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 9623F1B533 for ; Fri, 6 Jul 2018 09:04:57 +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 2ABF64022414; Fri, 6 Jul 2018 07:04:57 +0000 (UTC) Received: from localhost.localdomain (unknown [10.36.112.10]) by smtp.corp.redhat.com (Postfix) with ESMTP id 204B62156891; Fri, 6 Jul 2018 07:04:55 +0000 (UTC) From: Maxime Coquelin To: tiwei.bie@intel.com, zhihong.wang@intel.com, dev@dpdk.org Cc: Maxime Coquelin Date: Fri, 6 Jul 2018 09:04:47 +0200 Message-Id: <20180706070449.1946-4-maxime.coquelin@redhat.com> In-Reply-To: <20180706070449.1946-1-maxime.coquelin@redhat.com> References: <20180706070449.1946-1-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]); Fri, 06 Jul 2018 07:04:57 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.6]); Fri, 06 Jul 2018 07:04:57 +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 v4 3/5] 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: , X-List-Received-Date: Fri, 06 Jul 2018 07:04:58 -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 | 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 6339296c7..2cfd8585c 100644 --- a/lib/librte_vhost/virtio_net.c +++ b/lib/librte_vhost/virtio_net.c @@ -902,7 +902,13 @@ 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; @@ -1134,6 +1140,8 @@ 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, -- 2.14.4