From 2d031675b2f9c9fe96893090e0c7dcead9a4fad4 Mon Sep 17 00:00:00 2001 From: Joyce Kong Date: Mon, 21 Dec 2020 23:50:29 +0800 Subject: [PATCH] vhost: remove unnecessary SMP barrier for avail idx The ordering between avail index and desc reads has been enforced by load-acquire for split vring, so smp_rmb barrier is not needed behind it. Signed-off-by: Joyce Kong Reviewed-by: Ruifeng Wang Reviewed-by: Maxime Coquelin --- lib/librte_vhost/virtio_net.c | 7 ++----- 1 file changed, 2 insertions(+), 5 deletions(-) diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c index ae67237669..c912ae354f 100644 --- a/lib/librte_vhost/virtio_net.c +++ b/lib/librte_vhost/virtio_net.c @@ -1494,13 +1494,10 @@ virtio_dev_rx_async_submit_split(struct virtio_net *dev, struct async_inflight_info *pkts_info = vq->async_pkts_info; int n_pkts = 0; - avail_head = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE); - /* - * The ordering between avail index and - * desc reads needs to be enforced. + * The ordering between avail index and desc reads need to be enforced. */ - rte_smp_rmb(); + avail_head = __atomic_load_n(&vq->avail->idx, __ATOMIC_ACQUIRE); rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]); -- 2.39.5