Re: [PATCH net-next v5 17/25] ovpn: implement keepalive mechanism

On Thu, Jul 18, 2024 at 09:46:00AM +0200, Antonio Quartulli wrote:

On 18/07/2024 04:01, Andrew Lunn wrote:

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+		if (ovpn_is_keepalive(skb)) {
+			netdev_dbg(peer->ovpn->dev,
+				   "ping received from peer %u\n", peer->id);

That should probably be _ratelimited, but it seems we don't have
_ratelimited variants for the netdev_* helpers.

Right.
I have used the net_*_ratelimited() variants when needed.
Too bad we don't have those.

If you think netdev_dbg_ratelimited() would be useful, i don't see why
you cannot add it.

I just did an search and found something interesting in the history:

https://lore.kernel.org/all/20190809002941.15341-1-liuhangbin@gmail.com/T/#u (local)

Maybe limit it to netdev_dbg_ratelimited() to avoid the potential
abuse DaveM was worried about.

I see what Dave says however...

...along the packet processing routine there are several messages (some are
err or warn or info) which require ratelimiting.
Otherwise you end up with a gazilion log entries in case of a long lasting
issue.

Right now I am using net_dbg/warn/err/info_ratelimited(), therefore not
having a netdev counterpart is not really helping with Dave's argument.

Yes, i think Dave' argument is weak because these alternatives
exist. Maybe they did not at the time? 

I suspect he was using it as a way to force fixing the real issue. A
driver should not be issues lots of err or info messages. Protocol
errors are part of normal behaviour, just increment a counter and keep
going. Peer devices disappearing is normal behaviour, count it and
keep going. _err is generally reserved for something fatal happened,
and there is no recovery, other than unload the kernel module and
reload it.

	Andrew