From mboxrd@z Thu Jan 1 00:00:00 1970 From: Imre Palik Subject: Re: [RFC PATCH v2] bridge: make it possible for packets to traverse the bridge without hitting netfilter Date: Fri, 06 Mar 2015 11:34:29 +0100 Message-ID: <54F982B5.90108@gmail.com> References: <1424705163-13428-1-git-send-email-imrep.amz@gmail.com> <20150223160619.GF24297@breakpoint.cc> <54EEF32D.2010202@amazon.de> <20150226.113431.238255529591339000.davem@davemloft.net> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit Cc: fw@strlen.de, bridge@lists.linux-foundation.org, stephen@networkplumber.org, netdev@vger.kernel.org, linux-kernel@vger.kernel.org, aliguori@amazon.com, nbd@openwrt.org To: David Miller , imrep@amazon.de Return-path: Received: from mail-we0-f169.google.com ([74.125.82.169]:37978 "EHLO mail-we0-f169.google.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932082AbbCFKem (ORCPT ); Fri, 6 Mar 2015 05:34:42 -0500 In-Reply-To: <20150226.113431.238255529591339000.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On 02/26/15 17:34, David Miller wrote: > From: Imre Palik > Date: Thu, 26 Feb 2015 11:19:25 +0100 > >> If you are looking for peculiarities in my setup then here they are: >> I am on 4k pages, and perf is not working :-( >> (I am trying to fix those too, but that is far from being a low hanging fruit.) >> So my guess would be that the packet pipeline doesn't fit in the cache/tlb > > Pure specualtion until you can actually use perf to measure these > things. > > And I don't want to apply patches which were designed based upon > pure speculation. > I did performance measurements in the following way: Removed those pieces of the packet pipeline that I don't necessarily need one-by-one. Then measured their effect on small packet performance. This was the only part that produced considerable effect. The pure speculation was about why the effect is more than 15% increase in packet throughput, although the code path avoided contains way less code than 15% of the packet pipeline. It seems, Felix Fietkau profiled similar changes, and found my guess well founded. Now could anybody explain me what else is wrong with my patch? I run out of ideas what to improve. Thanks Imre