From: Yuanhan Liu <yuanhan.liu@linux.intel.com>
To: Huawei Xie <huawei.xie@intel.com>
Cc: dev@dpdk.org, yuanhan.liu@intel.com, thomas.monjalon@6wind.com,
mst@redhat.com, jianfeng.tan@intel.com,
stephen@networkplumber.org, konstantin.ananyev@intel.com,
bruce.richardson@intel.com
Subject: Re: [dpdk-dev] [PATCH] virtio: fix idx in used ring retrieved only once
Date: Mon, 20 Jun 2016 14:27:10 +0800 [thread overview]
Message-ID: <20160620062710.GE23111@yliu-dev.sh.intel.com> (raw)
In-Reply-To: <1466015437-36809-1-git-send-email-huawei.xie@intel.com>
On Thu, Jun 16, 2016 at 02:30:37AM +0800, Huawei Xie wrote:
> - while (vq->vq_used_cons_idx != vq->vq_ring.used->idx) {
> + while (VIRTQUEUE_NUSED(vq)) {
> uint32_t idx, desc_idx, used_idx;
> struct vring_used_elem *uep;
>
> diff --git a/drivers/net/virtio/virtio_ring.h b/drivers/net/virtio/virtio_ring.h
> index 447760a..fcecc16 100644
> --- a/drivers/net/virtio/virtio_ring.h
> +++ b/drivers/net/virtio/virtio_ring.h
> @@ -79,7 +79,7 @@ struct vring_used_elem {
>
> struct vring_used {
> uint16_t flags;
> - uint16_t idx;
> + volatile uint16_t idx;
> struct vring_used_elem ring[0];
> };
>
> diff --git a/drivers/net/virtio/virtio_rxtx_simple.c b/drivers/net/virtio/virtio_rxtx_simple.c
> index 7b50119..a0ef8d2 100644
> --- a/drivers/net/virtio/virtio_rxtx_simple.c
> +++ b/drivers/net/virtio/virtio_rxtx_simple.c
> @@ -184,8 +184,7 @@ virtio_recv_pkts_vec(void *rx_queue, struct rte_mbuf **rx_pkts,
> if (unlikely(nb_pkts < RTE_VIRTIO_DESC_PER_LOOP))
> return 0;
>
> - nb_used = *(volatile uint16_t *)&vq->vq_ring.used->idx -
> - vq->vq_used_cons_idx;
> + nb_used = vq->vq_ring.used->idx - vq->vq_used_cons_idx;
How about replacing it with VIRTQUEUE_NUSED here?
--yliu
prev parent reply other threads:[~2016-06-20 6:27 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2016-06-15 18:30 Huawei Xie
2016-06-19 17:48 ` [dpdk-dev] [PATCH v2] " Huawei Xie
2016-06-20 11:46 ` Yuanhan Liu
2016-06-20 6:27 ` Yuanhan Liu [this message]
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