Hi,
We've seen these on our Goettingen Freifunk gateways, too. There, too, batadv_frag_purge_orig was the smoking gun. However, I didn't report it, because:
- first and foremost, we were using the outdated legacy 2013.4
version
We had also some other issues with older versions, so we upgraded to 2015.1 hoping the gateways will run stable.
- it was most probably an issue with RCU lists
- and either disabling SMP or using a much more current kernel fixed
it.
Did you build own kernels with disabled smp?
So I blamed a buggy RCU implementation in older kernels, plus maybe some ill behaviour in the old batman-adv codebase. The crashing kernel was the old debian-wheezy one - pretty old, I'd say.
We are running 3.16 and partially upgraded to 4.1 for testing purposes. But we have some "general protection fault: 0000 [#1] SMP" unrelated to batman also on the gateways - with different hardware. For the record, a KVM gateway (the other ones are dedicated servers without virtualization) does not crash.
Regards Bjoern