From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jerin Jacob Subject: Re: [PATCH v2 2/2] ethdev: introduce Tx queue offloads API Date: Mon, 11 Sep 2017 11:51:20 +0530 Message-ID: <20170911062119.GA9342@jerin> References: <20170910104827.11da9230@xeon-e3> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Cc: Stephen Hemminger , Thomas Monjalon , "dev@dpdk.org" To: Shahaf Shuler Return-path: Received: from NAM03-BY2-obe.outbound.protection.outlook.com (mail-by2nam03on0086.outbound.protection.outlook.com [104.47.42.86]) by dpdk.org (Postfix) with ESMTP id D7D571B53 for ; Mon, 11 Sep 2017 08:21:42 +0200 (CEST) Content-Disposition: inline In-Reply-To: List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: dev-bounces@dpdk.org Sender: "dev" -----Original Message----- > Date: Mon, 11 Sep 2017 05:52:19 +0000 > From: Shahaf Shuler > To: Stephen Hemminger > CC: Thomas Monjalon , "dev@dpdk.org" > Subject: Re: [dpdk-dev] [PATCH v2 2/2] ethdev: introduce Tx queue offloads > API > > Sunday, September 10, 2017 8:48 PM, Stephen Hemminger: > > > > On Sun, 10 Sep 2017 15:07:49 +0300 > > Shahaf Shuler wrote: > > > > > Introduce a new API to configure Tx offloads. > > > > > > In the new API, offloads are divided into per-port and per-queue > > > offloads. The PMD reports capability for each of them. > > > Offloads are enabled using the existing DEV_TX_OFFLOAD_* flags. > > > To enable per-port offload, the offload should be set on both device > > > configuration and queue configuration. To enable per-queue offload, > > > the offloads can be set only on queue configuration. > > > > > > In addition the Tx offloads will be disabled by default and be enabled > > > per application needs. This will much simplify PMD management of the > > > different offloads. > > > > > > The new API does not have an equivalent for the below, benchmark > > > specific, flags: > > > > > > - ETH_TXQ_FLAGS_NOREFCOUNT > > > - ETH_TXQ_FLAGS_NOMULTMEMP > > > > > > Applications should set the ETH_TXQ_FLAGS_IGNORE flag on txq_flags > > > field in order to move to the new API. > > > > > > The old Tx offloads API is kept for the meanwhile, in order to enable > > > a smooth transition for PMDs and application to the new API. > > > > > > Signed-off-by: Shahaf Shuler > > > --- > > > > Agree on a conceptual and hardware level, that this is a property that could > > be per queue. But is there really an application that would want to have > > refcounting on one queue and not another? If application is cloning mbuf's it > > needs refcounting. One could even argue that for safety these should be > > library wide. That way if an application tried to manipulate ref count on an > > mbuf and refcountin was enabled it could be panic'd. > > Actually the refcount and multi mempool flags has no equivalent on this new API. They are not counted as offloads rather some guarantees from application side, which I agree that probably needs to by library wide. > In the current API you cannot set those per queue nor per port. I think there is intention to move those flags to some other location following this series [1] I don't think that is in following this series. It should be in this series, if we are removing a feature then we should find a way to fit that in some location as there is a use case for it[1]. Without an alternative, this patch is NACK from me. [1] http://dpdk.org/ml/archives/dev/2017-September/074475.html > > [1] > http://dpdk.org/ml/archives/dev/2017-September/074475.html > > >