From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jamal Hadi Salim Subject: Re: [RFC PATCH 00/12] RCU'ify the net:sched classifier chains Date: Sun, 12 Jan 2014 09:18:06 -0500 Message-ID: <52D2A41E.5050609@mojatatu.com> References: <20140110092041.7193.5952.stgit@nitbit.x32> <52D2987D.5060807@mojatatu.com> <52D29F4C.90808@mojatatu.com> Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8; format=flowed Content-Transfer-Encoding: 7bit Cc: netdev@vger.kernel.org, davem@davemloft.net To: John Fastabend , xiyou.wangcong@gmail.com, eric.dumazet@gmail.com Return-path: Received: from mail-ig0-f173.google.com ([209.85.213.173]:42050 "EHLO mail-ig0-f173.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750999AbaALOSK (ORCPT ); Sun, 12 Jan 2014 09:18:10 -0500 Received: by mail-ig0-f173.google.com with SMTP id ut6so3376111igb.0 for ; Sun, 12 Jan 2014 06:18:09 -0800 (PST) In-Reply-To: <52D29F4C.90808@mojatatu.com> Sender: netdev-owner@vger.kernel.org List-ID: On 01/12/14 08:57, Jamal Hadi Salim wrote: > I looked and here's a general question: > Does even using RCU make any sense here? What we have > is a lot of updates and very very little reads (reads essentially > are done from the control side; the data path is is all about updates). > > I am not sure if RCU is a win in such a case - it could make things > worse. At least that used to be the Truth(tm) many moons back. > Is that not the case anymore? > Never mind. You are not trying to make stats rcu - rather the list of filters and actions (which is read mostly from data path). Looking at the u32 piece - i think this is in the right direction. Good stuff John! cheers, jamal