diff mbox

[next,v2,02/11] ixgbe: Only DMA sync frame length

Message ID 20170117163540.5423.43007.stgit@localhost.localdomain
State Accepted
Delegated to: Jeff Kirsher
Headers show

Commit Message

Alexander H Duyck Jan. 17, 2017, 4:35 p.m. UTC 
From: Alexander Duyck <alexander.h.duyck@intel.com>

On some platforms, syncing a buffer for DMA is expensive. Rather than
sync the whole 2K receive buffer, only synchronise the length of the
frame, which will typically be the MTU, or a much smaller TCP ACK.

Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
---
 drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |   10 +++++-----
 1 file changed, 5 insertions(+), 5 deletions(-)

Comments

Bowers, AndrewX Jan. 31, 2017, 5:33 p.m. UTC | #1 
> -----Original Message-----
> From: Intel-wired-lan [mailto:intel-wired-lan-bounces@lists.osuosl.org] On
> Behalf Of Alexander Duyck
> Sent: Tuesday, January 17, 2017 8:36 AM
> To: intel-wired-lan@lists.osuosl.org; Kirsher, Jeffrey T
> <jeffrey.t.kirsher@intel.com>
> Subject: [Intel-wired-lan] [next PATCH v2 02/11] ixgbe: Only DMA sync frame
> length
> 
> From: Alexander Duyck <alexander.h.duyck@intel.com>
> 
> On some platforms, syncing a buffer for DMA is expensive. Rather than sync
> the whole 2K receive buffer, only synchronise the length of the frame, which
> will typically be the MTU, or a much smaller TCP ACK.
> 
> Signed-off-by: Alexander Duyck <alexander.h.duyck@intel.com>
> ---
>  drivers/net/ethernet/intel/ixgbe/ixgbe_main.c |   10 +++++-----
>  1 file changed, 5 insertions(+), 5 deletions(-)

Tested-by: Andrew Bowers <andrewx.bowers@intel.com>
diff mbox

Patch

diff --git a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
index 452a407013ef..cfc097d07661 100644
--- a/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
+++ b/drivers/net/ethernet/intel/ixgbe/ixgbe_main.c
@@ -1858,7 +1858,7 @@  static void ixgbe_dma_sync_frag(struct ixgbe_ring *rx_ring,
 		dma_sync_single_range_for_cpu(rx_ring->dev,
 					      IXGBE_CB(skb)->dma,
 					      frag->page_offset,
-					      ixgbe_rx_bufsz(rx_ring),
+					      skb_frag_size(frag),
 					      DMA_FROM_DEVICE);
 	}
 	IXGBE_CB(skb)->dma = 0;
@@ -2000,12 +2000,11 @@  static bool ixgbe_can_reuse_rx_page(struct ixgbe_ring *rx_ring,
  **/
 static bool ixgbe_add_rx_frag(struct ixgbe_ring *rx_ring,
 			      struct ixgbe_rx_buffer *rx_buffer,
-			      union ixgbe_adv_rx_desc *rx_desc,
+			      unsigned int size,
 			      struct sk_buff *skb)
 {
 	struct page *page = rx_buffer->page;
 	unsigned char *va = page_address(page) + rx_buffer->page_offset;
-	unsigned int size = le16_to_cpu(rx_desc->wb.upper.length);
 #if (PAGE_SIZE < 8192)
 	unsigned int truesize = ixgbe_rx_bufsz(rx_ring);
 #else
@@ -2037,6 +2036,7 @@  static bool ixgbe_add_rx_frag(struct ixgbe_ring *rx_ring,
 static struct sk_buff *ixgbe_fetch_rx_buffer(struct ixgbe_ring *rx_ring,
 					     union ixgbe_adv_rx_desc *rx_desc)
 {
+	unsigned int size = le16_to_cpu(rx_desc->wb.upper.length);
 	struct ixgbe_rx_buffer *rx_buffer;
 	struct sk_buff *skb;
 	struct page *page;
@@ -2091,14 +2091,14 @@  static struct sk_buff *ixgbe_fetch_rx_buffer(struct ixgbe_ring *rx_ring,
 		dma_sync_single_range_for_cpu(rx_ring->dev,
 					      rx_buffer->dma,
 					      rx_buffer->page_offset,
-					      ixgbe_rx_bufsz(rx_ring),
+					      size,
 					      DMA_FROM_DEVICE);
 
 		rx_buffer->skb = NULL;
 	}
 
 	/* pull page into skb */
-	if (ixgbe_add_rx_frag(rx_ring, rx_buffer, rx_desc, skb)) {
+	if (ixgbe_add_rx_frag(rx_ring, rx_buffer, size, skb)) {
 		/* hand second half of page back to the ring */
 		ixgbe_reuse_rx_page(rx_ring, rx_buffer);
 	} else if (IXGBE_CB(skb)->dma == rx_buffer->dma) {