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Message-Id: <1436778517-16254-5-git-send-email-jeffrey.t.kirsher@intel.com>
Date: Mon, 13 Jul 2015 02:08:25 -0700
From: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
To: davem@...emloft.net
Cc: Jesse Brandeburg <jesse.brandeburg@...el.com>,
netdev@...r.kernel.org, nhorman@...hat.com, sassmann@...hat.com,
jogreene@...hat.com, Jeff Kirsher <jeffrey.t.kirsher@...el.com>
Subject: [net-next 04/16] i40e/i40evf: improve Tx performance with a small tweak
From: Jesse Brandeburg <jesse.brandeburg@...el.com>
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 <jesse.brandeburg@...el.com>
Tested-by: Jim Young <james.m.young@...el.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@...el.com>
---
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
--
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