> -----Original Message-----
> From: Olivier Matz [mailto:olivier.matz at 6wind.com]
> Sent: Wednesday, February 4, 2015 5:25 PM
> To: dev at dpdk.org
> Cc: Ananyev, Konstantin; Liu, Jijiang; Zhang, Helin; olivier.matz at 6wind.com
> Subject: [PATCH v2 03/20] i40e: call i40e_txd_enable_checksum only for
> offloaded packets
>
> From i40e datasheet:
>
> The IP header type and its offload. In case of tunneling, the IIPT
> relates to the inner IP header. See also EIPT field for the outer
> (External) IP header offload.
>
> 00 - non IP packet or packet type is not defined by software
> 01 - IPv6 packet
> 10 - IPv4 packet with no IP checksum offload
> 11 - IPv4 packet with IP checksum offload
>
> Therefore it is not needed to fill the IIPT field if no offload is requested
> (we can
> keep the value to 00). For instance, the linux driver code does not set it
> when
> (skb->ip_summed != CHECKSUM_PARTIAL). We can do the same in the dpdk
> driver.
>
> The function i40e_txd_enable_checksum() that fills the offload registers can
> only be called for packets requiring an offload.
>
> Signed-off-by: Olivier Matz <olivier.matz at 6wind.com>
> ---
> lib/librte_pmd_i40e/i40e_rxtx.c | 15 +++++++++++----
> 1 file changed, 11 insertions(+), 4 deletions(-)
>
> diff --git a/lib/librte_pmd_i40e/i40e_rxtx.c b/lib/librte_pmd_i40e/i40e_rxtx.c
> index 8e9df96..9acdeee 100644
> --- a/lib/librte_pmd_i40e/i40e_rxtx.c
> +++ b/lib/librte_pmd_i40e/i40e_rxtx.c
> @@ -74,6 +74,11 @@
>
> #define I40E_TXD_CMD (I40E_TX_DESC_CMD_EOP |
> I40E_TX_DESC_CMD_RS)
>
> +#define I40E_TX_CKSUM_OFFLOAD_MASK ( \
> + PKT_TX_IP_CKSUM | \
> + PKT_TX_L4_MASK | \
> + PKT_TX_OUTER_IP_CKSUM)
> +
> #define RTE_MBUF_DATA_DMA_ADDR_DEFAULT(mb) \
> (uint64_t) ((mb)->buf_physaddr + RTE_PKTMBUF_HEADROOM)
>
> @@ -1272,10 +1277,12 @@ i40e_xmit_pkts(void *tx_queue, struct rte_mbuf
> **tx_pkts, uint16_t nb_pkts)
>
> /* Enable checksum offloading */
> cd_tunneling_params = 0;
> - i40e_txd_enable_checksum(ol_flags, &td_cmd, &td_offset,
> - l2_len, l3_len, outer_l2_len,
> - outer_l3_len,
> - &cd_tunneling_params);
> + if (ol_flags & I40E_TX_CKSUM_OFFLOAD_MASK) {
likely should be added.
> + i40e_txd_enable_checksum(ol_flags, &td_cmd, &td_offset,
> + l2_len, l3_len, outer_l2_len,
> + outer_l3_len,
> + &cd_tunneling_params);
> + }
As this code changes are in fast path, performance regression test is needed. I
would
like to see the performance difference with or without this patch set.
Hopefully nothing
different. If you need any helps, just let me know.
Regards,
Helin
>
> if (unlikely(nb_ctx)) {
> /* Setup TX context descriptor if required */
> --
> 2.1.4
