[dpdk-dev] [PATCH v1 0/4] replace smp barriers in virtio with C11 atomic

[Joyce Kong <joyce.kong@arm.com>]

This patchset is to replace rte smp barriers in virtio with C11 atomic
built-ins.

The rte_smp_*mb APIs provide full barrier functionality. However, many
use cases do not require full barriers. To support such use cases, DPDK
will adopt C11 barrier semantics and provide wrappers using C11 atomic
built-ins.[1]

With this patch set, under 0.001% acceptable loss with 2 cores on vhost
side and 1 core on virtio side, PVP case(vhost-user + virtio-user) has
6.7% perf uplift for the split in_order path on ThunderX2 platform.

[1] http://code.dpdk.org/dpdk/latest/source/doc/guides/rel_notes/deprecation.rst

Joyce Kong (4):
  net/virtio: remove unnecessary rmb barrier
  net/virtio: replace smp barrier with IO barrier
  net/virtio: replace full barrier with relaxed barrier for Arm platform
  net/virtio: replace full barrier with thread fence

 drivers/net/virtio/virtio_ethdev.c | 10 ++++-----
 drivers/net/virtio/virtqueue.h     | 35 +++++++++++++++---------------
 2 files changed, 22 insertions(+), 23 deletions(-)

-- 
2.29.2