From mboxrd@z Thu Jan 1 00:00:00 1970 From: Thomas Monjalon Subject: Re: [PATCH] doc: announce ABI change on ethdev Date: Thu, 11 May 2017 01:17:23 +0200 Message-ID: <4458150.6A1vq6VJAK@xps> References: <20170501065812.5185-1-shahafs@mellanox.com> <20170509134004.GO16218@6wind.com> <20170509170412.GA14727@jerin> Mime-Version: 1.0 Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: 7Bit Cc: dev@dpdk.org, Jerin Jacob , Adrien Mazarguil , Konstantin Ananyev , Olivier Matz , Tomasz Kulasek To: Shahaf Shuler Return-path: Received: from out4-smtp.messagingengine.com (out4-smtp.messagingengine.com [66.111.4.28]) by dpdk.org (Postfix) with ESMTP id BACB714EC for ; Thu, 11 May 2017 01:17:24 +0200 (CEST) In-Reply-To: <20170509170412.GA14727@jerin> List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" > > > This is an ABI change notice for DPDK 17.08 in librte_ether > > > about changes in rte_eth_txmode structure. > > > > > > Currently Tx offloads are enabled by default, and can be disabled > > > using ETH_TXQ_FLAGS_NO* flags. This behaviour is not consistent with > > > the Rx side where the Rx offloads are disabled by default and enabled > > > according to bit field in rte_eth_rxmode structure. > > > > > > The proposal is to disable the Tx offloads by default, and provide > > > a way for the application to enable them in rte_eth_txmode structure. > > > Besides of making the Tx configuration API more consistent for > > > applications, PMDs will be able to provide a better out of the > > > box performance. > > > Finally, as part of the work, the ETH_TXQ_FLAGS_NO* will > > > be superseded as well. > > > > > > Signed-off-by: Shahaf Shuler > > > > Basically, TX mbuf flags like TSO and checksum offloads won't have to be > > honored by PMDs unless applications request them first while configuring the > > device, just like RX offloads. > > > > Considering more and more TX offloads will be added over time, I do not > > think expecting them all to be enabled by default is sane. There will always > > be an associated software cost in PMDs, and this solution allows > > applications to selectively enable them as needed for maximum performance. > > > > Konstantin/Olivier/Tomasz, I do not want to resume the thread about > > tx_prepare(), however this could provide an alternative means to benefit > > from improved performance when applications do not need TSO (or any other > > offload for that matter), while adding consistency to device configuration. > > > > What's your opinion? > > > > In any case I'm fine with this change: > > > > Acked-by: Adrien Mazarguil > > Acked-by: Jerin Jacob Applied, thanks