[Intel-wired-lan] [PATCH bpf-next v2 2/5] i40e: remove unnecessary sw_ring access from xsk Tx

Magnus Karlsson magnus.karlsson at gmail.com
Tue Nov 10 11:01:31 UTC 2020


From: Magnus Karlsson <magnus.karlsson at intel.com>

Remove the unnecessary access to the software ring for the AF_XDP
zero-copy driver. This was used to record the length of the packet so
that the driver Tx completion code could sum this up to produce the
total bytes sent. This is now performed during the transmission of the
packet, so no need to record this in the software ring.

Signed-off-by: Magnus Karlsson <magnus.karlsson at intel.com>
Acked-by: John Fastabend <john.fastabend at gmail.com>
---
 drivers/net/ethernet/intel/i40e/i40e_xsk.c | 6 +-----
 1 file changed, 1 insertion(+), 5 deletions(-)

diff --git a/drivers/net/ethernet/intel/i40e/i40e_xsk.c b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
index 6acede0..61aa1fc 100644
--- a/drivers/net/ethernet/intel/i40e/i40e_xsk.c
+++ b/drivers/net/ethernet/intel/i40e/i40e_xsk.c
@@ -392,7 +392,6 @@ static bool i40e_xmit_zc(struct i40e_ring *xdp_ring, unsigned int budget)
 {
 	unsigned int sent_frames = 0, total_bytes = 0;
 	struct i40e_tx_desc *tx_desc = NULL;
-	struct i40e_tx_buffer *tx_bi;
 	struct xdp_desc desc;
 	dma_addr_t dma;
 
@@ -404,9 +403,6 @@ static bool i40e_xmit_zc(struct i40e_ring *xdp_ring, unsigned int budget)
 		xsk_buff_raw_dma_sync_for_device(xdp_ring->xsk_pool, dma,
 						 desc.len);
 
-		tx_bi = &xdp_ring->tx_bi[xdp_ring->next_to_use];
-		tx_bi->bytecount = desc.len;
-
 		tx_desc = I40E_TX_DESC(xdp_ring, xdp_ring->next_to_use);
 		tx_desc->buffer_addr = cpu_to_le64(dma);
 		tx_desc->cmd_type_offset_bsz =
@@ -415,7 +411,7 @@ static bool i40e_xmit_zc(struct i40e_ring *xdp_ring, unsigned int budget)
 				   0, desc.len, 0);
 
 		sent_frames++;
-		total_bytes += tx_bi->bytecount;
+		total_bytes += desc.len;
 
 		xdp_ring->next_to_use++;
 		if (xdp_ring->next_to_use == xdp_ring->count)
-- 
2.7.4



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