From patchwork Mon Aug 20 03:54:43 2012 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit Subject: [Precise,4/5] be2net: dont pull too much data in skb linear part Date: Sun, 19 Aug 2012 17:54:43 -0000 From: Jesse Sung X-Patchwork-Id: 178645 Message-Id: To: kernel-team@lists.ubuntu.com From: Eric Dumazet 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 Acked-by: Padmanabh Ratnakar Signed-off-by: David S. Miller (cherry picked from commit ac1ae5f33fd225f46da0072e2091962410a0431b) Signed-off-by: Wen-chien Jesse Sung --- drivers/net/ethernet/emulex/benet/be_main.c | 6 +++--- 1 file changed, 3 insertions(+), 3 deletions(-) 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 =