[dpdk-dev] [PATCH v3 0/2] Dynamically configure mempool handle

[Sergio Gonzalez Monroy]

On 15/08/2017 09:07, Santosh Shukla wrote:
> v3:
>   - Rebased on top of v17.11-rc0
>   - Updated version.map entry to v17.11.
>
> v2:
>
> DPDK has support for hw and sw mempool. Those mempool
> can work optimal for specific PMD's.
> Example:
> sw ring based PMD for Intel NICs.
> HW mempool manager dpaa2 for dpaa2 PMD.
> HW mempool manager fpa for octeontx PMD.
>
> There could be a use-case where different vendor NIC's used
> on the same platform and User like to configure mempool in such a way that
> each of those NIC's should use their preferred mempool(For performance reasons).
>
> Current mempool infrastrucure don't support such use-case.
>
> This patchset tries to address that problem in 2 steps:
>
> 0) Allowing user to dynamically configure mempool handle by
> passing pool handle as eal arg to `--mbuf-pool-ops=<pool-handle>`.
>
> 1) Allowing PMD's to advertise their preferred pool to an application.
>  From an application point of view:
> - The application must ask PMD about their preferred pool.
> - PMD to respond back with preferred pool otherwise
>    CONFIG_RTE_MEMPOOL_DEFAULT_OPS will be used for that PMD.
>
> * Application programming sequencing would be
>      char pref_mempool[RTE_MEMPOOL_OPS_NAMESIZE];
>      rte_eth_dev_get_preferred_pool_ops(ethdev_port_id, pref_mempool /* out */);
>      rte_mempool_create_empty();
>      rte_mempool_set_ops_byname( , pref_memppol, );
>      rte_mempool_populate_default();

What about introducing an API like:
rte_pktmbuf_poll_create_with_ops (..., ops_name, config_pool);

I think that API would help for the case the application wants an mbuf 
pool with ie. stack handler.
Sure we can do the empty/set_ops/populate sequence, but the only thing 
we want to change from default pktmbuf_pool_create API is the pool handler.

Application just needs to decide the ops handler to use, either default 
or one suggested by PMD?

I think ideally we would have similar APIs:
- rte_mempool_create_with_ops (...)
- rte_memppol_xmem_create_with_ops (...)


Thanks,
Sergio

> Change History:
> v2 --> v3:
>   - Changed version.map from DPDK_17.08 to DPDK_17.11.
>
> v1 --> v2:
>   - Renamed rte_eal_get_mempool_name to rte_eal_mbuf_default_mempool_ops().
> 	(suggested by Olivier)
>   - Renamed _get_preferred_pool to _get_preferred_pool_ops().
>   - Updated API description and changes return val from -EINVAL to -ENOTSUP.
>     (Suggested by Olivier)
> * Specific details on v1-->v2 change summary described in each patch.
>
> Checkpatch status:
> - None.
>
> Work History:
> * Refer [1] for v1.
>
> Thanks.
>
> [1] http://dpdk.org/ml/archives/dev/2017-June/067022.html
>
>
> Santosh Shukla (2):
>    eal: allow user to override default pool handle
>    ethdev: allow pmd to advertise pool handle
>
>   lib/librte_eal/bsdapp/eal/eal.c                 | 17 +++++++++++++++++
>   lib/librte_eal/bsdapp/eal/rte_eal_version.map   |  7 +++++++
>   lib/librte_eal/common/eal_common_options.c      |  5 +++++
>   lib/librte_eal/common/eal_internal_cfg.h        |  1 +
>   lib/librte_eal/common/eal_options.h             |  2 ++
>   lib/librte_eal/common/include/rte_eal.h         | 11 +++++++++++
>   lib/librte_eal/linuxapp/eal/eal.c               | 18 ++++++++++++++++++
>   lib/librte_eal/linuxapp/eal/rte_eal_version.map |  7 +++++++
>   lib/librte_ether/rte_ethdev.c                   | 18 ++++++++++++++++++
>   lib/librte_ether/rte_ethdev.h                   | 21 +++++++++++++++++++++
>   lib/librte_ether/rte_ether_version.map          |  7 +++++++
>   lib/librte_mbuf/rte_mbuf.c                      |  5 +++--
>   12 files changed, 117 insertions(+), 2 deletions(-)
>