[dpdk-dev] [PATCH] net/ice: use write combining store for tail updates on AVX512 path.

[Radu Nicolau]

Performance improvement: use a write combining store
instead of a regular mmio write to update queue tail
registers.

Signed-off-by: Radu Nicolau <radu.nico...@intel.com>
---
 drivers/net/ice/ice_rxtx_vec_avx512.c | 4 ++--
 1 file changed, 2 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ice/ice_rxtx_vec_avx512.c 
b/drivers/net/ice/ice_rxtx_vec_avx512.c
index 0e5a676e6..9f3501238 100644
--- a/drivers/net/ice/ice_rxtx_vec_avx512.c
+++ b/drivers/net/ice/ice_rxtx_vec_avx512.c
@@ -125,7 +125,7 @@ ice_rxq_rearm(struct ice_rx_queue *rxq)
                             (rxq->nb_rx_desc - 1) : (rxq->rxrearm_start - 1));
 
        /* Update the tail pointer on the NIC */
-       ICE_PCI_REG_WRITE(rxq->qrx_tail, rx_id);
+       ICE_PCI_REG_WC_WRITE(rxq->qrx_tail, rx_id);
 }
 
 static inline __m256i
@@ -1111,7 +1111,7 @@ ice_xmit_fixed_burst_vec_avx512(void *tx_queue, struct 
rte_mbuf **tx_pkts,
 
        txq->tx_tail = tx_id;
 
-       ICE_PCI_REG_WRITE(txq->qtx_tail, txq->tx_tail);
+       ICE_PCI_REG_WC_WRITE(txq->qtx_tail, txq->tx_tail);
 
        return nb_pkts;
 }
-- 
2.17.1