From mboxrd@z Thu Jan 1 00:00:00 1970 From: Stephen Hemminger Subject: Re: How can I calculate/estimate pps(packet per seocond) and bps(bit per second) in DPDK pktg Date: Tue, 3 Nov 2015 15:28:50 -0800 Message-ID: <20151103152850.3e23f639@xeon-e3> References: <514E811C-1D85-4BB7-AA9C-C5D2B2ED6043@intel.com> <20151103140531.677eee6d@xeon-e3> Mime-Version: 1.0 Content-Type: text/plain; charset=US-ASCII Content-Transfer-Encoding: 7bit Cc: "dev@dpdk.org" To: Kyle Larose Return-path: Received: from mail-pa0-f49.google.com (mail-pa0-f49.google.com [209.85.220.49]) by dpdk.org (Postfix) with ESMTP id 78B105A06 for ; Wed, 4 Nov 2015 00:28:40 +0100 (CET) Received: by pasz6 with SMTP id z6so32508560pas.2 for ; Tue, 03 Nov 2015 15:28:40 -0800 (PST) In-Reply-To: List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" On Tue, 3 Nov 2015 17:18:31 -0500 Kyle Larose wrote: > On Tue, Nov 3, 2015 at 5:05 PM, Stephen Hemminger > wrote: > > > > > IMHO this is a bug. Other drivers don't include the CRC, and the Intel driver > > only includes CRC in count for one direction, and depends on value of stripping flag. > > > > I sent a patch to fix this because our customers didn't like it when Rx != Tx bytes > > but there was somebody who liked including CRC. > > > > It really is a Cisco versus the world thing. Juniper/Linux/BSD all do NOT include > > CRC in counters and therefore that is what should be done. > > > > Another option is to make whether or not the NIC counts the CRC in its > byte counters configurable, when supported, and also retrievable. I'm > concerned about the case where a NIC doesn't even have an option to > control whether or not it counts the CRC, and it *does* count it. In > that case, any software running on that NIC will behave > inconsistently. If it knew that it counted the CRC, it could adjust > for it. No. configuration is the enemy of usability. Why does DPDK have to behave differently than BSD and Linux, what possible value could this be to the end user? > If we put the option in now, then software written now could deal with > it gracefully. Combined with the ability to configure it, this may > satisfy use cases where knowing the full frame size is useful (for > example when looking at bit rates with small packets. 4 bytes is a big > difference for a 64-byte frame). > > Of course, this may not be a problem worth solving. But, I figure it's > worth considering.