diff mbox series

[v2,03/15] vhost: simplify async IO vectors

Message ID 20211026162904.482987-4-maxime.coquelin@redhat.com (mailing list archive)
State Accepted, archived
Delegated to: Maxime Coquelin
Headers show
Series vhost: clean-up and simplify async implementation | expand

Checks

Context Check Description
ci/checkpatch success coding style OK

Commit Message

Maxime Coquelin Oct. 26, 2021, 4:28 p.m. UTC
IO vectors implementation is unnecessarily complex, mixing
source and destinations vectors in the same array.

This patch declares two arrays, one for the source and one
for the destination. It also get rid off seg_awaits variable
in both packed and split implementation, which is the same
as iovec_idx.

Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
---
 lib/vhost/vhost.h      |  5 +++--
 lib/vhost/virtio_net.c | 28 +++++++++++-----------------
 2 files changed, 14 insertions(+), 19 deletions(-)

Comments

Xia, Chenbo Oct. 29, 2021, 5:37 a.m. UTC | #1
Hi Maxime,

> -----Original Message-----
> From: Maxime Coquelin <maxime.coquelin@redhat.com>
> Sent: Wednesday, October 27, 2021 12:29 AM
> To: dev@dpdk.org; Xia, Chenbo <chenbo.xia@intel.com>; Hu, Jiayu
> <jiayu.hu@intel.com>; Wang, YuanX <yuanx.wang@intel.com>; Ma, WenwuX
> <wenwux.ma@intel.com>; Richardson, Bruce <bruce.richardson@intel.com>;
> Mcnamara, John <john.mcnamara@intel.com>
> Cc: Maxime Coquelin <maxime.coquelin@redhat.com>
> Subject: [PATCH v2 03/15] vhost: simplify async IO vectors
> 
> IO vectors implementation is unnecessarily complex, mixing
> source and destinations vectors in the same array.
> 
> This patch declares two arrays, one for the source and one
> for the destination. It also get rid off seg_awaits variable

Gets rid of

With this fixed:

Reviewed-by: Chenbo Xia <chenbo.xia@intel.com>

> in both packed and split implementation, which is the same
> as iovec_idx.
> 
> Signed-off-by: Maxime Coquelin <maxime.coquelin@redhat.com>
> ---
>  lib/vhost/vhost.h      |  5 +++--
>  lib/vhost/virtio_net.c | 28 +++++++++++-----------------
>  2 files changed, 14 insertions(+), 19 deletions(-)
diff mbox series

Patch

diff --git a/lib/vhost/vhost.h b/lib/vhost/vhost.h
index 8c1c33c852..686f468eff 100644
--- a/lib/vhost/vhost.h
+++ b/lib/vhost/vhost.h
@@ -49,7 +49,7 @@ 
 #define MAX_PKT_BURST 32
 
 #define VHOST_MAX_ASYNC_IT (MAX_PKT_BURST * 2)
-#define VHOST_MAX_ASYNC_VEC (BUF_VECTOR_MAX * 4)
+#define VHOST_MAX_ASYNC_VEC (BUF_VECTOR_MAX * 2)
 
 #define PACKED_DESC_ENQUEUE_USED_FLAG(w)	\
 	((w) ? (VRING_DESC_F_AVAIL | VRING_DESC_F_USED | VRING_DESC_F_WRITE) : \
@@ -133,7 +133,8 @@  struct vhost_async {
 	struct rte_vhost_async_channel_ops ops;
 
 	struct rte_vhost_iov_iter it_pool[VHOST_MAX_ASYNC_IT];
-	struct iovec vec_pool[VHOST_MAX_ASYNC_VEC];
+	struct iovec src_iovec[VHOST_MAX_ASYNC_VEC];
+	struct iovec dst_iovec[VHOST_MAX_ASYNC_VEC];
 
 	/* data transfer status */
 	struct async_inflight_info *pkts_info;
diff --git a/lib/vhost/virtio_net.c b/lib/vhost/virtio_net.c
index d9ac85f829..2a243701c0 100644
--- a/lib/vhost/virtio_net.c
+++ b/lib/vhost/virtio_net.c
@@ -1512,14 +1512,12 @@  virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 
 	struct vhost_async *async = vq->async;
 	struct rte_vhost_iov_iter *it_pool = async->it_pool;
-	struct iovec *vec_pool = async->vec_pool;
 	struct rte_vhost_async_desc tdes[MAX_PKT_BURST];
-	struct iovec *src_iovec = vec_pool;
-	struct iovec *dst_iovec = vec_pool + (VHOST_MAX_ASYNC_VEC >> 1);
+	struct iovec *src_iovec = async->src_iovec;
+	struct iovec *dst_iovec = async->dst_iovec;
 	struct async_inflight_info *pkts_info = async->pkts_info;
 	uint32_t n_pkts = 0, pkt_err = 0;
 	int32_t n_xfer;
-	uint16_t segs_await = 0;
 	uint16_t iovec_idx = 0, it_idx = 0, slot_idx = 0;
 
 	/*
@@ -1562,7 +1560,6 @@  virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 		pkts_info[slot_idx].mbuf = pkts[pkt_idx];
 
 		iovec_idx += it_pool[it_idx].nr_segs;
-		segs_await += it_pool[it_idx].nr_segs;
 		it_idx += 2;
 
 		vq->last_avail_idx += num_buffers;
@@ -1573,8 +1570,7 @@  virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 		 * - unused async iov number is less than max vhost vector
 		 */
 		if (unlikely(pkt_burst_idx >= VHOST_ASYNC_BATCH_THRESHOLD ||
-			((VHOST_MAX_ASYNC_VEC >> 1) - segs_await <
-			BUF_VECTOR_MAX))) {
+			(VHOST_MAX_ASYNC_VEC - iovec_idx < BUF_VECTOR_MAX))) {
 			n_xfer = async->ops.transfer_data(dev->vid,
 					queue_id, tdes, 0, pkt_burst_idx);
 			if (likely(n_xfer >= 0)) {
@@ -1588,7 +1584,6 @@  virtio_dev_rx_async_submit_split(struct virtio_net *dev,
 
 			iovec_idx = 0;
 			it_idx = 0;
-			segs_await = 0;
 
 			if (unlikely(n_pkts < pkt_burst_idx)) {
 				/*
@@ -1745,8 +1740,11 @@  vhost_enqueue_async_packed(struct virtio_net *dev,
 		if (unlikely(++tries > max_tries))
 			return -1;
 
-		if (unlikely(fill_vec_buf_packed(dev, vq, avail_idx, &desc_count, buf_vec, &nr_vec,
-						&buf_id, &len, VHOST_ACCESS_RW) < 0))
+		if (unlikely(fill_vec_buf_packed(dev, vq,
+						avail_idx, &desc_count,
+						buf_vec, &nr_vec,
+						&buf_id, &len,
+						VHOST_ACCESS_RW) < 0))
 			return -1;
 
 		len = RTE_MIN(len, size);
@@ -1832,14 +1830,12 @@  virtio_dev_rx_async_submit_packed(struct virtio_net *dev,
 
 	struct vhost_async *async = vq->async;
 	struct rte_vhost_iov_iter *it_pool = async->it_pool;
-	struct iovec *vec_pool = async->vec_pool;
 	struct rte_vhost_async_desc tdes[MAX_PKT_BURST];
-	struct iovec *src_iovec = vec_pool;
-	struct iovec *dst_iovec = vec_pool + (VHOST_MAX_ASYNC_VEC >> 1);
+	struct iovec *src_iovec = async->src_iovec;
+	struct iovec *dst_iovec = async->dst_iovec;
 	struct async_inflight_info *pkts_info = async->pkts_info;
 	uint32_t n_pkts = 0, pkt_err = 0;
 	uint16_t slot_idx = 0;
-	uint16_t segs_await = 0;
 	uint16_t iovec_idx = 0, it_idx = 0;
 
 	do {
@@ -1861,7 +1857,6 @@  virtio_dev_rx_async_submit_packed(struct virtio_net *dev,
 		pkts_info[slot_idx].nr_buffers = num_buffers;
 		pkts_info[slot_idx].mbuf = pkts[pkt_idx];
 		iovec_idx += it_pool[it_idx].nr_segs;
-		segs_await += it_pool[it_idx].nr_segs;
 		it_idx += 2;
 
 		pkt_idx++;
@@ -1874,7 +1869,7 @@  virtio_dev_rx_async_submit_packed(struct virtio_net *dev,
 		 * - unused async iov number is less than max vhost vector
 		 */
 		if (unlikely(pkt_burst_idx >= VHOST_ASYNC_BATCH_THRESHOLD ||
-			((VHOST_MAX_ASYNC_VEC >> 1) - segs_await < BUF_VECTOR_MAX))) {
+			(VHOST_MAX_ASYNC_VEC - iovec_idx < BUF_VECTOR_MAX))) {
 			n_xfer = async->ops.transfer_data(dev->vid,
 					queue_id, tdes, 0, pkt_burst_idx);
 			if (likely(n_xfer >= 0)) {
@@ -1888,7 +1883,6 @@  virtio_dev_rx_async_submit_packed(struct virtio_net *dev,
 
 			iovec_idx = 0;
 			it_idx = 0;
-			segs_await = 0;
 
 			if (unlikely(n_pkts < pkt_burst_idx)) {
 				/*