[dpdk-dev] [RFC 0/7] changing mbuf pool handler

[Olivier Matz]

Hello,

Following discussion from [1] ("usages issue with external mempool").

This is a tentative to make the mempool_ops feature introduced
by David Hunt [2] more widely used by applications.

It applies on top of a minor fix in mbuf lib [3].

To sumarize the needs (please comment if I did not got it properly):

- new hw-assisted mempool handlers will soon be introduced
- to make use of it, the new mempool API [4] (rte_mempool_create_empty,
  rte_mempool_populate, ...) has to be used
- the legacy mempool API (rte_mempool_create) does not allow to change
  the mempool ops. The default is "ring_<s|m>p_<s|m>c" depending on
  flags.
- the mbuf helper (rte_pktmbuf_pool_create) does not allow to change
  them either, and the default is RTE_MBUF_DEFAULT_MEMPOOL_OPS
  ("ring_mp_mc")
- today, most (if not all) applications and examples use either
  rte_pktmbuf_pool_create or rte_mempool_create to create the mbuf
  pool, making it difficult to take advantage of this feature with
  existing apps.

My initial idea was to deprecate both rte_pktmbuf_pool_create() and
rte_mempool_create(), forcing the applications to use the new API, which
is more flexible. But after digging a bit, it appeared that
rte_mempool_create() is widely used, and not only for mbufs. Deprecating
it would have a big impact on applications, and replacing it with the
new API would be overkill in many use-cases.

So I finally tried the following approach (inspired from a suggestion
Jerin [5]):

- add a new mempool_ops parameter to rte_pktmbuf_pool_create(). This
  unfortunatelly breaks the API, but I implemented an ABI compat layer.
  If the patch is accepted, we could discuss how to announce/schedule
  the API change.
- update the applications and documentation to prefer
  rte_pktmbuf_pool_create() as much as possible
- update most used examples (testpmd, l2fwd, l3fwd) to add a new command
  line argument to select the mempool handler

I hope the external applications would then switch to
rte_pktmbuf_pool_create(), since it supports most of the use-cases (even
priv_size != 0, since we can call rte_mempool_obj_iter() after) .

Comments are of course welcome. Note: the patchset is not really
tested yet.


Thanks,
Olivier

[1] http://dpdk.org/ml/archives/dev/2016-July/044734.html
[2] http://dpdk.org/ml/archives/dev/2016-June/042423.html
[3] http://www.dpdk.org/dev/patchwork/patch/15923/
[4] http://dpdk.org/ml/archives/dev/2016-May/039229.html
[5] http://dpdk.org/ml/archives/dev/2016-July/044779.html


Olivier Matz (7):
  mbuf: set the handler at mbuf pool creation
  mbuf: use helper to create the pool
  testpmd: new parameter to set mbuf pool ops
  l3fwd: rework long options parsing
  l3fwd: new parameter to set mbuf pool ops
  l2fwd: rework long options parsing
  l2fwd: new parameter to set mbuf pool ops

 app/pdump/main.c                                   |   2 +-
 app/test-pipeline/init.c                           |   3 +-
 app/test-pmd/parameters.c                          |   5 +
 app/test-pmd/testpmd.c                             |  16 +-
 app/test-pmd/testpmd.h                             |   1 +
 app/test/test_cryptodev.c                          |   2 +-
 app/test/test_cryptodev_perf.c                     |   2 +-
 app/test/test_distributor.c                        |   2 +-
 app/test/test_distributor_perf.c                   |   2 +-
 app/test/test_kni.c                                |   2 +-
 app/test/test_link_bonding.c                       |   2 +-
 app/test/test_link_bonding_mode4.c                 |   2 +-
 app/test/test_link_bonding_rssconf.c               |  11 +-
 app/test/test_mbuf.c                               |   6 +-
 app/test/test_pmd_perf.c                           |   3 +-
 app/test/test_pmd_ring.c                           |   2 +-
 app/test/test_reorder.c                            |   2 +-
 app/test/test_sched.c                              |   2 +-
 app/test/test_table.c                              |   2 +-
 doc/guides/prog_guide/mbuf_lib.rst                 |   2 +-
 doc/guides/sample_app_ug/ip_reassembly.rst         |  13 +-
 doc/guides/sample_app_ug/ipv4_multicast.rst        |  12 +-
 doc/guides/sample_app_ug/l2_forward_job_stats.rst  |  33 ++--
 .../sample_app_ug/l2_forward_real_virtual.rst      |  26 ++-
 doc/guides/sample_app_ug/ptpclient.rst             |  12 +-
 doc/guides/sample_app_ug/quota_watermark.rst       |  26 ++-
 drivers/net/bonding/rte_eth_bond_8023ad.c          |  13 +-
 drivers/net/bonding/rte_eth_bond_alb.c             |   2 +-
 examples/bond/main.c                               |   2 +-
 examples/distributor/main.c                        |   2 +-
 examples/dpdk_qat/main.c                           |   3 +-
 examples/ethtool/ethtool-app/main.c                |   4 +-
 examples/exception_path/main.c                     |   3 +-
 examples/ip_fragmentation/main.c                   |   4 +-
 examples/ip_pipeline/init.c                        |  19 ++-
 examples/ip_reassembly/main.c                      |  16 +-
 examples/ipsec-secgw/ipsec-secgw.c                 |   2 +-
 examples/ipv4_multicast/main.c                     |   6 +-
 examples/kni/main.c                                |   2 +-
 examples/l2fwd-cat/l2fwd-cat.c                     |   3 +-
 examples/l2fwd-crypto/main.c                       |   2 +-
 examples/l2fwd-jobstats/main.c                     |   2 +-
 examples/l2fwd-keepalive/main.c                    |   2 +-
 examples/l2fwd/main.c                              |  36 ++++-
 examples/l3fwd-acl/main.c                          |   2 +-
 examples/l3fwd-power/main.c                        |   2 +-
 examples/l3fwd-vf/main.c                           |   2 +-
 examples/l3fwd/main.c                              | 180 +++++++++++----------
 examples/link_status_interrupt/main.c              |   2 +-
 examples/load_balancer/init.c                      |   2 +-
 .../client_server_mp/mp_server/init.c              |   3 +-
 examples/multi_process/l2fwd_fork/main.c           |  14 +-
 examples/multi_process/symmetric_mp/main.c         |   2 +-
 examples/netmap_compat/bridge/bridge.c             |   2 +-
 examples/packet_ordering/main.c                    |   2 +-
 examples/performance-thread/l3fwd-thread/main.c    |   2 +-
 examples/ptpclient/ptpclient.c                     |   3 +-
 examples/qos_meter/main.c                          |   2 +-
 examples/qos_sched/init.c                          |   2 +-
 examples/quota_watermark/qw/main.c                 |   2 +-
 examples/rxtx_callbacks/main.c                     |   2 +-
 examples/skeleton/basicfwd.c                       |   3 +-
 examples/tep_termination/main.c                    |  17 +-
 examples/vhost/main.c                              |   2 +-
 examples/vhost_xen/main.c                          |   2 +-
 examples/vmdq/main.c                               |   2 +-
 examples/vmdq_dcb/main.c                           |   2 +-
 lib/librte_mbuf/rte_mbuf.c                         |  34 +++-
 lib/librte_mbuf/rte_mbuf.h                         |  44 +++--
 lib/librte_mbuf/rte_mbuf_version.map               |   7 +
 70 files changed, 366 insertions(+), 289 deletions(-)

-- 
2.8.1