Re: [dpdk-dev] [PATCH v3 0/2] add support for buffered tx to ethdev

["Jastrzebski, MichalX K" <michalx.k.jastrzebski@intel.com>]

> -----Original Message-----
> From: dev [mailto:dev-bounces@dpdk.org] On Behalf Of Ananyev,
> Konstantin
> Sent: Thursday, March 10, 2016 12:32 PM
> To: Kulasek, TomaszX <tomaszx.kulasek@intel.com>; dev@dpdk.org
> Subject: Re: [dpdk-dev] [PATCH v3 0/2] add support for buffered tx to
> ethdev
> 
> > Many sample apps include internal buffering for single-packet-at-a-time
> > operation. Since this is such a common paradigm, this functionality is
> > better suited to being implemented in the ethdev API.
> >
> > The new APIs in the ethdev library are:
> > * rte_eth_tx_buffer_init - initialize buffer
> > * rte_eth_tx_buffer - buffer up a single packet for future transmission
> > * rte_eth_tx_buffer_flush - flush any unsent buffered packets
> > * rte_eth_tx_buffer_set_err_callback - set up a callback to be called in
> >   case transmitting a buffered burst fails. By default, we just free the
> >   unsent packets.
> >
> > As well as these, an additional reference callbacks are provided, which
> > frees the packets:
> >
> > * rte_eth_tx_buffer_drop_callback - silently drop packets (default
> >   behavior)
> > * rte_eth_tx_buffer_count_callback - drop and update user-provided
> counter
> >   to track the number of dropped packets
> >
> > Due to the feedback from mailing list, that buffer management facilities
> > in the user application are more preferable than API simplicity, we
> decided
> > to move internal buffer table, as well as callback functions and user data,
> > from rte_eth_dev/rte_eth_dev_data to the application space.
> > It prevents ABI breakage and gives some more flexibility in the buffer's
> > management such as allocation, dynamical size change, reuse buffers on
> many
> > ports or after fail, and so on.
> >
> >
> > The following steps illustrate how tx buffers can be used in application:
> >
> > 1) Initialization
> >
> > a) Allocate memory for a buffer
> >
> >    struct rte_eth_dev_tx_buffer *buffer = rte_zmalloc_socket("tx_buffer",
> >            RTE_ETH_TX_BUFFER_SIZE(MAX_PKT_BURST), 0, socket_id);
> >
> >    RTE_ETH_TX_BUFFER_SIZE(size) macro computes memory required to
> store
> >    "size" packets in buffer.
> >
> > b) Initialize allocated memory and set up default values. Threshold level
> >    must be lower than or equal to the MAX_PKT_BURST from 1a)
> >
> >    rte_eth_tx_buffer_init(buffer, threshold);
> >
> >
> > c) Set error callback (optional)
> >
> >    rte_eth_tx_buffer_set_err_callback(buffer, callback_fn, userdata);
> >
> >
> > 2) Store packet "pkt" in buffer and send them all to the queue_id on
> >    port_id when number of packets reaches threshold level set up in 1b)
> >
> >    rte_eth_tx_buffer(port_id, queue_id, buffer, pkt);
> >
> >
> > 3) Send all stored packets to the queue_id on port_id
> >
> >    rte_eth_tx_buffer_flush(port_id, queue_id, buffer);
> >
> >
> > 4) Flush buffer and free memory
> >
> >    rte_eth_tx_buffer_flush(port_id, queue_id, buffer);
> >    ...
> >    rte_free(buffer);
> >
> > v3 changes:
> >  - error counter removed from tx buffer structure, now default behavior is
> >    silent drop of unsent packets
> >  - some names was changed in tx buffer structure to be more descriptive
> >  - two default calbacks are provided: rte_eth_tx_buffer_drop_callback and
> >    rte_eth_tx_buffer_count_callback
> >
> > v2 changes:
> >  - reworked to use new buffer model
> >  - buffer data and callbacks are removed from
> rte_eth_dev/rte_eth_dev_data,
> >    so this patch doesn't brake an ABI anymore
> >  - introduced RTE_ETH_TX_BUFFER macro and rte_eth_tx_buffer_init
> >  - buffers are not attached to the port-queue
> >  - buffers can be allocated dynamically during application work
> >  - size of buffer can be changed without port restart
> >
> > Tomasz Kulasek (2):
> >   ethdev: add buffered tx api
> >   examples: rework to use buffered tx
> >
> >  examples/l2fwd-jobstats/main.c                     |  104 ++++------
> >  examples/l2fwd-keepalive/main.c                    |  100 ++++------
> >  examples/l2fwd/main.c                              |  104 ++++------
> >  examples/l3fwd-acl/main.c                          |   92 ++++-----
> >  examples/l3fwd-power/main.c                        |   89 ++++-----
> >  examples/link_status_interrupt/main.c              |  107 ++++------
> >  .../client_server_mp/mp_client/client.c            |  101 ++++++----
> >  examples/multi_process/l2fwd_fork/main.c           |   97 ++++-----
> >  examples/packet_ordering/main.c                    |  122 ++++++++----
> >  examples/qos_meter/main.c                          |   61 ++----
> >  lib/librte_ether/rte_ethdev.c                      |   46 +++++
> >  lib/librte_ether/rte_ethdev.h                      |  205 +++++++++++++++++++-
> >  lib/librte_ether/rte_ether_version.map             |   10 +
> >  13 files changed, 696 insertions(+), 542 deletions(-)
> >
> > --
> 
> Acked-by: Konstantin Ananyev <konstantin.ananyev@intel.com>
> 
> > 1.7.9.5

Hi Thomas,
Could You write please does this patch meet Your requirements and 
does it have a green light to be applied?