From mboxrd@z Thu Jan 1 00:00:00 1970 From: Gavin Shan Subject: Re: [PATCH v4 net-next 06/10] net/ncsi: Ethtool operation to get NCSI hw statistics Date: Thu, 4 May 2017 10:05:34 +1000 Message-ID: <20170504000534.GA11287@gwshan> References: <1493786681-27468-1-git-send-email-gwshan@linux.vnet.ibm.com> <1493786681-27468-7-git-send-email-gwshan@linux.vnet.ibm.com> <20170503124722.GE8029@lunn.ch> <20170503.091823.747316360571887178.davem@davemloft.net> Reply-To: Gavin Shan Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: andrew@lunn.ch, gwshan@linux.vnet.ibm.com, netdev@vger.kernel.org, joe@perches.com, kubakici@wp.pl, f.fainelli@gmail.com To: David Miller Return-path: Received: from mx0a-001b2d01.pphosted.com ([148.163.156.1]:47275 "EHLO mx0a-001b2d01.pphosted.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751753AbdEDAGg (ORCPT ); Wed, 3 May 2017 20:06:36 -0400 Received: from pps.filterd (m0098399.ppops.net [127.0.0.1]) by mx0a-001b2d01.pphosted.com (8.16.0.20/8.16.0.20) with SMTP id v4403XcM108585 for ; Wed, 3 May 2017 20:06:36 -0400 Received: from e23smtp05.au.ibm.com (e23smtp05.au.ibm.com [202.81.31.147]) by mx0a-001b2d01.pphosted.com with ESMTP id 2a7hbjcb13-1 (version=TLSv1.2 cipher=AES256-SHA bits=256 verify=NOT) for ; Wed, 03 May 2017 20:06:36 -0400 Received: from localhost by e23smtp05.au.ibm.com with IBM ESMTP SMTP Gateway: Authorized Use Only! Violators will be prosecuted for from ; Thu, 4 May 2017 10:06:33 +1000 Received: from d23av06.au.ibm.com (d23av06.au.ibm.com [9.190.235.151]) by d23relay10.au.ibm.com (8.14.9/8.14.9/NCO v10.0) with ESMTP id v4406Nxm8061194 for ; Thu, 4 May 2017 10:06:31 +1000 Received: from d23av06.au.ibm.com (localhost [127.0.0.1]) by d23av06.au.ibm.com (8.14.4/8.14.4/NCO v10.0 AVout) with ESMTP id v4405xvD020366 for ; Thu, 4 May 2017 10:05:59 +1000 Content-Disposition: inline In-Reply-To: <20170503.091823.747316360571887178.davem@davemloft.net> Sender: netdev-owner@vger.kernel.org List-ID: On Wed, May 03, 2017 at 09:18:23AM -0400, David Miller wrote: >From: Andrew Lunn >Date: Wed, 3 May 2017 14:47:22 +0200 > >> On Wed, May 03, 2017 at 02:44:37PM +1000, Gavin Shan wrote: >>> This adds ethtool command (ETHTOOL_GNCSISTATS) to retrieve the >>> NCSI hardware statistics. >> >> Hi Gavin >> >> I've not been following this patchset, so maybe i'm about to ask a >> question which has already been asked and answered. >> >> Why cannot use just use ethtool -S for this? > >Indeed, when I said to use ethtool for these NCSI hw stats I meant >that the "ethtool -S" be used, not some new ethtool command. > Thanks for the comments. Feel free to ask any questions which would make the code clear and better. There are couple of factors I thought separate command is better than ETHTOOL_GSTATS: The statistic items from ETHTOOL_GSTATS are variable, meaning the kernel needs provide the layout of the statistic items via ETHTOOL_GSSET_INFO and ETHTOOL_GSTRINGS. NCSI HW statistics aren't following this and their layout is fixed. Besides, statistics for ETHTOOL_GSTATS are maintained in local MAC, but NCSI HW statistics are collected from NIC on far-end. So they're different from this point. Lastly, the NCSI software statistics needs separate command. It'd better to have separate command for HW statistics as well, to make things consistent. Cheers, Gavin