From mboxrd@z Thu Jan 1 00:00:00 1970 From: "John Daley (johndale)" Subject: Re: [RFC] mbuf: new flag when vlan is stripped Date: Thu, 12 May 2016 20:36:36 +0000 Message-ID: References: <57222193.2040907@6wind.com> <1462897493-6567-1-git-send-email-olivier.matz@6wind.com> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable Cc: "konstantin.ananyev@intel.com" , "helin.zhang@intel.com" , "adrien.mazarguil@6wind.com" , "rahul.lakkireddy@chelsio.com" , "alejandro.lucero@netronome.com" , "sony.chacko@qlogic.com" To: Olivier Matz , "dev@dpdk.org" Return-path: Received: from rcdn-iport-4.cisco.com (rcdn-iport-4.cisco.com [173.37.86.75]) by dpdk.org (Postfix) with ESMTP id 86B6B66DB for ; Thu, 12 May 2016 22:36:38 +0200 (CEST) In-Reply-To: <1462897493-6567-1-git-send-email-olivier.matz@6wind.com> 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 Olivier, > ... > This is a draft patch that implements what was previously discussed, exce= pt > the packet_type, which does not exist for vlan today (and I think it is n= ot > mandatory for now, let's do it in another patch). >=20 > After doing this patch, it appeared that ixgbe was the only driver that h= ad a > different behavior for the PKT_RX_VLAN_PKT flag. An alternative to this > patch would be to only change the behavior of the ixgbe driver, and just > document better document the PKT_RX_VLAN_PKT flags in rte_mbuf.h > without adding new flags. I think this is a better option. >=20 > Comments are welcome. > There are applications depending on the current behavior of PKT_RX_VLAN_PKT= as confusing as it may be. I know of one that has VLAN stripping disabled= and uses the flag to determine if the packet delivered to the app has a VL= AN tag. This is actually how the flag behaves for ixgbe, and they patched e= nic and maybe other drivers to act accordingly. To avoid breaking the app (= and any others like it), I think we should keep the flag behavior the same = and add the new flag PKT_RX_VLAN_STRIPPED . We should follow on with the new packet type since it enables a nice perfor= mance improvement by not forcing apps to break open the packet just to see = if there is a VLAN tag. Thanks, john