[dpdk-dev] [PATCH v2 0/4] DPDK ethdev callback support

[John McNamara <john.mcnamara@intel.com>]

This patchset is for a small addition to the ethdev library, to
add in support for callbacks at the RX and TX stages. This allows
packet processing to be done on packets before they get returned
to applications using rte_eth_rx_burst call.

See the RFC cover letter for the use cases:

    http://dpdk.org/ml/archives/dev/2014-December/010491.html

For the post-RFC version we spent some time investigating Stephen Hemminger's
suggestion of using the userspace RCU (read-copy-update) library for
SMP safety:

   http://urcu.so/

The default liburcu (which defaulted to liburcu-mb) requires the least
interaction from the end user but showed a 25% drop in packet throughput
in the callback sample app.

The liburcu-qsbr (quiescent state) variant showed a 1% drop in packet
throughput in the callback sample app. However it requires registered
RCU threads in the program to periodically announce quiescent states.
This makes it more difficult to implement for end user applications.

For this release we will document that adding and removing callbacks
is not thread safe.

Note: Sample application documentation to follow in a patch update.

Version 2 changes:
    * Added ABI versioning.
    * Doxygen clarifications.

Version 1 changes:
    * Added callback removal functions.
    * Minor fixes.


John McNamara (1):
  abi: Added rxtx callback functions to ABI versioning

Richardson, Bruce (3):
  ethdev: rename callbacks field to intr_cbs
  ethdev: Add in data rxtx callback support
  examples: example showing use of callbacks.

 app/test/virtual_pmd.c                 |    2 +-
 examples/rxtx_callbacks/Makefile       |   57 ++++++++
 examples/rxtx_callbacks/basicfwd.c     |  222 ++++++++++++++++++++++++++++++++
 examples/rxtx_callbacks/basicfwd.h     |   46 +++++++
 lib/librte_ether/rte_ethdev.c          |  175 ++++++++++++++++++++++++--
 lib/librte_ether/rte_ethdev.h          |  191 +++++++++++++++++++++++++++-
 lib/librte_ether/rte_ether_version.map |    4 +
 lib/librte_pmd_bond/rte_eth_bond_api.c |    2 +-
 8 files changed, 685 insertions(+), 14 deletions(-)
 create mode 100644 examples/rxtx_callbacks/Makefile
 create mode 100644 examples/rxtx_callbacks/basicfwd.c
 create mode 100644 examples/rxtx_callbacks/basicfwd.h

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1.7.4.1