On 8/21/2016 12:47 PM, Yishai Hadas wrote: > 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(-) > The third patch, to the man pages, only added raw eth to the supported type matrix for TSO. However, the actual support clearly was intended to work with UD as well. I modified the man page patch to correct that. Applied. -- Doug Ledford <dledford@xxxxxxxxxx> GPG Key ID: 0E572FDD
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