[Babel-users] babeld slashes kernel route manipulation performance by 17000%

[Juliusz Chroboczek]

> As for why you're seeing this in particular when Babel is running, now
> that we know the route dump is the culprit, it's quite obvious: While
> Babel listens for new route notifications from the kernel, it doesn't
> actually use those notifications directly; instead, it just sets a flag
> (see kernel_route_notify() in babeld.c), and does a full dump whenever
> it gets a notification.

You're right, as usual.

> Bird does things a bit differently: it will directly update its internal
> routing table from the netlink notification messages, and only does a
> full dump at intervals (by default once every minute, but it can be
> configured to run entirely without dumps).

Yeah, that's the right way.  Could you please point me at the place in
BIRD where you parse a netlink notification?

-- Juliusz