldn't get to Google, etc. The LuCI GUI showed uptime of a minute or
> so, and then things were fine again.)
>
> I now have OpenWrt 19.07.1 installed, and have a little bandwidth for
> repeating the experiment.
>
> What debugging information should I turn on/look for in case this
> happens again? Thanks.

If the box reboots, this sounds like a kernel oops. In which case, we'd
really need a kernel stack dump to debug it. Which I'm not sure there's
a good way to get on OpenWrt without attaching a serial console :(

Unless of course you can find a reliable way to reproduce it without too
much delay, in which case someone with a serial console can take a look,
I guess :)

-Toke