From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mga03.intel.com (mga03.intel.com [134.134.136.65]) by dpdk.org (Postfix) with ESMTP id 0087B2BA1 for ; Mon, 4 Jul 2016 14:25:24 +0200 (CEST) Received: from fmsmga002.fm.intel.com ([10.253.24.26]) by orsmga103.jf.intel.com with ESMTP; 04 Jul 2016 05:25:23 -0700 X-ExtLoop1: 1 X-IronPort-AV: E=Sophos;i="5.26,574,1459839600"; d="scan'208";a="1015299355" Received: from yliu-dev.sh.intel.com (HELO yliu-dev) ([10.239.67.162]) by fmsmga002.fm.intel.com with ESMTP; 04 Jul 2016 05:25:15 -0700 Date: Mon, 4 Jul 2016 20:26:30 +0800 From: Yuanhan Liu To: Jerin Jacob Cc: dev@dpdk.org, thomas.monjalon@6wind.com, bruce.richardson@intel.com, jianbo.liu@linaro.org, huawei.xie@intel.com Message-ID: <20160704122630.GB26521@yliu-dev.sh.intel.com> References: <1467028448-8914-1-git-send-email-jerin.jacob@caviumnetworks.com> <1467371814-26754-1-git-send-email-jerin.jacob@caviumnetworks.com> <1467371814-26754-2-git-send-email-jerin.jacob@caviumnetworks.com> <20160704073648.GV2831@yliu-dev.sh.intel.com> <20160704083626.GA12596@localhost.localdomain> <20160704084232.GY2831@yliu-dev.sh.intel.com> <20160704090754.GD12596@localhost.localdomain> <20160704110225.GA2831@yliu-dev.sh.intel.com> <20160704121556.GA5050@localhost.localdomain> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20160704121556.GA5050@localhost.localdomain> User-Agent: Mutt/1.5.23 (2014-03-12) Subject: Re: [dpdk-dev] [PATCH v2 1/3] virtio: conditional compilation cleanup X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: patches and discussions about DPDK List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Mon, 04 Jul 2016 12:25:25 -0000 On Mon, Jul 04, 2016 at 05:45:57PM +0530, Jerin Jacob wrote: > On Mon, Jul 04, 2016 at 07:02:25PM +0800, Yuanhan Liu wrote: > > On Mon, Jul 04, 2016 at 02:37:55PM +0530, Jerin Jacob wrote: > > > On Mon, Jul 04, 2016 at 04:42:32PM +0800, Yuanhan Liu wrote: > > > > On Mon, Jul 04, 2016 at 02:06:27PM +0530, Jerin Jacob wrote: > > > > > On Mon, Jul 04, 2016 at 03:36:48PM +0800, Yuanhan Liu wrote: > > > > > > On Fri, Jul 01, 2016 at 04:46:36PM +0530, Jerin Jacob wrote: > > > > > > > @@ -494,9 +486,6 @@ virtio_dev_tx_queue_setup(struct rte_eth_dev *dev, > > > > > > > { > > > > > > > uint8_t vtpci_queue_idx = 2 * queue_idx + VTNET_SQ_TQ_QUEUE_IDX; > > > > > > > > > > > > > > -#ifdef RTE_MACHINE_CPUFLAG_SSSE3 > > > > > > > - struct virtio_hw *hw = dev->data->dev_private; > > > > > > > -#endif > > > > > > > struct virtnet_tx *txvq; > > > > > > > struct virtqueue *vq; > > > > > > > uint16_t tx_free_thresh; > > > > > > > @@ -511,13 +500,14 @@ virtio_dev_tx_queue_setup(struct rte_eth_dev *dev, > > > > > > > } > > > > > > > > > > > > > > #ifdef RTE_MACHINE_CPUFLAG_SSSE3 > > > > > > > + struct virtio_hw *hw = dev->data->dev_private; > > > > > > > > > > > > I'd suggest to move above declaration to ... > > > > > > > > > > > > > /* Use simple rx/tx func if single segment and no offloads */ > > > > > > > if ((tx_conf->txq_flags & VIRTIO_SIMPLE_FLAGS) == VIRTIO_SIMPLE_FLAGS && > > > > > > > !vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) { > > > > > > > > > > > > here: we should try to avoid declaring vars in the middle of a code block. > > > > > > > > > > Next patch in this series, moving all rxtx handler selection code to > > > > > separate function(virtio_update_rxtx_handler()) where declaration comes > > > > > as first line in the function.i.e the comment is taken care of in the > > > > > series. > > > > > > > > Yes, I saw that. But in principle, each patch is atomic: it's not a > > > > good idea/practice to introduce issues in path A and then fix it in > > > > path B. > > > > > > In my view it was not an issue as I was removing all possible > > > conditional compilation flag. If I were to move the declaration to top > > > then another conditional compilation RTE_MACHINE_CPUFLAG_SSSE3 > > > flag I need to add around declaring the variable. > > > > Nope, I was suggesting to move it inside the "if" block. So, this > > is actually consistent with what you are trying to do. Besides, it > > removes an declaration in the middle. > > Just to get the clarity on "moving inside the 'if' block" > > Are you suggesting to have like below? > > #ifdef RTE_MACHINE_CPUFLAG_SSSE3 > + struct virtio_hw *hw; > /* Use simple rx/tx func if single segment and no offloads */ > if ((tx_conf->txq_flags & VIRTIO_SIMPLE_FLAGS) == > VIRTIO_SIMPLE_FLAGS && > !vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) { > PMD_INIT_LOG(INFO, "Using simple rx/tx path"); > dev->tx_pkt_burst = virtio_xmit_pkts_simple; > dev->rx_pkt_burst = virtio_recv_pkts_vec; > - use_simple_rxtx = 1; > + hw = dev->data->dev_private; > + hw->use_simple_rxtx = 1; > } > #endif > > > Instead of following scheme in existing patch, > > #ifdef RTE_MACHINE_CPUFLAG_SSSE3 > + struct virtio_hw *hw = dev->data->dev_private; > /* Use simple rx/tx func if single segment and no offloads */ > if ((tx_conf->txq_flags & VIRTIO_SIMPLE_FLAGS) == > VIRTIO_SIMPLE_FLAGS && > !vtpci_with_feature(hw, VIRTIO_NET_F_MRG_RXBUF)) { > PMD_INIT_LOG(INFO, "Using simple rx/tx path"); > dev->tx_pkt_burst = virtio_xmit_pkts_simple; > dev->rx_pkt_burst = virtio_recv_pkts_vec; > - use_simple_rxtx = 1; > + hw->use_simple_rxtx = 1; > } > #endif > > > The former case will have issue as "hw" been used in "if" with vtpci_with_feature. Oh, my bad. I overlooked it. Sorry for that! > OR > > if you meant just floating "struct virtio_hw *hw" without RTE_MACHINE_CPUFLAG_SSSE3 > then it comes error on non x86 as unused "hw" variable. > > If you meant something else then let me know? I then prefer to keep the "#ifdef .. #endif" on top then. It will stop us from offending a minor rule, while you can remove the ugly "#ifdef" block in the next patch. Works to you? --yliu