diff mbox series

[RFC,5/6] virtio-net: support tx netdim

Message ID 20230801082235.21634-6-hengqi@linux.alibaba.com (mailing list archive)
State RFC
Delegated to: Netdev Maintainers
Headers show
Series virtio-net: support dynamic coalescing moderation | expand

Checks

Context Check Description
netdev/tree_selection success Guessing tree name failed - patch did not apply

Commit Message

Heng Qi Aug. 1, 2023, 8:22 a.m. UTC
Similar to rx netdim, this patch supports adaptive tx
coalescing moderation for the virtio-net driver.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
---
 drivers/net/virtio_net.c | 99 ++++++++++++++++++++++++++++++++++------
 1 file changed, 85 insertions(+), 14 deletions(-)
diff mbox series

Patch

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 069e68a52598..d8e66460e37d 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -145,8 +145,14 @@  struct send_queue {
 
 	struct virtnet_sq_stats stats;
 
+	/* The number of tx notifications */
+	u16 calls;
+
 	struct virtnet_interrupt_coalesce intr_coal;
 
+	/* Dynamic Iterrupt Moderation */
+	struct dim dim;
+
 	struct napi_struct napi;
 
 	/* Record whether sq is in reset state. */
@@ -299,6 +305,7 @@  struct virtnet_info {
 
 	/* Is dynamic interrupt moderation enabled? */
 	bool rx_dim_enabled;
+	bool tx_dim_enabled;
 
 	/* Interrupt coalescing settings */
 	struct virtnet_interrupt_coalesce intr_coal_tx;
@@ -435,19 +442,40 @@  static bool virtqueue_napi_complete(struct napi_struct *napi,
 	return false;
 }
 
+static void virtnet_tx_dim_work(struct work_struct *work);
+
+static void virtnet_tx_dim_update(struct virtnet_info *vi, struct send_queue *sq)
+{
+	struct virtnet_sq_stats *stats = &sq->stats;
+	struct dim_sample cur_sample = {};
+
+	u64_stats_update_begin(&sq->stats.syncp);
+	dim_update_sample(sq->calls, stats->packets,
+			  stats->bytes, &cur_sample);
+	u64_stats_update_end(&sq->stats.syncp);
+
+	net_dim(&sq->dim, cur_sample);
+}
+
 static void skb_xmit_done(struct virtqueue *vq)
 {
 	struct virtnet_info *vi = vq->vdev->priv;
-	struct napi_struct *napi = &vi->sq[vq2txq(vq)].napi;
+	struct send_queue *sq = &vi->sq[vq2txq(vq)];
+	struct napi_struct *napi = &sq->napi;
+
+	sq->calls++;
 
 	/* Suppress further interrupts. */
 	virtqueue_disable_cb(vq);
 
-	if (napi->weight)
+	if (napi->weight) {
 		virtqueue_napi_schedule(napi, vq);
-	else
+	} else {
+		if (vi->tx_dim_enabled)
+			virtnet_tx_dim_update(vi, sq);
 		/* We were probably waiting for more output buffers. */
 		netif_wake_subqueue(vi->dev, vq2txq(vq));
+	}
 }
 
 #define MRG_CTX_HEADER_SHIFT 22
@@ -2027,6 +2055,7 @@  static void virtnet_disable_queue_pair(struct virtnet_info *vi, int qp_index)
 	napi_disable(&vi->rq[qp_index].napi);
 	xdp_rxq_info_unreg(&vi->rq[qp_index].xdp_rxq);
 	cancel_work_sync(&vi->rq[qp_index].dim.work);
+	cancel_work_sync(&vi->sq[qp_index].dim.work);
 }
 
 static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
@@ -2046,6 +2075,8 @@  static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
 
 	INIT_WORK(&vi->rq[qp_index].dim.work, virtnet_rx_dim_work);
 	vi->rq[qp_index].dim.mode = DIM_CQ_PERIOD_MODE_START_FROM_EQE;
+	INIT_WORK(&vi->sq[qp_index].dim.work, virtnet_tx_dim_work);
+	vi->sq[qp_index].dim.mode = DIM_CQ_PERIOD_MODE_START_FROM_EQE;
 
 	virtnet_napi_enable(vi->rq[qp_index].vq, &vi->rq[qp_index].napi);
 	virtnet_napi_tx_enable(vi, vi->sq[qp_index].vq, &vi->sq[qp_index].napi);
@@ -2126,6 +2157,9 @@  static int virtnet_poll_tx(struct napi_struct *napi, int budget)
 				__netif_tx_unlock(txq);
 				__napi_schedule(napi);
 			}
+		} else {
+			if (vi->tx_dim_enabled)
+				virtnet_tx_dim_update(vi, sq);
 		}
 	}
 
@@ -3090,20 +3124,33 @@  static int virtnet_get_link_ksettings(struct net_device *dev,
 static int virtnet_send_tx_notf_coal_cmds(struct virtnet_info *vi,
 					  struct ethtool_coalesce *ec)
 {
+	bool tx_ctrl_dim_on = !!ec->use_adaptive_tx_coalesce;
 	struct scatterlist sgs_tx;
 
-	vi->ctrl->coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
-	vi->ctrl->coal_tx.tx_max_packets = cpu_to_le32(ec->tx_max_coalesced_frames);
-	sg_init_one(&sgs_tx, &vi->ctrl->coal_tx, sizeof(vi->ctrl->coal_tx));
-
-	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
-				  VIRTIO_NET_CTRL_NOTF_COAL_TX_SET,
-				  &sgs_tx))
+	if (tx_ctrl_dim_on && (ec->tx_coalesce_usecs != vi->intr_coal_tx.max_usecs ||
+			       ec->tx_max_coalesced_frames != vi->intr_coal_tx.max_packets))
 		return -EINVAL;
 
-	/* Save parameters */
-	vi->intr_coal_tx.max_usecs = ec->tx_coalesce_usecs;
-	vi->intr_coal_tx.max_packets = ec->tx_max_coalesced_frames;
+	if (tx_ctrl_dim_on) {
+		if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL))
+			vi->tx_dim_enabled = true;
+		else
+			return -EOPNOTSUPP;
+	} else if (!tx_ctrl_dim_on) {
+		vi->tx_dim_enabled = false;
+		vi->ctrl->coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
+		vi->ctrl->coal_tx.tx_max_packets = cpu_to_le32(ec->tx_max_coalesced_frames);
+		sg_init_one(&sgs_tx, &vi->ctrl->coal_tx, sizeof(vi->ctrl->coal_tx));
+
+		if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
+					  VIRTIO_NET_CTRL_NOTF_COAL_TX_SET,
+					  &sgs_tx))
+			return -EINVAL;
+
+		/* Save parameters */
+		vi->intr_coal_tx.max_usecs = ec->tx_coalesce_usecs;
+		vi->intr_coal_tx.max_packets = ec->tx_max_coalesced_frames;
+	}
 
 	return 0;
 }
@@ -3194,6 +3241,27 @@  static int virtnet_send_tx_notf_coal_vq_cmd(struct virtnet_info *vi,
 	return 0;
 }
 
+static void virtnet_tx_dim_work(struct work_struct *work)
+{
+	struct dim *dim = container_of(work, struct dim, work);
+	struct send_queue *sq = container_of(dim,
+			struct send_queue, dim);
+	struct virtnet_info *vi = sq->vq->vdev->priv;
+	struct net_device *dev = vi->dev;
+	struct dim_cq_moder update_moder;
+	int qnum = sq - vi->sq, err;
+
+	update_moder = net_dim_get_tx_moderation(dim->mode, dim->profile_ix);
+	err = virtnet_send_tx_notf_coal_vq_cmd(vi, qnum,
+					       update_moder.usec,
+					       update_moder.pkts);
+	if (err)
+		pr_debug("%s: Failed to send dim parameters on txq%d\n",
+				dev->name, (int)(sq - vi->sq));
+
+	dim->state = DIM_START_MEASURE;
+}
+
 static int virtnet_send_rx_notf_coal_vq_cmd(struct virtnet_info *vi,
 					    u16 queue, u32 max_usecs,
 					    u32 max_packets)
@@ -3230,6 +3298,9 @@  static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
 	}
 
 	if (ec->tx_coalesce_usecs || ec->tx_max_coalesced_frames) {
+		if (vi->tx_dim_enabled)
+			return -EBUSY;
+
 		err = virtnet_send_tx_notf_coal_vq_cmd(vi, queue,
 						       ec->tx_coalesce_usecs,
 						       ec->tx_max_coalesced_frames);
@@ -3524,7 +3595,7 @@  static int virtnet_set_rxnfc(struct net_device *dev, struct ethtool_rxnfc *info)
 
 static const struct ethtool_ops virtnet_ethtool_ops = {
 	.supported_coalesce_params = ETHTOOL_COALESCE_MAX_FRAMES |
-		ETHTOOL_COALESCE_USECS | ETHTOOL_COALESCE_USE_ADAPTIVE_RX,
+		ETHTOOL_COALESCE_USECS | ETHTOOL_COALESCE_USE_ADAPTIVE,
 	.get_drvinfo = virtnet_get_drvinfo,
 	.get_link = ethtool_op_get_link,
 	.get_ringparam = virtnet_get_ringparam,