From: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
To: davem@davemloft.net
Cc: Jesse Brandeburg <jesse.brandeburg@intel.com>,
netdev@vger.kernel.org, gospo@redhat.com, sassmann@redhat.com,
Catherine Sullivan <catherine.sullivan@intel.com>,
Jeff Kirsher <jeffrey.t.kirsher@intel.com>
Subject: [net-next v2 11/12] i40e/i40evf: carefully fill tx ring
Date: Thu, 6 Mar 2014 18:59:23 -0800 [thread overview]
Message-ID: <1394161164-26645-12-git-send-email-jeffrey.t.kirsher@intel.com> (raw)
In-Reply-To: <1394161164-26645-1-git-send-email-jeffrey.t.kirsher@intel.com>
From: Jesse Brandeburg <jesse.brandeburg@intel.com>
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 <jesse.brandeburg@intel.com>
Signed-off-by: Catherine Sullivan <catherine.sullivan@intel.com>
Tested-by: Kavindya Deegala <kavindya.s.deegala@intel.com>
Signed-off-by: Jeff Kirsher <jeffrey.t.kirsher@intel.com>
---
drivers/net/ethernet/intel/i40e/i40e_txrx.c | 4 ++--
drivers/net/ethernet/intel/i40evf/i40e_txrx.c | 4 ++--
2 files changed, 4 insertions(+), 4 deletions(-)
diff --git a/drivers/net/ethernet/intel/i40e/i40e_txrx.c b/drivers/net/ethernet/intel/i40e/i40e_txrx.c
index e4497f8..2081bdb 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 01bfab7..b1d87c6 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;
}
--
1.8.3.1
next prev parent reply other threads:[~2014-03-07 2:59 UTC|newest]
Thread overview: 16+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-03-07 2:59 [net-next v2 00/12][pull request] Intel Wired LAN Driver Updates Jeff Kirsher
2014-03-07 2:59 ` [net-next v2 01/12] i40evf: Enable the ndo_set_features netdev op Jeff Kirsher
2014-03-07 2:59 ` [net-next v2 02/12] i40e: Flow Director sideband accounting Jeff Kirsher
2014-03-07 2:59 ` [net-next v2 03/12] i40e: Prevent overflow due to kzalloc Jeff Kirsher
2014-03-07 2:59 ` [net-next v2 04/12] i40e/i40evf: i40e implementation for skb_set_hash Jeff Kirsher
2014-03-07 2:59 ` [net-next v2 05/12] i40e: clean up comment style Jeff Kirsher
2014-03-07 2:59 ` [net-next v2 06/12] i40e: Remove a FW workaround for Number of MSIX vectors Jeff Kirsher
2014-03-07 2:59 ` [net-next v2 07/12] i40e: count timeout events Jeff Kirsher
2014-03-07 2:59 ` [net-next v2 08/12] i40e: Remove a redundant filter addition Jeff Kirsher
2014-03-07 2:59 ` [net-next v2 09/12] i40e: Fix static checker warning Jeff Kirsher
2014-03-07 2:59 ` [net-next v2 10/12] i40e: fix nvm version and remove firmware report Jeff Kirsher
2014-03-07 2:59 ` Jeff Kirsher [this message]
2014-03-09 19:52 ` [net-next v2 11/12] i40e/i40evf: carefully fill tx ring Ben Hutchings
2014-03-07 2:59 ` [net-next v2 12/12] i40e/i40evf: Bump pf&vf build versions Jeff Kirsher
2014-03-07 21:19 ` [net-next v2 00/12][pull request] Intel Wired LAN Driver Updates David Miller
2014-03-07 21:37 ` Jeff Kirsher
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