From: Tiwei Bie <tiwei.bie@intel.com>
To: Jens Freimann <jfreimann@redhat.com>
Cc: dev@dpdk.org, maxime.coquelin@redhat.com, Gavin.Hu@arm.com,
zhihong.wang@intel.com
Subject: Re: [dpdk-dev] [PATCH v6 06/11] net/virtio: implement transmit path for packed queues
Date: Fri, 21 Sep 2018 20:26:58 +0800 [thread overview]
Message-ID: <20180921122658.GA24906@debian> (raw)
In-Reply-To: <20180921103308.16357-7-jfreimann@redhat.com>
On Fri, Sep 21, 2018 at 12:33:03PM +0200, Jens Freimann wrote:
[...]
>
> static inline int
> -desc_is_used(struct vring_desc_packed *desc, struct vring *vr)
> +_desc_is_used(struct vring_desc_packed *desc)
> {
> uint16_t used, avail;
>
> used = !!(desc->flags & VRING_DESC_F_USED(1));
> avail = !!(desc->flags & VRING_DESC_F_AVAIL(1));
>
> - return used == avail && used == vr->used_wrap_counter;
> + return used == avail;
> +
> +}
> +
> +static inline int
> +desc_is_used(struct vring_desc_packed *desc, struct vring *vr)
> +{
> + uint16_t used;
> +
> + used = !!(desc->flags & VRING_DESC_F_USED(1));
> +
> + return _desc_is_used(desc) && used == vr->used_wrap_counter;
> }
>
> /* The standard layout for the ring is a continuous chunk of memory which
> diff --git a/drivers/net/virtio/virtio_rxtx.c b/drivers/net/virtio/virtio_rxtx.c
> index eb891433e..ea6300563 100644
> --- a/drivers/net/virtio/virtio_rxtx.c
> +++ b/drivers/net/virtio/virtio_rxtx.c
> @@ -38,6 +38,7 @@
> #define VIRTIO_DUMP_PACKET(m, len) do { } while (0)
> #endif
>
> +
> int
> virtio_dev_rx_queue_done(void *rxq, uint16_t offset)
> {
> @@ -165,6 +166,31 @@ virtqueue_dequeue_rx_inorder(struct virtqueue *vq,
> #endif
>
> /* Cleanup from completed transmits. */
> +static void
> +virtio_xmit_cleanup_packed(struct virtqueue *vq)
> +{
> + uint16_t idx;
> + uint16_t size = vq->vq_nentries;
> + struct vring_desc_packed *desc = vq->vq_ring.desc_packed;
> + struct vq_desc_extra *dxp;
> +
> + idx = vq->vq_used_cons_idx;
> + while (_desc_is_used(&desc[idx]) &&
We can't just compare the AVAIL bit and USED bit to
check whether a desc is used.
> + vq->vq_free_cnt < size) {
> + dxp = &vq->vq_descx[idx];
The code is still assuming the descs will be written
back by device in order. The vq->vq_descx[] needs to
be managed e.g. as a list to support the out-of-order
processing. IOW, we can't assume vq->vq_descx[idx]
is corresponding to desc[idx] when device may write
back the descs out of order.
> + vq->vq_free_cnt += dxp->ndescs;
> + idx += dxp->ndescs;
> + idx = idx >= size ? idx - size : idx;
> + if (idx == 0) {
> + vq->vq_ring.used_wrap_counter ^= 1;
> + }
> + if (dxp->cookie != NULL) {
> + rte_pktmbuf_free(dxp->cookie);
> + dxp->cookie = NULL;
> + }
> + }
> +}
[...]
next prev parent reply other threads:[~2018-09-21 12:28 UTC|newest]
Thread overview: 18+ messages / expand[flat|nested] mbox.gz Atom feed top
2018-09-21 10:32 [dpdk-dev] [PATCH v6 00/11] implement packed virtqueues Jens Freimann
2018-09-21 10:32 ` [dpdk-dev] [PATCH v6 01/11] net/virtio: vring init for packed queues Jens Freimann
2018-09-21 10:32 ` [dpdk-dev] [PATCH v6 02/11] net/virtio: add packed virtqueue defines Jens Freimann
2018-09-21 10:33 ` [dpdk-dev] [PATCH v6 03/11] net/virtio: add packed virtqueue helpers Jens Freimann
2018-09-21 10:33 ` [dpdk-dev] [PATCH v6 04/11] net/virtio: flush packed receive virtqueues Jens Freimann
2018-09-21 10:33 ` [dpdk-dev] [PATCH v6 05/11] net/virtio: dump packed virtqueue data Jens Freimann
2018-09-21 10:33 ` [dpdk-dev] [PATCH v6 06/11] net/virtio: implement transmit path for packed queues Jens Freimann
2018-09-21 12:26 ` Tiwei Bie [this message]
2018-09-21 12:37 ` Jens Freimann
2018-09-21 12:49 ` Tiwei Bie
2018-09-21 10:33 ` [dpdk-dev] [PATCH v6 07/11] net/virtio: implement receive " Jens Freimann
2018-09-21 10:33 ` [dpdk-dev] [PATCH v6 08/11] net/virtio: add support for mergeable buffers with packed virtqueues Jens Freimann
2018-09-21 10:33 ` [dpdk-dev] [PATCH v6 09/11] net/virtio: add virtio send command packed queue support Jens Freimann
2018-09-21 12:37 ` Tiwei Bie
2018-09-21 10:33 ` [dpdk-dev] [PATCH v6 10/11] net/virtio-user: add option to use packed queues Jens Freimann
2018-09-21 10:33 ` [dpdk-dev] [PATCH v6 11/11] net/virtio: enable packed virtqueues by default Jens Freimann
2018-09-21 12:32 ` [dpdk-dev] [PATCH v6 00/11] implement packed virtqueues Tiwei Bie
2018-09-21 14:06 ` Jens Freimann
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