From: Maxime Coquelin <maxime.coquelin@redhat.com>
Date: Fri, 6 Jul 2018 07:04:48 +0000 (+0200)
Subject: vhost: prefetch first descriptor in dequeue path
X-Git-Url: http://git.droids-corp.org/?a=commitdiff_plain;h=c1058a6b162d0e6d9210ae2c777825c2cf7b5c59;p=dpdk.git

vhost: prefetch first descriptor in dequeue path

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
Acked-by: Tiwei Bie <tiwei.bie@intel.com>
---

diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c
index 2cfd8585c8..2662a1d324 100644
--- a/lib/librte_vhost/virtio_net.c
+++ b/lib/librte_vhost/virtio_net.c
@@ -1083,6 +1083,8 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id,
 		vq->shadow_used_idx = 0;
 	}
 
+	rte_prefetch0(&vq->avail->ring[vq->last_avail_idx & (vq->size - 1)]);
+
 	/*
 	 * Construct a RARP broadcast packet, and inject it to the "pkts"
 	 * array, to looks like that guest actually send such packet.