From patchwork Wed Jun 27 14:49:57 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxime Coquelin X-Patchwork-Id: 41670 X-Patchwork-Delegate: maxime.coquelin@redhat.com Return-Path: X-Original-To: patchwork@dpdk.org Delivered-To: patchwork@dpdk.org Received: from [92.243.14.124] (localhost [127.0.0.1]) by dpdk.org (Postfix) with ESMTP id B0A941BF66; Wed, 27 Jun 2018 16:50:26 +0200 (CEST) Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by dpdk.org (Postfix) with ESMTP id F07411BF4B for ; Wed, 27 Jun 2018 16:50:19 +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 9621F401022E; Wed, 27 Jun 2018 14:50:19 +0000 (UTC) Received: from localhost.localdomain (ovpn-112-39.ams2.redhat.com [10.36.112.39]) by smtp.corp.redhat.com (Postfix) with ESMTP id 749FF20389E0; Wed, 27 Jun 2018 14:50:18 +0000 (UTC) From: Maxime Coquelin To: tiwei.bie@intel.com, zhihong.wang@intel.com, dev@dpdk.org Cc: Maxime Coquelin Date: Wed, 27 Jun 2018 16:49:57 +0200 Message-Id: <20180627144959.17277-6-maxime.coquelin@redhat.com> In-Reply-To: <20180627144959.17277-1-maxime.coquelin@redhat.com> References: <20180627144959.17277-1-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 [10.11.55.6]); Wed, 27 Jun 2018 14:50:19 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Wed, 27 Jun 2018 14:50:19 +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 v3 5/7] vhost: improve prefetching in dequeue 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: , Errors-To: dev-bounces@dpdk.org Sender: "dev" 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 | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c index 371d0e646..404968cd0 100644 --- a/lib/librte_vhost/virtio_net.c +++ b/lib/librte_vhost/virtio_net.c @@ -901,7 +901,13 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, buf_iova = buf_vec[vec_idx].buf_iova; buf_len = buf_vec[vec_idx].buf_len; - rte_prefetch0((void *)(uintptr_t)buf_addr); + /* + * Prefecth desc n + 1 buffer while + * desc n buffer is processed. + */ + 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; @@ -1133,6 +1139,8 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id, if (likely(dev->dequeue_zero_copy == 0)) update_shadow_used_ring(vq, head_idx, 0); + rte_prefetch0((void *)(uintptr_t)buf_vec[0].buf_addr); + pkts[i] = rte_pktmbuf_alloc(mbuf_pool); if (unlikely(pkts[i] == NULL)) { RTE_LOG(ERR, VHOST_DATA,