From mboxrd@z Thu Jan 1 00:00:00 1970 From: David Miller Subject: Re: [PATCH v4 net-next 06/10] net/ncsi: Ethtool operation to get NCSI hw statistics Date: Wed, 03 May 2017 20:16:43 -0400 (EDT) Message-ID: <20170503.201643.358209122385716637.davem@davemloft.net> References: <20170503124722.GE8029@lunn.ch> <20170503.091823.747316360571887178.davem@davemloft.net> <20170504000534.GA11287@gwshan> Mime-Version: 1.0 Content-Type: Text/Plain; charset=us-ascii Content-Transfer-Encoding: 7bit Cc: andrew@lunn.ch, netdev@vger.kernel.org, joe@perches.com, kubakici@wp.pl, f.fainelli@gmail.com To: gwshan@linux.vnet.ibm.com Return-path: Received: from shards.monkeyblade.net ([184.105.139.130]:45082 "EHLO shards.monkeyblade.net" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751797AbdEDAQt (ORCPT ); Wed, 3 May 2017 20:16:49 -0400 In-Reply-To: <20170504000534.GA11287@gwshan> Sender: netdev-owner@vger.kernel.org List-ID: From: Gavin Shan Date: Thu, 4 May 2017 10:05:34 +1000 > 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. ETHTOOL_GSTATS are for device specific statistics. Whether they are fixed in your implementation or not.