On Tue, May 01, 2018 at 06:52:18PM +0100, Ananyev, Konstantin wrote:
>
>
> > -----Original Message-----
> > From: Richardson, Bruce
> > Sent: Tuesday, May 1, 2018 3:14 PM
> > To: Xing, Beilei <beilei.x...@intel.com>; Zhang, Qi Z <qi.z.zh...@intel.com>
> > Cc: dev@dpdk.org; Yigit, Ferruh <ferruh.yi...@intel.com>; Ananyev,
> > Konstantin <konstantin.anan...@intel.com>; Richardson,
> > Bruce <bruce.richard...@intel.com>
> > Subject: [PATCH v2] net/i40e: fix Tx fn selection when using new ethdev
> > offloads
> >
> > The Tx function selection code in the driver only used the older txq
> > flags values to check whether the scalar or vector functions should be
> > used. This caused performance regressions with testpmd io-fwd as the
> > scalar path rather than the vector one was being used in the default
> > case. Fix this by changing the code to take account of new offloads and
> > deleting the defines used for the old ones.
> >
> > Fixes: 7497d3e2f777 ("net/i40e: convert to new Tx offloads API")
> >
> > Signed-off-by: Bruce Richardson <bruce.richard...@intel.com>
> > ---
> > drivers/net/i40e/i40e_rxtx.c | 39 ++++++++++++++++++---------------------
> > 1 file changed, 18 insertions(+), 21 deletions(-)
> >
> > diff --git a/drivers/net/i40e/i40e_rxtx.c b/drivers/net/i40e/i40e_rxtx.c
> > index ec1ce54ca..006f5b846 100644
> > --- a/drivers/net/i40e/i40e_rxtx.c
> > +++ b/drivers/net/i40e/i40e_rxtx.c
> > @@ -40,9 +40,6 @@
> > /* Base address of the HW descriptor ring should be 128B aligned. */
> > #define I40E_RING_BASE_ALIGN 128
> >
> > -#define I40E_SIMPLE_FLAGS ((uint32_t)ETH_TXQ_FLAGS_NOMULTSEGS | \
> > - ETH_TXQ_FLAGS_NOOFFLOADS)
> > -
> > #define I40E_TXD_CMD (I40E_TX_DESC_CMD_EOP | I40E_TX_DESC_CMD_RS)
> >
> > #ifdef RTE_LIBRTE_IEEE1588
> > @@ -2108,11 +2105,9 @@ i40e_dev_tx_queue_setup_runtime(struct rte_eth_dev
> > *dev,
> > dev->data->nb_tx_queues)) {
> > /**
> > * If it is the first queue to setup,
> > - * set all flags to default and call
> > + * set all flags and call
> > * i40e_set_tx_function.
> > */
> > - ad->tx_simple_allowed = true;
> > - ad->tx_vec_allowed = true;
> > i40e_set_tx_function_flag(dev, txq);
> > i40e_set_tx_function(dev);
> > return 0;
> > @@ -2128,9 +2123,8 @@ i40e_dev_tx_queue_setup_runtime(struct rte_eth_dev
> > *dev,
> > }
> > /* check simple tx conflict */
> > if (ad->tx_simple_allowed) {
> > - if (((txq->txq_flags & I40E_SIMPLE_FLAGS) !=
> > - I40E_SIMPLE_FLAGS) ||
> > - txq->tx_rs_thresh < RTE_PMD_I40E_TX_MAX_BURST) {
> > + if (txq->offloads != 0 ||
> > + txq->tx_rs_thresh < RTE_PMD_I40E_TX_MAX_BURST) {
> > PMD_DRV_LOG(ERR, "No-simple tx is required.");
> > return -EINVAL;
> > }
> > @@ -3080,18 +3074,21 @@ i40e_set_tx_function_flag(struct rte_eth_dev *dev,
> > struct i40e_tx_queue *txq)
> > I40E_DEV_PRIVATE_TO_ADAPTER(dev->data->dev_private);
> >
> > /* Use a simple Tx queue (no offloads, no multi segs) if possible */
> > - if (((txq->txq_flags & I40E_SIMPLE_FLAGS) == I40E_SIMPLE_FLAGS)
> > - && (txq->tx_rs_thresh >= RTE_PMD_I40E_TX_MAX_BURST)) {
> > - if (txq->tx_rs_thresh <= RTE_I40E_TX_MAX_FREE_BUF_SZ) {
> > - PMD_INIT_LOG(DEBUG, "Vector tx"
> > - " can be enabled on this txq.");
> > -
> > - } else {
> > - ad->tx_vec_allowed = false;
> > - }
> > - } else {
> > - ad->tx_simple_allowed = false;
> > - }
> > + ad->tx_simple_allowed = (txq->offloads == 0 &&
> > + txq->tx_rs_thresh >= RTE_PMD_I40E_TX_MAX_BURST);
>
> Actually after another thought - who setup txq->offloads?
> I did a quick scan, through i40e code and seems no one does.
> So now it seems not possible to enable TX offloads at all.
> Konstantin
>
> BTW, seems like rxq->offloads are not properly initialised too.
>
The offloads value should come from the app, no?
