From patchwork Fri Jun 8 10:39:07 2018 Content-Type: text/plain; charset="utf-8" MIME-Version: 1.0 Content-Transfer-Encoding: 7bit X-Patchwork-Submitter: Maxime Coquelin X-Patchwork-Id: 40819 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 E5F055F3C; Fri, 8 Jun 2018 12:39:45 +0200 (CEST) Received: from mx1.redhat.com (mx3-rdu2.redhat.com [66.187.233.73]) by dpdk.org (Postfix) with ESMTP id DE6D22C16 for ; Fri, 8 Jun 2018 12:39:42 +0200 (CEST) Received: from smtp.corp.redhat.com (int-mx03.intmail.prod.int.rdu2.redhat.com [10.11.54.3]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 7AABE40BC056; Fri, 8 Jun 2018 10:39:42 +0000 (UTC) Received: from localhost.localdomain (ovpn-112-47.ams2.redhat.com [10.36.112.47]) by smtp.corp.redhat.com (Postfix) with ESMTP id 6CC8510F1C03; Fri, 8 Jun 2018 10:39:41 +0000 (UTC) From: Maxime Coquelin To: zhihong.wang@intel.com, tiwei.bie@intel.com, dev@dpdk.org Cc: Maxime Coquelin Date: Fri, 8 Jun 2018 12:39:07 +0200 Message-Id: <20180608103913.11517-2-maxime.coquelin@redhat.com> In-Reply-To: <20180608103913.11517-1-maxime.coquelin@redhat.com> References: <20180608103913.11517-1-maxime.coquelin@redhat.com> X-Scanned-By: MIMEDefang 2.78 on 10.11.54.3 X-Greylist: Sender IP whitelisted, not delayed by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 08 Jun 2018 10:39:42 +0000 (UTC) X-Greylist: inspected by milter-greylist-4.5.16 (mx1.redhat.com [10.11.55.7]); Fri, 08 Jun 2018 10:39:42 +0000 (UTC) for IP:'10.11.54.3' DOMAIN:'int-mx03.intmail.prod.int.rdu2.redhat.com' HELO:'smtp.corp.redhat.com' FROM:'maxime.coquelin@redhat.com' RCPT:'' Subject: [dpdk-dev] [PATCH 1/7] vhost: use shadow used ring 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" Relax used ring contention by reusing the shadow used ring feature used by enqueue path. Signed-off-by: Maxime Coquelin --- lib/librte_vhost/virtio_net.c | 45 ++++++++++--------------------------------- 1 file changed, 10 insertions(+), 35 deletions(-) diff --git a/lib/librte_vhost/virtio_net.c b/lib/librte_vhost/virtio_net.c index 98ad8e936..7e70a927f 100644 --- a/lib/librte_vhost/virtio_net.c +++ b/lib/librte_vhost/virtio_net.c @@ -1019,35 +1019,6 @@ copy_desc_to_mbuf(struct virtio_net *dev, struct vhost_virtqueue *vq, return error; } -static __rte_always_inline void -update_used_ring(struct virtio_net *dev, struct vhost_virtqueue *vq, - uint32_t used_idx, uint32_t desc_idx) -{ - vq->used->ring[used_idx].id = desc_idx; - vq->used->ring[used_idx].len = 0; - vhost_log_cache_used_vring(dev, vq, - offsetof(struct vring_used, ring[used_idx]), - sizeof(vq->used->ring[used_idx])); -} - -static __rte_always_inline void -update_used_idx(struct virtio_net *dev, struct vhost_virtqueue *vq, - uint32_t count) -{ - if (unlikely(count == 0)) - return; - - rte_smp_wmb(); - rte_smp_rmb(); - - vhost_log_cache_sync(dev, vq); - - vq->used->idx += count; - vhost_log_used_vring(dev, vq, offsetof(struct vring_used, idx), - sizeof(vq->used->idx)); - vhost_vring_call(dev, vq); -} - static __rte_always_inline struct zcopy_mbuf * get_zmbuf(struct vhost_virtqueue *vq) { @@ -1146,6 +1117,7 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id, goto out_access_unlock; vq->batch_copy_nb_elems = 0; + vq->shadow_used_idx = 0; if (dev->features & (1ULL << VIRTIO_F_IOMMU_PLATFORM)) vhost_user_iotlb_rd_lock(vq); @@ -1164,8 +1136,7 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id, if (mbuf_is_consumed(zmbuf->mbuf)) { used_idx = vq->last_used_idx++ & (vq->size - 1); - update_used_ring(dev, vq, used_idx, - zmbuf->desc_idx); + update_shadow_used_ring(vq, zmbuf->desc_idx, 0); nr_updated += 1; TAILQ_REMOVE(&vq->zmbuf_list, zmbuf, next); @@ -1176,7 +1147,9 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id, } } - update_used_idx(dev, vq, nr_updated); + flush_shadow_used_ring(dev, vq); + vhost_vring_call(dev, vq); + vq->shadow_used_idx = 0; } /* @@ -1233,7 +1206,7 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id, desc_indexes[i] = vq->avail->ring[avail_idx]; if (likely(dev->dequeue_zero_copy == 0)) - update_used_ring(dev, vq, used_idx, desc_indexes[i]); + update_shadow_used_ring(vq, desc_indexes[i], 0); } /* Prefetch descriptor index. */ @@ -1326,8 +1299,10 @@ rte_vhost_dequeue_burst(int vid, uint16_t queue_id, if (likely(dev->dequeue_zero_copy == 0)) { do_data_copy_dequeue(vq); - vq->last_used_idx += i; - update_used_idx(dev, vq, i); + if (unlikely(i < count)) + vq->shadow_used_idx = i; + flush_shadow_used_ring(dev, vq); + vhost_vring_call(dev, vq); } out: