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

[Maxime Coquelin <maxime.coquelin@redhat.com>]

On 12/21/20 3:23 PM, Joyce Kong wrote:
> 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(-)
> 

Series applied to dpdk-next-virtio/main.

Thanks,
Maxime