From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: [net-next v2 04/16] i40e/i40evf: improve Tx performance with a small tweak Date: Tue, 14 Jul 2015 18:30:28 -0700 Message-ID: <1436923840-24455-5-git-send-email-jeffrey.t.kirsher@intel.com> References: <1436923840-24455-1-git-send-email-jeffrey.t.kirsher@intel.com> Cc: Jesse Brandeburg , netdev@vger.kernel.org, nhorman@redhat.com, sassmann@redhat.com, jogreene@redhat.com, Jeff Kirsher To: davem@davemloft.net Return-path: Received: from mga09.intel.com ([134.134.136.24]:55935 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1752577AbbGOBap (ORCPT ); Tue, 14 Jul 2015 21:30:45 -0400 In-Reply-To: <1436923840-24455-1-git-send-email-jeffrey.t.kirsher@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: From: Jesse Brandeburg Add a prefetch for the next Tx descriptor to be used when we know there are more coming. Change-ID: Ibb9acab11d508eec2db7da795df74debc16eeacb Signed-off-by: Jesse Brandeburg Tested-by: Jim Young Signed-off-by: Jeff Kirsher --- drivers/net/ethernet/intel/i40e/i40e_txrx.c | 2 ++ drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 2 ++ 2 files changed, 4 insertions(+) diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index 9a4f2bc..1fe230d 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -2616,6 +2616,8 @@ static inline void i40e_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb, netif_xmit_stopped(netdev_get_tx_queue(tx_ring->netdev, tx_ring->queue_index))) writel(i, tx_ring->tail); + else + prefetchw(tx_desc + 1); return; diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c index 395f32f..0f0e185 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c @@ -1841,6 +1841,8 @@ static inline void i40evf_tx_map(struct i40e_ring *tx_ring, struct sk_buff *skb, netif_xmit_stopped(netdev_get_tx_queue(tx_ring->netdev, tx_ring->queue_index))) writel(i, tx_ring->tail); + else + prefetchw(tx_desc + 1); return; -- 2.4.3