multiple wireguard interface and kworker ressources

[nicolas prochazka]

hello,
after create of wg interface, kworker thread does not return to a
normal state in my case,
kernel thread continues to consume a lot of cpu .
I must delete wireguard interface to kworker decrease.

Nicolas

2017-06-13 23:47 GMT+02:00 Jason A. Donenfeld <Jason at zx2c4.com>:
> Hi Nicolas,
>
> It looks to me like some resources are indeed expended in adding those
> interfaces. Not that much that would be problematic -- are you seeing
> a problematic case? -- but still a non-trivial amount.
>
> I tracked it down to WireGuard's instantiation of xt_hashlimit, which
> does some ugly vmalloc, and it's call into the power state
> notification system, which uses a naive O(n) algorithm for insertion.
> I might have a way of amortizing on module insertion, which would
> speed things up. But I wonder -- what is the practical detriment of
> spending a few extra cycles on `ip link add`? What's your use case
> where this would actually be a problem?
>
> Thanks,
> Jason