This patchset is to replace rte smp barriers in vhost 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 patchset, PVP case(vhost-user + virtio-user) has 9.8% perf uplift for the split in_order path and no perf degradation for the packed in_order path under 0.001% acceptable loss on ThunderX2 platform. [1] http://code.dpdk.org/dpdk/latest/source/doc/guides/rel_notes/deprecation.rst Joyce Kong (8): examples/vhost: relax memory ordering when enqueue/dequeue examples/vhost_blk: replace smp with thread fence vhost: remove unnecessary smp barrier for desc flags vhost: remove unnecessary smp barrier for avail idx vhost: relax full barriers for desc flags vhost: relax full barriers for used idx vhost: replace smp with thread fence for packed vring vhost: replace smp with thread fence for control path examples/vhost/virtio_net.c | 12 ++++-------- examples/vhost_blk/vhost_blk.c | 8 ++++---- lib/librte_vhost/vdpa.c | 4 ++-- lib/librte_vhost/vhost.c | 18 +++++++++--------- lib/librte_vhost/vhost.h | 6 +++--- lib/librte_vhost/vhost_user.c | 2 +- lib/librte_vhost/virtio_net.c | 26 +++++++++++--------------- 7 files changed, 34 insertions(+), 42 deletions(-) -- 2.29.2
