Hello Miroslaw, On 10/21/2014 01:29 PM, miroslaw.walukiewicz at intel.com wrote: > From: Miroslaw Walukiewicz <miroslaw.walukiewicz at intel.com> > > The NICs supported by DPDK have a possibility to accelerate TCP > traffic by sergnention offload. The application preprares a packet > with valid TCP header with size up to 64K and NIC makes packet > segmenation generating valid checksums and TCP segments. > > The patch defines a generic support for TSO offload. > - Add new PKT_TX_TCP_SEG flag. > Only packets with this flag set in ol_flags will be handled as > TSO packets. > > - Add new fields in indicating TCP TSO segment size and TCP header len. > The TSO requires from application setting following fields in mbuf. > 1. L2 header len including MAC/VLANs/SNAP if present > 2. L3 header len including IP options > 3. L4 header len (new field) including TCP options > 4. tso_segsz (new field) the size of TCP segment > > The apllication has obligation to compute the pseudo header checksum > instead of full TCP checksum and put it in the TCP header csum field. > > Handling complexity of creation combined l2_l3_len field > a new macro RTE_MBUF_TO_L2_L3_LEN() is defined to retrieve this > part of rte_mbuf. >
The patch you submitted does not include any changes in a driver (let's say ixgbe as it is the reference) taking advantage it. So it's difficult to validate that your modifications are sufficient to implement TSO. In addition of a driver, I think that testpmd should be modified to validate your changes and give an example to people wanting to use this feature. Based on your patch, I'll try to submit a series in the coming days (maybe today if the winds are favourable) that includes the remaining patches from the original TSO series [1] that were not applied by Bruce's mbuf rework. Regards, Olivier [1] http://dpdk.org/ml/archives/dev/2014-May/002537.html