net/sfc: remove few conditions in Rx queue refill

If Rx refill threshold guarantees that refill happens for one or
more bulks, less checks may be done on refill.

Signed-off-by: Andrew Rybchenko <arybchenko@solarflare.com>

diff --git a/drivers/net/sfc/sfc_rx.c b/drivers/net/sfc/sfc_rx.c
index 56e48ab..f412376 100644 (file)
--- a/drivers/net/sfc/sfc_rx.c
+++ b/drivers/net/sfc/sfc_rx.c
@@ -95,17 +95,23 @@ sfc_efx_rx_qrefill(struct sfc_efx_rxq *rxq)
                return;
 
        bulks = free_space / RTE_DIM(objs);
+       /* refill_threshold guarantees that bulks is positive */
+       SFC_ASSERT(bulks > 0);
 
        id = added & rxq->ptr_mask;
-       while (bulks-- > 0) {
-               if (rte_mempool_get_bulk(rxq->refill_mb_pool, objs,
-                                        RTE_DIM(objs)) < 0) {
+       do {
+               if (unlikely(rte_mempool_get_bulk(rxq->refill_mb_pool, objs,
+                                                 RTE_DIM(objs)) < 0)) {
                        /*
                         * It is hardly a safe way to increment counter
                         * from different contexts, but all PMDs do it.
                         */
                        rxq->evq->sa->eth_dev->data->rx_mbuf_alloc_failed +=
                                RTE_DIM(objs);
+                       /* Return if we have posted nothing yet */
+                       if (added == rxq->added)
+                               return;
+                       /* Push posted */
                        break;
                }
 
@@ -128,13 +134,11 @@ sfc_efx_rx_qrefill(struct sfc_efx_rxq *rxq)
                efx_rx_qpost(rxq->common, addr, rxq->buf_size,
                             RTE_DIM(objs), rxq->completed, added);
                added += RTE_DIM(objs);
-       }
+       } while (--bulks > 0);
 
-       /* Push doorbell if something is posted */
-       if (rxq->added != added) {
-               rxq->added = added;
-               efx_rx_qpush(rxq->common, added, &rxq->pushed);
-       }
+       SFC_ASSERT(added != rxq->added);
+       rxq->added = added;
+       efx_rx_qpush(rxq->common, added, &rxq->pushed);
 }
 
 static uint64_t
@@ -914,7 +918,8 @@ sfc_rx_qinit(struct sfc_adapter *sa, unsigned int sw_index,
 
        rxq->evq = evq;
        rxq->hw_index = sw_index;
-       rxq->refill_threshold = rx_conf->rx_free_thresh;
+       rxq->refill_threshold =
+               RTE_MAX(rx_conf->rx_free_thresh, SFC_RX_REFILL_BULK);
        rxq->refill_mb_pool = mb_pool;
 
        rc = sfc_dma_alloc(sa, "rxq", sw_index, EFX_RXQ_SIZE(rxq_info->entries),