-----Original Message-----
From: Yuanhan Liu [mailto:yuanhan.liu@linux.intel.com]
Sent: Friday, August 19, 2016 10:39 AM
To: Wang, Zhihong <redacted>
Cc: dev@dpdk.org; maxime.coquelin@redhat.com
Subject: Re: [PATCH v2 1/6] vhost: rewrite enqueue

On Thu, Aug 18, 2016 at 02:33:06AM -0400, Zhihong Wang wrote:

quoted

This patch implements the vhost logic from scratch into a single function
designed for high performance and better maintainability.

Signed-off-by: Zhihong Wang <redacted>
---
 lib/librte_vhost/vhost_rxtx.c | 212

++++++++++++++++++++++++++++++++++++++++--

quoted

 1 file changed, 205 insertions(+), 7 deletions(-)

diff --git a/lib/librte_vhost/vhost_rxtx.c b/lib/librte_vhost/vhost_rxtx.c
index 08a73fd..8e6d782 100644
--- a/lib/librte_vhost/vhost_rxtx.c
+++ b/lib/librte_vhost/vhost_rxtx.c

@@ -91,7 +91,7 @@ is_valid_virt_queue_idx(uint32_t idx, int is_tx, uint32_t

qp_nb)

quoted

 	return (is_tx ^ (idx & 1)) == 0 && idx < qp_nb * VIRTIO_QNUM;
 }

-static void
+static inline void __attribute__((always_inline))
 virtio_enqueue_offload(struct rte_mbuf *m_buf, struct virtio_net_hdr

*net_hdr)

quoted

 {
 	if (m_buf->ol_flags & PKT_TX_L4_MASK) {

@@ -533,19 +533,217 @@ virtio_dev_merge_rx(struct virtio_net *dev,

uint16_t queue_id,

quoted

 	return pkt_idx;
 }

+static inline uint32_t __attribute__((always_inline))
+loop_check(struct vhost_virtqueue *vq, uint16_t avail_idx, uint32_t pkt_left)
+{
+	if (pkt_left == 0 || avail_idx == vq->last_used_idx)
+		return 1;
+
+	return 0;
+}

Hmmm, I don't see any benifit from making such simple check into a
function.

It's for prefetch code later to be merged into this function.

quoted

+static inline uint32_t __attribute__((always_inline))
+enqueue_packet(struct virtio_net *dev, struct vhost_virtqueue *vq,
+		uint16_t avail_idx, struct rte_mbuf *mbuf,
+		uint32_t is_mrg_rxbuf)
+{
+	struct virtio_net_hdr_mrg_rxbuf *virtio_hdr;
+	struct vring_desc *desc;
+	uint64_t desc_host_write_addr = 0;
+	uint32_t desc_chain_head = 0;
+	uint32_t desc_chain_len = 0;
+	uint32_t desc_current = 0;
+	uint32_t desc_write_offset = 0;
+	uint32_t mbuf_len = 0;
+	uint32_t mbuf_len_left = 0;
+	uint32_t copy_len = 0;

The dequeue function uses var like desc_addr, desc_avail, desc_offset,
mbuf_avail, ..., I see no reason to use something different here. This
breaks the code consistency. Besides that, var name like desc_host_write_addr
looks redundant; desc_addr is much cleaner.

Okay.

	--yliu