From: Leon Romanovsky <leonro@xxxxxxxxxxxx>
The following set of patches adds cross-channel (CC) support
in the libibverbs.
The cross-channel feature allows to execute WQEs that involve
cross-channel synchronization of IO operations’ on different QPs.
Complex applications usually require synchronizations for IO
operations from multiple sources before continuing their
execution.
In order to implement this, the host software usually needs
to handle completions from each one of the receive queues
(arriving in arbitrary order), process the data after last
message arrival and only then post work request on the send
queue to send the combined data to its destination.
Execution of such operation generates multiple interrupts at
an unpredictable time with an overhead of interrupts handling
and context switches.
This patchset adds synchronization primitives which gives
ability to perform conditional operations and a following
submission will introduce arithmetic calculation offload.
Synchronization abilities combined with arithmetic calculations
will allow us to program complex scenarios with a single function
call, hereby significantly reducing overhead associated with IO
processing.
Patch #1 adds CQ ignore overrun flag.
Patch #2 implements QP flags to configure master/slave properties
of queue.
Patch #3 expands work request structure to have cross-channel
specific primitives.
Patch #4 exports cross-channel device capability flag.
Patch #5 provides an example of cross-channel synchronizations.
These patches were added on top of "Completion timestamping" [1]
and "Expose QP block self multicast loopback creation flag" [2]
series.
[1] https://www.mail-archive.com/linux-rdma@xxxxxxxxxxxxxxx/msg28895.html
[2] http://comments.gmane.org/gmane.linux.drivers.rdma/30158
Changes from v0:
* Enrich cover message and commit messages.
* Add ibv_cc_pingpong example.
* Add manual to all newly created flags.
Leon Romanovsky (5):
Add CQ ignore overrun flag
Add cross-channel QP flags
Add cross-channel work requests primitives
Export cross-channel capability flag
Add an example of cross-channel synchronization
Makefile.am | 6 +-
examples/.gitignore | 1 +
examples/cc_pingpong.c | 991 +++++++++++++++++++++++++++++++++++++++++++++
include/infiniband/verbs.h | 23 +-
man/ibv_cc_pingpong.1 | 66 +++
man/ibv_create_cq_ex.3 | 18 +-
man/ibv_create_qp_ex.3 | 18 +-
man/ibv_post_send.3 | 25 +-
src/cmd.c | 5 +-
9 files changed, 1141 insertions(+), 12 deletions(-)
create mode 100644 examples/cc_pingpong.c
create mode 100644 man/ibv_cc_pingpong.1
--
1.7.12.4
--
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
