Hi Doug, This V1 series addresses a note coming from the list to replace a macro by a static inline function, details below. The relevant kernel patches regarding capabilities were already taken into your tree for coming kernel of 4.8. The series was tested successfully with mlx5 driver (lib, kernel) and can be accessed also from my openfabrics GIT at: git://openfabrics.org/~yishaih/libibverbs.git branch: tso_v1 Yishai In general, TSO enables an application to pass a packet with large chunk of data than the MTU to the NIC and let it breaks into small packets as part of its send flow. The TSO engine will split the packet into separate packets and insert the relevant user specified L2/L3/L4 headers automatically. This is a technique for increasing outbound throughput of high-bandwidth network connections by reducing CPU overhead. For some extra information about TSO, below link can be helpful: https://en.wikipedia.org/wiki/Large_segment_offload Verbs usage, TSO traffic is performed by ibv_post_send with opcode IBV_WR_TSO. The following information should be supplied within the associated send WR: - A pointer to the packet header. - Header size. - The maximum segment size (mss) that hardware should generate in its TSO engine. The above information required to send a TSO packet is similar to the IB kernel API. http://lxr.free-electrons.com/source/include/rdma/ib_verbs.h#L1237 The TSO capabilities as of the supported QP types, max TSO payload can be achieved upon query device. When creating a TSO eligible QP, user should supply the maximum TSO header size in order to let providers preparing their SQ buffer accordingly. This need is similar to other capabilities that are given as part of QP creation for that purpose. Changes from V0: patch #2: Change 'ibv_is_qpt_supported' to be a static inline function instead of a macro. Bodong Wang (3): Fix ibv_cmd_query_device_ex to return valid output Add support for TCP segmentation offload (TSO) Update man pages for TSO support examples/devinfo.c | 20 ++++++++++++++++++++ include/infiniband/verbs.h | 37 +++++++++++++++++++++++++++++-------- man/ibv_create_qp_ex.3 | 1 + man/ibv_post_send.3 | 36 ++++++++++++++++++++++++------------ man/ibv_query_device_ex.3 | 22 ++++++++++++++-------- src/cmd.c | 9 +-------- 6 files changed, 89 insertions(+), 36 deletions(-) -- 1.8.3.1 -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo@xxxxxxxxxxxxxxx More majordomo info at http://vger.kernel.org/majordomo-info.html
