From mboxrd@z Thu Jan 1 00:00:00 1970 From: "John Daley (johndale)" Subject: Re: [PATCH 2/4] enic: set the max allowed MTU for the NIC Date: Fri, 24 Jun 2016 22:42:59 +0000 Message-ID: References: <1466140969-5580-1-git-send-email-johndale@cisco.com> <1466140969-5580-3-git-send-email-johndale@cisco.com> <20160624105919.GD13456@bricha3-MOBL3> <20160624110103.GE13456@bricha3-MOBL3> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Cc: "dev@dpdk.org" To: Bruce Richardson Return-path: Received: from alln-iport-5.cisco.com (alln-iport-5.cisco.com [173.37.142.92]) by dpdk.org (Postfix) with ESMTP id 927ABC660 for ; Sat, 25 Jun 2016 00:43:01 +0200 (CEST) In-Reply-To: <20160624110103.GE13456@bricha3-MOBL3> Content-Language: en-US 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" Hi Bruce, > > * What was the MTU set to by default before this patch is applied? Was > > it just set to 1518 or something else? > > * What happens, if anything, if buffers bigger than the MTU size are se= nt > down? > This is obviously referring to buffers bigger than MTU on TX. There is al= so the > question of what happens if buffer sizes smaller than MTU are provided on > RX. I think I answered all your questions in the revised commit messages of the= v2 patchset (and then some) except this last one. Enic doesn't do any chec= king on Rx that buffers are greater than the MTU since it would affect perf= ormance. However if a packet is bigger than a buffer and Rx scatter is disa= bled, the packet will be dropped and 'imissed' incremented. Thanks, Johnd