Patchwork [Precise,4/5] be2net: dont pull too much data in skb linear part

login
register
mail settings
Submitter Jesse Sung
Date Aug. 20, 2012, 3:54 a.m.
Message ID <a986c2b960b248849b89050d701e16bfc9ea53ea.1345433485.git.jesse.sung@canonical.com>
Download mbox | patch
Permalink /patch/178645/
State New
Headers show

Comments

Jesse Sung - Aug. 20, 2012, 3:54 a.m.
From: Eric Dumazet <edumazet@google.com>

BugLink: https://launchpad.net/bugs/1035348

skb_fill_rx_data() pulls 64 byte of data in skb->data

Its too much for TCP (with no options) on IPv4, as total size of headers
is 14 + 40 = 54

This means tcp stack and splice() are suboptimal, since tcp payload
is in part in tcp->data, and in part in skb frag.

Signed-off-by: Eric Dumazet <edumazet@google.com>
Acked-by: Padmanabh Ratnakar <padmanabh.ratnakar@emulex.com>
Signed-off-by: David S. Miller <davem@davemloft.net>
(cherry picked from commit ac1ae5f33fd225f46da0072e2091962410a0431b)
Signed-off-by: Wen-chien Jesse Sung <jesse.sung@canonical.com>
---
 drivers/net/ethernet/emulex/benet/be_main.c |    6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

Patch

diff --git a/drivers/net/ethernet/emulex/benet/be_main.c b/drivers/net/ethernet/emulex/benet/be_main.c
index cb4029d..b14c530 100644
--- a/drivers/net/ethernet/emulex/benet/be_main.c
+++ b/drivers/net/ethernet/emulex/benet/be_main.c
@@ -1136,16 +1136,16 @@  static void skb_fill_rx_data(struct be_adapter *adapter, struct be_rx_obj *rxo,
 	/* Copy data in the first descriptor of this completion */
 	curr_frag_len = min(rxcp->pkt_size, rx_frag_size);
 
-	/* Copy the header portion into skb_data */
-	hdr_len = min(BE_HDR_LEN, curr_frag_len);
-	memcpy(skb->data, start, hdr_len);
 	skb->len = curr_frag_len;
 	if (curr_frag_len <= BE_HDR_LEN) { /* tiny packet */
+		memcpy(skb->data, start, curr_frag_len);
 		/* Complete packet has now been moved to data */
 		put_page(page_info->page);
 		skb->data_len = 0;
 		skb->tail += curr_frag_len;
 	} else {
+		hdr_len = ETH_HLEN;
+		memcpy(skb->data, start, hdr_len);
 		skb_shinfo(skb)->nr_frags = 1;
 		skb_frag_set_page(skb, 0, page_info->page);
 		skb_shinfo(skb)->frags[0].page_offset =