Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1753752AbcLBQDL (ORCPT ); Fri, 2 Dec 2016 11:03:11 -0500 Received: from mx08-00178001.pphosted.com ([91.207.212.93]:34746 "EHLO mx07-00178001.pphosted.com" rhost-flags-OK-OK-OK-FAIL) by vger.kernel.org with ESMTP id S1752087AbcLBQDJ (ORCPT ); Fri, 2 Dec 2016 11:03:09 -0500 Subject: Re: stmmac ethernet in kernel 4.9-rc6: coalescing related pauses. To: Alexandre Torgue , Pavel Machek References: <20161123105125.GA26394@amd> <20161124085506.GA25007@amd> <20161124.110416.198867271899443489.davem@davemloft.net> <20161124212540.GA24796@amd> <20161202084511.GA32294@amd> <3192a4b6-1e97-048f-a0dd-bfc0f3d96ed8@st.com> <20161202123241.GA5869@amd> <5db2ce3e-d4eb-d5d0-594c-8cd0f2e70476@st.com> CC: David Miller , , From: Giuseppe CAVALLARO Message-ID: <5627300c-a9b5-8709-bb08-5f0bceddfb05@st.com> Date: Fri, 2 Dec 2016 16:19:53 +0100 User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:45.0) Gecko/20100101 Thunderbird/45.1.0 MIME-Version: 1.0 In-Reply-To: <5db2ce3e-d4eb-d5d0-594c-8cd0f2e70476@st.com> Content-Type: text/plain; charset="windows-1252"; format=flowed Content-Transfer-Encoding: 7bit X-Originating-IP: [10.52.139.54] X-Proofpoint-Virus-Version: vendor=fsecure engine=2.50.10432:,, definitions=2016-12-02_11:,, signatures=0 Sender: linux-kernel-owner@vger.kernel.org List-ID: X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1355 Lines: 41 Hi Alex On 12/2/2016 3:26 PM, Alexandre Torgue wrote: >> 4.4 has no GMAC4 support. >> Alex, do you remember any patches to fix that? > > No sorry Peppe. > > Pavel, > > Sorry but I'm a little bit confused. I'm dropped in some mails without > historic. I see cleanup, coalescence issue and TSO question. > What is your main issue? Are you working on gmac4 or 3.x ? > Can you refresh a little bit the story please ? let me try to do a sum, please Pavel feel free to correct me. There are some open points about the tx mitigation schema that we are trying to detail and eventually tune or change (but keeping the same performance on other user-case). In particular, the test case that is raising problem is an unicast tx bench. I suggested Pavel to tune coalesce (IC bit settings) via ethtool and monitor stats but he is getting problems (maybe due to lock). IIUC problems are mainly on new kernel and not on 4.4 where the gmac4 is missing. Please Pavel, could you confirm? Then, there are some open points about lock protections for xstat and Pavel is getting some problem on SMP. I do think that we need to review that. This also could improve the code in critical parts. Also there are some other discussion about the lock protection on NAPI still under discussion. I have not clear if in this case Pavel is getting strange behavior. Regards Peppe