Add packet pacing support for IB verbs

When sending from a 10G host to a 1G host, it is easy to overrun the receiver, leading to packet loss and traffic backing off. Similar problems occur when a 10G host sends data to a sub-10G virtual circuit, or a 40G host sending to a 10G host. Packet pacing could control packet injection rate and reduces network congestion to maximize throughput & minimize network latency.

Packet pacing is a rate limiting and shaping for a QP (SQ for RAW QP), set and change the rate is done by modifying QP. This series of patch made the following high level changes:
1. Report rate limit capabilities through user data. Reported capabilities
include: The maximum and minimum rate limit in kbps supported by packet pacing; Bitmap showing which QP types are supported by packet pacing operation.
2. Extend modify QP interface for growing attributes. Add rate limit support to the extended interface.
3. Enable mlx5-based hardware to be able to update the rate limit for RAW QP packet.

Available in the "topic/packet_pacing" topic branch of this git repo:
git://git.kernel.org/pub/scm/linux/kernel/git/leon/linux-rdma.git

Or for browsing:
https://git.kernel.org/cgit/linux/kernel/git/leon/linux-rdma.git/log/?h=topic/packet_pacing

Thanks,
Bodong & Leon

Bodong Wang (4):
IB/mlx5: Report mlx5 packet pacing capabilities when querying device IB/core: Support rate limit for packet pacing
IB/uverbs: Extend modify_qp and support packet pacing IB/mlx5: Update the rate limit according to user setting for RAW QP

 drivers/infiniband/core/uverbs.h      |   1 +
 drivers/infiniband/core/uverbs_cmd.c  | 178 +++++++++++++++++++++-------------
 drivers/infiniband/core/uverbs_main.c |   1 +
 drivers/infiniband/core/verbs.c       |   2 +
 drivers/infiniband/hw/mlx5/main.c     |  16 ++-
 drivers/infiniband/hw/mlx5/mlx5_ib.h  |   1 +
 drivers/infiniband/hw/mlx5/qp.c       |  71 ++++++++++++--
 include/rdma/ib_verbs.h               |   2 +
 include/uapi/rdma/ib_user_verbs.h     |  12 +++
 include/uapi/rdma/mlx5-abi.h          |  13 +++
 10 files changed, 219 insertions(+), 78 deletions(-)

--
2.7.4

--
To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to [email protected] More majordomo info at http://vger.kernel.org/majordomo-info.html