From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by dpdk.org (Postfix) with ESMTP id AF1661BB12 for ; Sat, 23 Jun 2018 09:11:51 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx06.intmail.prod.int.rdu2.redhat.com [10.11.54.6]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 56CE18A9F1; Sat, 23 Jun 2018 07:11:51 +0000 (UTC) Received: from localhost.localdomain (unknown [10.36.112.10]) by smtp.corp.redhat.com (Postfix) with ESMTP id 510B62156889; Sat, 23 Jun 2018 07:11:50 +0000 (UTC) From: Maxime Coquelin To: tiwei.bie@intel.com, zhihong.wang@intel.com, dev@dpdk.org Cc: Maxime Coquelin Date: Sat, 23 Jun 2018 09:11:27 +0200 Message-Id: <20180623071127.22999-8-maxime.coquelin@redhat.com> In-Reply-To: <20180623071127.22999-1-maxime.coquelin@redhat.com> References: <20180623071127.22999-1-maxime.coquelin@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.6 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Sat, 23 Jun 2018 07:11:51 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.2]); Sat, 23 Jun 2018 07:11:51 +0000 (UTC) for IP:'10.11.54.6' DOMAIN:'int-mx06.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'maxime.coquelin@redhat.com' RCPT:'' Subject: [dpdk-dev] [PATCH v2 7/7] vhost: improve prefetching in enqueue path X-BeenThere: dev@dpdk.org X-Mailman-Version: 2.1.15 Precedence: list List-Id: DPDK patches and discussions List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Sat, 23 Jun 2018 07:11:51 -0000 This is an optimization to prefetch next buffer while the current one is being processed. Signed-off-by: Maxime Coquelin --- lib/librte_vhost/virtio_net.c | 12 +++++++++--- 1 file changed, 9 insertions(+), 3 deletions(-) diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c index 115bb885d..2c13a59a2 100644 --- a/lib/librte_vhost/virtio_net.c +++ b/lib/librte_vhost/virtio_net.c @@ -387,6 +387,9 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq, buf_iova = buf_vec[vec_idx].buf_iova; buf_len = buf_vec[vec_idx].buf_len; + if (nr_vec > 1) + rte_prefetch0((void *)(uintptr_t)buf_vec[1].buf_addr); + if (unlikely(buf_len < dev->vhost_hlen && nr_vec <= 1)) { error = -1; goto out; @@ -398,7 +401,6 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq, hdr = &tmp_hdr; else hdr = (struct virtio_net_hdr_mrg_rxbuf *)(uintptr_t)hdr_addr; - rte_prefetch0((void *)(uintptr_t)hdr_addr); VHOST_LOG_DEBUG(VHOST_DATA, "(%d) RX: num merge buffers %d\n", dev->vid, num_buffers); @@ -430,8 +432,10 @@ copy_mbuf_to_desc(struct virtio_net *dev, struct vhost_virtqueue *vq, buf_iova = buf_vec[vec_idx].buf_iova; buf_len = buf_vec[vec_idx].buf_len; - /* Prefetch buffer address. */ - rte_prefetch0((void *)(uintptr_t)buf_addr); + /* Prefetch next buffer address. */ + if (vec_idx + 1 < nr_vec) + rte_prefetch0((void *)(uintptr_t) + buf_vec[vec_idx + 1].buf_addr); buf_offset = 0; buf_avail = buf_len; } @@ -573,6 +577,8 @@ virtio_dev_rx(struct virtio_net *dev, uint16_t queue_id, break; } + rte_prefetch0((void *)(uintptr_t)buf_vec[0].buf_addr); + VHOST_LOG_DEBUG(VHOST_DATA, "(%d) current index %d | end index %d\n", dev->vid, vq->last_avail_idx, vq->last_avail_idx + num_buffers); -- 2.14.4