Re: [PATCH net-next 1/5] net: add support for noref skb->sk

On Wed, 2017-09-20 at 18:54 +0200, Paolo Abeni wrote:

Noref sk do not carry a socket refcount, are valid
only inside the current RCU section and must be
explicitly cleared before exiting such section.

They will be used in a later patch to allow early demux
without sock refcounting.

+/* dummy destructor used by noref sockets */
+void sock_dummyfree(struct sk_buff *skb)
+{

BUG();

+}
+EXPORT_SYMBOL(sock_dummyfree);
+

I do not see how you ensure we do not leave RCU section with an skb
destructor pointing to this sock_dummyfree()

This patch series looks quite dangerous to me.

Do we really have real applications using connected UDP sockets and
wanting very high pps throughput ?

I am pretty sure the bottleneck is the sender part.