net/virtio: improve perf via one-way barrier on avail flag

[dpdk.git] / lib / librte_vhost / vhost.h

diff --git a/lib/librte_vhost/vhost.h b/lib/librte_vhost/vhost.h
index 5131a97..099a0d3 100644 (file)
--- a/lib/librte_vhost/vhost.h
+++ b/lib/librte_vhost/vhost.h
@@ -344,7 +344,7 @@ vq_is_packed(struct virtio_net *dev)
 static inline bool
 desc_is_avail(struct vring_packed_desc *desc, bool wrap_counter)
 {
-       uint16_t flags = *((volatile uint16_t *) &desc->flags);
+       uint16_t flags = __atomic_load_n(&desc->flags, __ATOMIC_ACQUIRE);
 
        return wrap_counter == !!(flags & VRING_DESC_F_AVAIL) &&
                wrap_counter != !!(flags & VRING_DESC_F_USED);