Re: [PATCH v6 0/4] ethdev new offloads API

["Ananyev, Konstantin" <konstantin.ananyev@intel.com>]

> -----Original Message-----
> From: Shahaf Shuler [mailto:shahafs@mellanox.com]
> Sent: Wednesday, October 4, 2017 9:18 AM
> To: Ananyev, Konstantin <konstantin.ananyev@intel.com>; thomas@monjalon.net; arybchenko@solarflare.com;
> jerin.jacob@caviumnetworks.com; Yigit, Ferruh <ferruh.yigit@intel.com>
> Cc: dev@dpdk.org
> Subject: [PATCH v6 0/4] ethdev new offloads API
> 
> Tx offloads configuration is per queue. Tx offloads are enabled by default,
> and can be disabled using ETH_TXQ_FLAGS_NO* flags.
> This behaviour is not consistent with the Rx side where the Rx offloads
> configuration is per port. Rx offloads are disabled by default and enabled
> according to bit field in rte_eth_rxmode structure.
> 
> Moreover, considering more Tx and Rx offloads will be added
> over time, the cost of managing them all inside the PMD will be tremendous,
> as the PMD will need to check the matching for the entire offload set
> for each mbuf it handles.
> In addition, on the current approach each Rx offload added breaks the
> ABI compatibility as it requires to add entries to existing bit-fields.
> 
> The series address above issues by defining a new offloads API.
> In the new API, offloads are divided into per-port and per-queue offloads,
> with a corresponding capability for each.
> The offloads are disabled by default. Each offload can be enabled or
> disabled using the existing DEV_TX_OFFLOADS_* or DEV_RX_OFFLOADS_* flags.
> Such API will enable to easily add or remove offloads, without breaking the
> ABI compatibility.
> 
> In order to provide a smooth transition between the APIs the following actions
> were taken:
> *  The old offloads API is kept for the meanwhile.
> *  Helper function which copy from old to new API were added to ethdev,
>    enabling the PMD to support only one of the APIs.
> *  Helper function which copy from new to old API were also added,
>    to enable application to use the new API with PMD which still supports
>    the old one.
> 
> Per discussion made on the RFC of this series [1], the integration plan which was
> decided is to do the transition in two phases:
> * ethdev API will move on 17.11.
> * Apps and examples will move on 18.02.
> 
> This to enable PMD maintainers sufficient time to adopt the new API.
> 
> [1]
> http://dpdk.org/ml/archives/dev/2017-August/072643.html
> 
> on v6:
>  - Move mbuf fast free Tx offload to a seperate patch.
> 
> on v5:
>  - Fix documentation.
>  - Fix comments on port offloads configuration.
> 
> on v4:
>  - Added another patch for documentation.
>  - Fixed ETH_TXQ_FLAGS_IGNORE flag override.
>  - Clarify the description of DEV_TX_OFFLOAD_MBUF_FAST_FREE offload.
> 
> on v3:
>  - Introduce the DEV_TX_OFFLOAD_MBUF_FAST_FREE to act as an equivalent
>    for the no refcnt and single mempool flags.
>  - Fix features documentation.
>  - Fix comment style.
> 
> on v2:
>  - Taking new approach of dividing offloads into per-queue and per-port one.
>  - Postpone the Tx/Rx public struct renaming to 18.02
>  - Squash the helper functions into the Rx/Tx offloads intro patches.
> 
> Shahaf Shuler (4):
>   ethdev: introduce Rx queue offloads API
>   ethdev: introduce Tx queue offloads API
>   ethdev: add mbuf fast free Tx offload
>   doc: add details on ethdev offloads API
> 
>  doc/guides/nics/features.rst            |  66 +++++---
>  doc/guides/nics/features/default.ini    |   1 +
>  doc/guides/prog_guide/poll_mode_drv.rst |  20 +++
>  lib/librte_ether/rte_ethdev.c           | 223 +++++++++++++++++++++++++--
>  lib/librte_ether/rte_ethdev.h           |  89 ++++++++++-
>  5 files changed, 359 insertions(+), 40 deletions(-)
> 
> Series-reviewed-by: Andrew Rybchenko <arybchenko@solarflare.com>
> 
> --
Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>

> 2.12.0