On Mon, Jul 04, 2016 at 08:26:30PM +0800, Yuanhan Liu wrote:
> 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?
OK. As you wish :-)
>
> --yliu
