Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753488AbdCPTKg (ORCPT ); Thu, 16 Mar 2017 15:10:36 -0400 Received: from shards.monkeyblade.net ([184.105.139.130]:41322 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752014AbdCPTKf (ORCPT ); Thu, 16 Mar 2017 15:10:35 -0400 Date: Thu, 16 Mar 2017 12:10:32 -0700 (PDT) Message-Id: <20170316.121032.405930218798336643.davem@davemloft.net> To: keescook@chromium.org Cc: eric.dumazet@gmail.com, peterz@infradead.org, elena.reshetova@intel.com, netdev@vger.kernel.org, bridge@lists.linux-foundation.org, linux-kernel@vger.kernel.org, kuznet@ms2.inr.ac.ru, jmorris@namei.org, kaber@trash.net, stephen@networkplumber.org, ishkamiel@gmail.com, dwindsor@gmail.com Subject: Re: [PATCH 07/17] net: convert sock.sk_refcnt from atomic_t to refcount_t From: David Miller In-Reply-To: References: <1489678147-21404-8-git-send-email-elena.reshetova@intel.com> <1489683534.28631.231.camel@edumazet-glaptop3.roam.corp.google.com> X-Mailer: Mew version 6.7 on Emacs 24.5 / Mule 6.0 (HANACHIRUSATO) Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.5.12 (shards.monkeyblade.net [149.20.54.216]); Thu, 16 Mar 2017 12:10:33 -0700 (PDT) Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 475 Lines: 14 From: Kees Cook 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.