[v3,0/4] mbuf: detach mbuf with pinned external buffer

Message ID 1578993305-15165-1-git-send-email-viacheslavo@mellanox.com (mailing list archive)


Slava Ovsiienko Jan. 14, 2020, 9:15 a.m. UTC
  Today's pktmbuf pool contains only mbufs with no external buffers.
This means data buffer for the mbuf should be placed right after the
mbuf structure (+ the private data when enabled).

On some cases, the application would want to have the buffers allocated
from a different device in the platform. This is in order to do zero
copy for the packet directly to the device memory. Examples for such
devices can be GPU or storage device. For such cases the native pktmbuf
pool does not fit since each mbuf would need to point to external

To support above, the pktmbuf pool will be populated with mbuf pointing
to the device buffers using the mbuf external buffer feature.
The PMD will populate its receive queues with those buffer, so that
every packet received will be scattered directly to the device memory.
on the other direction, embedding the buffer pointer to the transmit
queues of the NIC, will make the DMA to fetch device memory
using peer to peer communication.

Such mbuf with external buffer should be handled with care when mbuf is
freed. Mainly The external buffer should not be detached, so that it can
be reused for the next packet receive.

This patch introduce a new flag on the rte_pktmbuf_pool_private
structure to specify this mempool is for mbuf with pinned external
buffer. Upon detach this flag is validated and buffer is not detached.
A new mempool create wrapper is also introduced to help application to
create and populate such mempool.

Signed-off-by: Shahaf Shuler <shahafs@mellanox.com>
Signed-off-by: Viacheslav Ovsiienko <viacheslavo@mellanox.com>

RFC: http://patches.dpdk.org/patch/63077
v1: http://patches.dpdk.org/cover/64424
v2: - fix rte_experimantal issue on comment addressing
    - rte_mbuf_has_pinned_extbuf return type is uint32_t
    - fix Power9 compilation issue
v3: - fix "#include <stdbool.h> leftover

Viacheslav Ovsiienko (4):
  mbuf: detach mbuf with pinned external buffer
  mbuf: create packet pool with external memory buffers
  app/testpmd: add mempool with external data buffers
  net/mlx5: allow use allocated mbuf with external buffer

 app/test-pmd/config.c                    |   2 +
 app/test-pmd/flowgen.c                   |   3 +-
 app/test-pmd/parameters.c                |   2 +
 app/test-pmd/testpmd.c                   |  81 +++++++++++++++++
 app/test-pmd/testpmd.h                   |   4 +-
 app/test-pmd/txonly.c                    |   3 +-
 drivers/net/mlx5/mlx5_rxq.c              |   7 +-
 drivers/net/mlx5/mlx5_rxtx.c             |   2 +-
 drivers/net/mlx5/mlx5_rxtx.h             |   2 +-
 drivers/net/mlx5/mlx5_rxtx_vec.h         |  14 +--
 drivers/net/mlx5/mlx5_rxtx_vec_altivec.h |   5 +-
 drivers/net/mlx5/mlx5_rxtx_vec_neon.h    |  29 +++---
 drivers/net/mlx5/mlx5_rxtx_vec_sse.h     |   2 +-
 lib/librte_mbuf/rte_mbuf.c               | 144 ++++++++++++++++++++++++++++-
 lib/librte_mbuf/rte_mbuf.h               | 150 +++++++++++++++++++++++++++++--
 lib/librte_mbuf/rte_mbuf_version.map     |   1 +
 16 files changed, 410 insertions(+), 41 deletions(-)