From: Jesse Brandeburg Date: Thu, 6 Feb 2014 05:51:13 +0000 (+0000) Subject: i40e/i40evf: carefully fill tx ring X-Git-Tag: v3.15-rc1~113^2~208^2~1 X-Git-Url: https://openfabrics.org/gitweb/?a=commitdiff_plain;h=be56052154c7129e6aab0e944f3d1ab331ff0cea;p=~emulex%2Finfiniband.git i40e/i40evf: carefully fill tx ring We need to make sure that we stay away from the cache line where the DD bit (done) may be getting written back for the transmit ring since the hardware may be writing the whole cache line for a partial update. Change-ID: Id0b6dfc01f654def6a2a021af185803be1915d7e Signed-off-by: Jesse Brandeburg Signed-off-by: Catherine Sullivan Tested-by: Kavindya Deegala Signed-off-by: Jeff Kirsher --- diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c index e4497f8e117..2081bdb214e 100644 --- a/drivers/net/ethernet/intel/i40e/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40e/i40e_txrx.c @@ -2102,7 +2102,7 @@ static int i40e_xmit_descriptor_count(struct sk_buff *skb, /* need: 1 descriptor per page * PAGE_SIZE/I40E_MAX_DATA_PER_TXD, * + 1 desc for skb_head_len/I40E_MAX_DATA_PER_TXD, - * + 2 desc gap to keep tail from touching head, + * + 4 desc gap to avoid the cache line where head is, * + 1 desc for context descriptor, * otherwise try next time */ @@ -2113,7 +2113,7 @@ static int i40e_xmit_descriptor_count(struct sk_buff *skb, count += skb_shinfo(skb)->nr_frags; #endif count += TXD_USE_COUNT(skb_headlen(skb)); - if (i40e_maybe_stop_tx(tx_ring, count + 3)) { + if (i40e_maybe_stop_tx(tx_ring, count + 4 + 1)) { tx_ring->tx_stats.tx_busy++; return 0; } diff --git a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c index 01bfab729b0..b1d87c6a5c3 100644 --- a/drivers/net/ethernet/intel/i40evf/i40e_txrx.c +++ b/drivers/net/ethernet/intel/i40evf/i40e_txrx.c @@ -1482,7 +1482,7 @@ static int i40e_xmit_descriptor_count(struct sk_buff *skb, /* need: 1 descriptor per page * PAGE_SIZE/I40E_MAX_DATA_PER_TXD, * + 1 desc for skb_head_len/I40E_MAX_DATA_PER_TXD, - * + 2 desc gap to keep tail from touching head, + * + 4 desc gap to avoid the cache line where head is, * + 1 desc for context descriptor, * otherwise try next time */ @@ -1493,7 +1493,7 @@ static int i40e_xmit_descriptor_count(struct sk_buff *skb, count += skb_shinfo(skb)->nr_frags; #endif count += TXD_USE_COUNT(skb_headlen(skb)); - if (i40e_maybe_stop_tx(tx_ring, count + 3)) { + if (i40e_maybe_stop_tx(tx_ring, count + 4 + 1)) { tx_ring->tx_stats.tx_busy++; return 0; }