Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t

[David Miller]

From: Kees Cook <keescook@xxxxxxxxxxxx>
Date: Thu, 16 Mar 2017 11:38:25 -0600

> I am, of course, biased, but I think the evidence of actual
> refcounting attacks outweighs the theoretical performance cost of
> these changes.

This is not theoretical at all.

We count the nanoseconds that every packet takes to get processed and
you are adding quite a bit.

I understand your point of view, but this is knowingly going to add
performance regressions to the networking code.