[PATCH net-next v2 0/5] virtio-net: support dynamic coalescing moderation

[PATCH net-next v2 0/5] virtio-net: support dynamic coalescing moderation

[Heng Qi]

Now, virtio-net already supports per-queue moderation parameter
setting. Based on this, we use the linux dimlib to support
dynamic coalescing moderation for virtio-net.

Due to some scheduling issues, we only support and test the rx dim.

Some test results:

I. Sockperf UDP
=================================================
1. Env
rxq_0 with affinity to cpu_0.

2. Cmd
client: taskset -c 0 sockperf tp -p 8989 -i $IP -t 10 -m 16B
server: taskset -c 0 sockperf sr -p 8989

3. Result
dim off: 1143277.00 rxpps, throughput 17.844 MBps, cpu is 100%.
dim on:  1124161.00 rxpps, throughput 17.610 MBps, cpu is 83.5%.
=================================================


II. Redis
=================================================
1. Env
There are 8 rxqs, and rxq_i with affinity to cpu_i.

2. Result
When all cpus are 100%, ops/sec of memtier_benchmark client is
dim off:  978437.23
dim on:  1143638.28
=================================================


III. Nginx
=================================================
1. Env
There are 8 rxqs and rxq_i with affinity to cpu_i.

2. Result
When all cpus are 100%, requests/sec of wrk client is
dim off:  877931.67
dim on:  1019160.31
=================================================

IV. Latency of sockperf udp
=================================================
1. Rx cmd
taskset -c 0 sockperf sr -p 8989

2. Tx cmd
taskset -c 0 sockperf pp -i ${ip} -p 8989 -t 10

After running this cmd 5 times and averaging the results,

3. Result
dim off: 17.7735 usec
dim on:  18.0110 usec
=================================================

Changelog:
v1->v2:
- Patch(2/5): a minor fix.
- Patch(4/5):
   - improved the judgment of dim switch conditions.
   - fix safe problem of work thread.
- Patch(5/5): Drop the tx dim implementation.

Heng Qi (5):
  virtio-net: returns whether napi is complete
  virtio-net: separate rx/tx coalescing moderation cmds
  virtio-net: extract virtqueue coalescig cmd for reuse
  virtio-net: support rx netdim
  virtio-net: return -EOPNOTSUPP for adaptive-tx

 drivers/net/virtio_net.c | 331 ++++++++++++++++++++++++++++++++-------
 1 file changed, 274 insertions(+), 57 deletions(-)

-- 
2.19.1.6.gb485710b

[PATCH net-next v2 1/5] virtio-net: returns whether napi is complete

[Heng Qi]

rx netdim needs to count the traffic during a complete napi process,
and start updating and comparing samples to make decisions after
the napi ends. Let virtqueue_napi_complete() return true if napi is done,
otherwise vice versa.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 drivers/net/virtio_net.c | 6 +++++-
 1 file changed, 5 insertions(+), 1 deletion(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index d16f592c2061..0ad2894e6a5e 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -431,7 +431,7 @@ static void virtqueue_napi_schedule(struct napi_struct *napi,
 	}
 }
 
-static void virtqueue_napi_complete(struct napi_struct *napi,
+static bool virtqueue_napi_complete(struct napi_struct *napi,
 				    struct virtqueue *vq, int processed)
 {
 	int opaque;
@@ -440,9 +440,13 @@ static void virtqueue_napi_complete(struct napi_struct *napi,
 	if (napi_complete_done(napi, processed)) {
 		if (unlikely(virtqueue_poll(vq, opaque)))
 			virtqueue_napi_schedule(napi, vq);
+		else
+			return true;
 	} else {
 		virtqueue_disable_cb(vq);
 	}
+
+	return false;
 }
 
 static void skb_xmit_done(struct virtqueue *vq)
-- 
2.19.1.6.gb485710b

[PATCH net-next v2 2/5] virtio-net: separate rx/tx coalescing moderation cmds

[Heng Qi]

This patch separates the rx and tx global coalescing moderation
commands to support netdim switches in subsequent patches.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
---
v1->v2:
- Add 'i' definition.

 drivers/net/virtio_net.c | 31 ++++++++++++++++++++++++++++---
 1 file changed, 28 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0ad2894e6a5e..0285301caf78 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3266,10 +3266,10 @@ static int virtnet_get_link_ksettings(struct net_device *dev,
 	return 0;
 }
 
-static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
-				       struct ethtool_coalesce *ec)
+static int virtnet_send_tx_notf_coal_cmds(struct virtnet_info *vi,
+					  struct ethtool_coalesce *ec)
 {
-	struct scatterlist sgs_tx, sgs_rx;
+	struct scatterlist sgs_tx;
 	int i;
 
 	vi->ctrl->coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
@@ -3289,6 +3289,15 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
 		vi->sq[i].intr_coal.max_packets = ec->tx_max_coalesced_frames;
 	}
 
+	return 0;
+}
+
+static int virtnet_send_rx_notf_coal_cmds(struct virtnet_info *vi,
+					  struct ethtool_coalesce *ec)
+{
+	struct scatterlist sgs_rx;
+	int i;
+
 	vi->ctrl->coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
 	vi->ctrl->coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
 	sg_init_one(&sgs_rx, &vi->ctrl->coal_rx, sizeof(vi->ctrl->coal_rx));
@@ -3309,6 +3318,22 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
 	return 0;
 }
 
+static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
+				       struct ethtool_coalesce *ec)
+{
+	int err;
+
+	err = virtnet_send_tx_notf_coal_cmds(vi, ec);
+	if (err)
+		return err;
+
+	err = virtnet_send_rx_notf_coal_cmds(vi, ec);
+	if (err)
+		return err;
+
+	return 0;
+}
+
 static int virtnet_send_ctrl_coal_vq_cmd(struct virtnet_info *vi,
 					 u16 vqn, u32 max_usecs, u32 max_packets)
 {
-- 
2.19.1.6.gb485710b

Re: [PATCH net-next v2 2/5] virtio-net: separate rx/tx coalescing moderation cmds

[Jason Wang]

On Thu, Nov 2, 2023 at 9:10 PM Heng Qi <hengqi@linux.alibaba.com> wrote:
>
> This patch separates the rx and tx global coalescing moderation
> commands to support netdim switches in subsequent patches.
>
> Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>

Acked-by: Jason Wang <jasowang@redhat.com>

Thanks

> ---
> v1->v2:
> - Add 'i' definition.
>
>  drivers/net/virtio_net.c | 31 ++++++++++++++++++++++++++++---
>  1 file changed, 28 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 0ad2894e6a5e..0285301caf78 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -3266,10 +3266,10 @@ static int virtnet_get_link_ksettings(struct net_device *dev,
>         return 0;
>  }
>
> -static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
> -                                      struct ethtool_coalesce *ec)
> +static int virtnet_send_tx_notf_coal_cmds(struct virtnet_info *vi,
> +                                         struct ethtool_coalesce *ec)
>  {
> -       struct scatterlist sgs_tx, sgs_rx;
> +       struct scatterlist sgs_tx;
>         int i;
>
>         vi->ctrl->coal_tx.tx_usecs = cpu_to_le32(ec->tx_coalesce_usecs);
> @@ -3289,6 +3289,15 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
>                 vi->sq[i].intr_coal.max_packets = ec->tx_max_coalesced_frames;
>         }
>
> +       return 0;
> +}
> +
> +static int virtnet_send_rx_notf_coal_cmds(struct virtnet_info *vi,
> +                                         struct ethtool_coalesce *ec)
> +{
> +       struct scatterlist sgs_rx;
> +       int i;
> +
>         vi->ctrl->coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
>         vi->ctrl->coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
>         sg_init_one(&sgs_rx, &vi->ctrl->coal_rx, sizeof(vi->ctrl->coal_rx));
> @@ -3309,6 +3318,22 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
>         return 0;
>  }
>
> +static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
> +                                      struct ethtool_coalesce *ec)
> +{
> +       int err;
> +
> +       err = virtnet_send_tx_notf_coal_cmds(vi, ec);
> +       if (err)
> +               return err;
> +
> +       err = virtnet_send_rx_notf_coal_cmds(vi, ec);
> +       if (err)
> +               return err;
> +
> +       return 0;
> +}
> +
>  static int virtnet_send_ctrl_coal_vq_cmd(struct virtnet_info *vi,
>                                          u16 vqn, u32 max_usecs, u32 max_packets)
>  {
> --
> 2.19.1.6.gb485710b
>
>

[PATCH net-next v2 3/5] virtio-net: extract virtqueue coalescig cmd for reuse

[Heng Qi]

Extract commands to set virtqueue coalescing parameters for reuse
by ethtool -Q, vq resize and netdim.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
Acked-by: Jason Wang <jasowang@redhat.com>
---
 drivers/net/virtio_net.c | 106 +++++++++++++++++++++++----------------
 1 file changed, 64 insertions(+), 42 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0285301caf78..69fe09e99b3c 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -2849,6 +2849,58 @@ static void virtnet_cpu_notif_remove(struct virtnet_info *vi)
 					    &vi->node_dead);
 }
 
+static int virtnet_send_ctrl_coal_vq_cmd(struct virtnet_info *vi,
+					 u16 vqn, u32 max_usecs, u32 max_packets)
+{
+	struct scatterlist sgs;
+
+	vi->ctrl->coal_vq.vqn = cpu_to_le16(vqn);
+	vi->ctrl->coal_vq.coal.max_usecs = cpu_to_le32(max_usecs);
+	vi->ctrl->coal_vq.coal.max_packets = cpu_to_le32(max_packets);
+	sg_init_one(&sgs, &vi->ctrl->coal_vq, sizeof(vi->ctrl->coal_vq));
+
+	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
+				  VIRTIO_NET_CTRL_NOTF_COAL_VQ_SET,
+				  &sgs))
+		return -EINVAL;
+
+	return 0;
+}
+
+static int virtnet_send_rx_ctrl_coal_vq_cmd(struct virtnet_info *vi,
+					    u16 queue, u32 max_usecs,
+					    u32 max_packets)
+{
+	int err;
+
+	err = virtnet_send_ctrl_coal_vq_cmd(vi, rxq2vq(queue),
+					    max_usecs, max_packets);
+	if (err)
+		return err;
+
+	vi->rq[queue].intr_coal.max_usecs = max_usecs;
+	vi->rq[queue].intr_coal.max_packets = max_packets;
+
+	return 0;
+}
+
+static int virtnet_send_tx_ctrl_coal_vq_cmd(struct virtnet_info *vi,
+					    u16 queue, u32 max_usecs,
+					    u32 max_packets)
+{
+	int err;
+
+	err = virtnet_send_ctrl_coal_vq_cmd(vi, txq2vq(queue),
+					    max_usecs, max_packets);
+	if (err)
+		return err;
+
+	vi->sq[queue].intr_coal.max_usecs = max_usecs;
+	vi->sq[queue].intr_coal.max_packets = max_packets;
+
+	return 0;
+}
+
 static void virtnet_get_ringparam(struct net_device *dev,
 				  struct ethtool_ringparam *ring,
 				  struct kernel_ethtool_ringparam *kernel_ring,
@@ -2906,14 +2958,11 @@ static int virtnet_set_ringparam(struct net_device *dev,
 			 * through the VIRTIO_NET_CTRL_NOTF_COAL_TX_SET command, or, if the driver
 			 * did not set any TX coalescing parameters, to 0.
 			 */
-			err = virtnet_send_ctrl_coal_vq_cmd(vi, txq2vq(i),
-							    vi->intr_coal_tx.max_usecs,
-							    vi->intr_coal_tx.max_packets);
+			err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, i,
+							       vi->intr_coal_tx.max_usecs,
+							       vi->intr_coal_tx.max_packets);
 			if (err)
 				return err;
-
-			vi->sq[i].intr_coal.max_usecs = vi->intr_coal_tx.max_usecs;
-			vi->sq[i].intr_coal.max_packets = vi->intr_coal_tx.max_packets;
 		}
 
 		if (ring->rx_pending != rx_pending) {
@@ -2922,14 +2971,11 @@ static int virtnet_set_ringparam(struct net_device *dev,
 				return err;
 
 			/* The reason is same as the transmit virtqueue reset */
-			err = virtnet_send_ctrl_coal_vq_cmd(vi, rxq2vq(i),
-							    vi->intr_coal_rx.max_usecs,
-							    vi->intr_coal_rx.max_packets);
+			err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, i,
+							       vi->intr_coal_rx.max_usecs,
+							       vi->intr_coal_rx.max_packets);
 			if (err)
 				return err;
-
-			vi->rq[i].intr_coal.max_usecs = vi->intr_coal_rx.max_usecs;
-			vi->rq[i].intr_coal.max_packets = vi->intr_coal_rx.max_packets;
 		}
 	}
 
@@ -3334,48 +3380,24 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
 	return 0;
 }
 
-static int virtnet_send_ctrl_coal_vq_cmd(struct virtnet_info *vi,
-					 u16 vqn, u32 max_usecs, u32 max_packets)
-{
-	struct scatterlist sgs;
-
-	vi->ctrl->coal_vq.vqn = cpu_to_le16(vqn);
-	vi->ctrl->coal_vq.coal.max_usecs = cpu_to_le32(max_usecs);
-	vi->ctrl->coal_vq.coal.max_packets = cpu_to_le32(max_packets);
-	sg_init_one(&sgs, &vi->ctrl->coal_vq, sizeof(vi->ctrl->coal_vq));
-
-	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
-				  VIRTIO_NET_CTRL_NOTF_COAL_VQ_SET,
-				  &sgs))
-		return -EINVAL;
-
-	return 0;
-}
-
 static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
 					  struct ethtool_coalesce *ec,
 					  u16 queue)
 {
 	int err;
 
-	err = virtnet_send_ctrl_coal_vq_cmd(vi, rxq2vq(queue),
-					    ec->rx_coalesce_usecs,
-					    ec->rx_max_coalesced_frames);
+	err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, queue,
+					       ec->rx_coalesce_usecs,
+					       ec->rx_max_coalesced_frames);
 	if (err)
 		return err;
 
-	vi->rq[queue].intr_coal.max_usecs = ec->rx_coalesce_usecs;
-	vi->rq[queue].intr_coal.max_packets = ec->rx_max_coalesced_frames;
-
-	err = virtnet_send_ctrl_coal_vq_cmd(vi, txq2vq(queue),
-					    ec->tx_coalesce_usecs,
-					    ec->tx_max_coalesced_frames);
+	err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, queue,
+					       ec->tx_coalesce_usecs,
+					       ec->tx_max_coalesced_frames);
 	if (err)
 		return err;
 
-	vi->sq[queue].intr_coal.max_usecs = ec->tx_coalesce_usecs;
-	vi->sq[queue].intr_coal.max_packets = ec->tx_max_coalesced_frames;
-
 	return 0;
 }
 
-- 
2.19.1.6.gb485710b

[PATCH net-next v2 4/5] virtio-net: support rx netdim

[Heng Qi]

By comparing the traffic information in the complete napi processes,
let the virtio-net driver automatically adjust the coalescing
moderation parameters of each receive queue.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
---
v1->v2:
- Improved the judgment of dim switch conditions.
- Fix the safe problem of work thread.

 drivers/net/virtio_net.c | 187 ++++++++++++++++++++++++++++++++++-----
 1 file changed, 165 insertions(+), 22 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 69fe09e99b3c..5473aa1ee5cd 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -19,6 +19,7 @@
 #include <linux/average.h>
 #include <linux/filter.h>
 #include <linux/kernel.h>
+#include <linux/dim.h>
 #include <net/route.h>
 #include <net/xdp.h>
 #include <net/net_failover.h>
@@ -172,6 +173,17 @@ struct receive_queue {
 
 	struct virtnet_rq_stats stats;
 
+	/* The number of rx notifications */
+	u16 calls;
+
+	/* Is dynamic interrupt moderation enabled? */
+	bool dim_enabled;
+
+	/* Dynamic Interrupt Moderation */
+	struct dim dim;
+
+	u32 packets_in_napi;
+
 	struct virtnet_interrupt_coalesce intr_coal;
 
 	/* Chain pages by the private ptr. */
@@ -305,6 +317,9 @@ struct virtnet_info {
 	u8 duplex;
 	u32 speed;
 
+	/* Is rx dynamic interrupt moderation enabled? */
+	bool rx_dim_enabled;
+
 	/* Interrupt coalescing settings */
 	struct virtnet_interrupt_coalesce intr_coal_tx;
 	struct virtnet_interrupt_coalesce intr_coal_rx;
@@ -2001,6 +2016,7 @@ static void skb_recv_done(struct virtqueue *rvq)
 	struct virtnet_info *vi = rvq->vdev->priv;
 	struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
 
+	rq->calls++;
 	virtqueue_napi_schedule(&rq->napi, rvq);
 }
 
@@ -2141,6 +2157,26 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
 	}
 }
 
+static void virtnet_rx_dim_work(struct work_struct *work);
+
+static void virtnet_rx_dim_update(struct virtnet_info *vi, struct receive_queue *rq)
+{
+	struct dim_sample cur_sample = {};
+
+	if (!rq->packets_in_napi)
+		return;
+
+	u64_stats_update_begin(&rq->stats.syncp);
+	dim_update_sample(rq->calls,
+			  u64_stats_read(&rq->stats.packets),
+			  u64_stats_read(&rq->stats.bytes),
+			  &cur_sample);
+	u64_stats_update_end(&rq->stats.syncp);
+
+	net_dim(&rq->dim, cur_sample);
+	rq->packets_in_napi = 0;
+}
+
 static int virtnet_poll(struct napi_struct *napi, int budget)
 {
 	struct receive_queue *rq =
@@ -2149,17 +2185,22 @@ static int virtnet_poll(struct napi_struct *napi, int budget)
 	struct send_queue *sq;
 	unsigned int received;
 	unsigned int xdp_xmit = 0;
+	bool napi_complete;
 
 	virtnet_poll_cleantx(rq);
 
 	received = virtnet_receive(rq, budget, &xdp_xmit);
+	rq->packets_in_napi += received;
 
 	if (xdp_xmit & VIRTIO_XDP_REDIR)
 		xdp_do_flush();
 
 	/* Out of packets? */
-	if (received < budget)
-		virtqueue_napi_complete(napi, rq->vq, received);
+	if (received < budget) {
+		napi_complete = virtqueue_napi_complete(napi, rq->vq, received);
+		if (napi_complete && rq->dim_enabled)
+			virtnet_rx_dim_update(vi, rq);
+	}
 
 	if (xdp_xmit & VIRTIO_XDP_TX) {
 		sq = virtnet_xdp_get_sq(vi);
@@ -2179,6 +2220,7 @@ static void virtnet_disable_queue_pair(struct virtnet_info *vi, int qp_index)
 	virtnet_napi_tx_disable(&vi->sq[qp_index].napi);
 	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);
 }
 
 static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
@@ -2196,6 +2238,9 @@ static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
 	if (err < 0)
 		goto err_xdp_reg_mem_model;
 
+	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;
+
 	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);
 
@@ -2393,8 +2438,10 @@ static int virtnet_rx_resize(struct virtnet_info *vi,
 
 	qindex = rq - vi->rq;
 
-	if (running)
+	if (running) {
 		napi_disable(&rq->napi);
+		cancel_work_sync(&rq->dim.work);
+	}
 
 	err = virtqueue_resize(rq->vq, ring_num, virtnet_rq_free_unused_buf);
 	if (err)
@@ -2403,8 +2450,10 @@ static int virtnet_rx_resize(struct virtnet_info *vi,
 	if (!try_fill_recv(vi, rq, GFP_KERNEL))
 		schedule_delayed_work(&vi->refill, 0);
 
-	if (running)
+	if (running) {
+		INIT_WORK(&rq->dim.work, virtnet_rx_dim_work);
 		virtnet_napi_enable(rq->vq, &rq->napi);
+	}
 	return err;
 }
 
@@ -3341,24 +3390,51 @@ static int virtnet_send_tx_notf_coal_cmds(struct virtnet_info *vi,
 static int virtnet_send_rx_notf_coal_cmds(struct virtnet_info *vi,
 					  struct ethtool_coalesce *ec)
 {
+	bool rx_ctrl_dim_on = !!ec->use_adaptive_rx_coalesce;
 	struct scatterlist sgs_rx;
+	bool switch_dim, update;
 	int i;
 
-	vi->ctrl->coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
-	vi->ctrl->coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
-	sg_init_one(&sgs_rx, &vi->ctrl->coal_rx, sizeof(vi->ctrl->coal_rx));
-
-	if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
-				  VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
-				  &sgs_rx))
-		return -EINVAL;
+	switch_dim = rx_ctrl_dim_on != vi->rx_dim_enabled;
+	if (switch_dim) {
+		if (rx_ctrl_dim_on) {
+			if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL)) {
+				vi->rx_dim_enabled = true;
+				for (i = 0; i < vi->max_queue_pairs; i++)
+					vi->rq[i].dim_enabled = true;
+			} else {
+				return -EOPNOTSUPP;
+			}
+		} else {
+			vi->rx_dim_enabled = false;
+			for (i = 0; i < vi->max_queue_pairs; i++)
+				vi->rq[i].dim_enabled = false;
+		}
+	} else {
+		if (ec->rx_coalesce_usecs != vi->intr_coal_rx.max_usecs ||
+		    ec->rx_max_coalesced_frames != vi->intr_coal_rx.max_packets)
+			update = true;
 
-	/* Save parameters */
-	vi->intr_coal_rx.max_usecs = ec->rx_coalesce_usecs;
-	vi->intr_coal_rx.max_packets = ec->rx_max_coalesced_frames;
-	for (i = 0; i < vi->max_queue_pairs; i++) {
-		vi->rq[i].intr_coal.max_usecs = ec->rx_coalesce_usecs;
-		vi->rq[i].intr_coal.max_packets = ec->rx_max_coalesced_frames;
+		if (vi->rx_dim_enabled) {
+			if (update)
+				return -EINVAL;
+		} else {
+			vi->ctrl->coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
+			vi->ctrl->coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
+			sg_init_one(&sgs_rx, &vi->ctrl->coal_rx, sizeof(vi->ctrl->coal_rx));
+
+			if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
+						  VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
+						  &sgs_rx))
+				return -EINVAL;
+
+			vi->intr_coal_rx.max_usecs = ec->rx_coalesce_usecs;
+			vi->intr_coal_rx.max_packets = ec->rx_max_coalesced_frames;
+			for (i = 0; i < vi->max_queue_pairs; i++) {
+				vi->rq[i].intr_coal.max_usecs = ec->rx_coalesce_usecs;
+				vi->rq[i].intr_coal.max_packets = ec->rx_max_coalesced_frames;
+			}
+		}
 	}
 
 	return 0;
@@ -3380,15 +3456,54 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
 	return 0;
 }
 
+static int virtnet_send_rx_notf_coal_vq_cmds(struct virtnet_info *vi,
+					     struct ethtool_coalesce *ec,
+					     u16 queue)
+{
+	bool rx_ctrl_dim_on = !!ec->use_adaptive_rx_coalesce;
+	bool cur_rx_dim = vi->rq[queue].dim_enabled;
+	u32 max_usecs, max_packets;
+	bool switch_dim, update;
+	int err;
+
+	switch_dim = rx_ctrl_dim_on != cur_rx_dim;
+	if (switch_dim) {
+		if (rx_ctrl_dim_on)
+			vi->rq[queue].dim_enabled = true;
+		else
+			vi->rq[queue].dim_enabled = false;
+	} else {
+		max_usecs = vi->rq[queue].intr_coal.max_usecs;
+		max_packets = vi->rq[queue].intr_coal.max_packets;
+		if (ec->rx_coalesce_usecs != max_usecs ||
+		    ec->rx_max_coalesced_frames != max_packets)
+			update = true;
+
+		if (cur_rx_dim) {
+			if (update)
+				return -EINVAL;
+		} else {
+			if (!update)
+				return 0;
+
+			err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, queue,
+							       ec->rx_coalesce_usecs,
+							       ec->rx_max_coalesced_frames);
+			if (err)
+				return err;
+		}
+	}
+
+	return 0;
+}
+
 static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
 					  struct ethtool_coalesce *ec,
 					  u16 queue)
 {
 	int err;
 
-	err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, queue,
-					       ec->rx_coalesce_usecs,
-					       ec->rx_max_coalesced_frames);
+	err = virtnet_send_rx_notf_coal_vq_cmds(vi, ec, queue);
 	if (err)
 		return err;
 
@@ -3401,6 +3516,32 @@ static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
 	return 0;
 }
 
+static void virtnet_rx_dim_work(struct work_struct *work)
+{
+	struct dim *dim = container_of(work, struct dim, work);
+	struct receive_queue *rq = container_of(dim,
+			struct receive_queue, dim);
+	struct virtnet_info *vi = rq->vq->vdev->priv;
+	struct net_device *dev = vi->dev;
+	struct dim_cq_moder update_moder;
+	int qnum = rq - vi->rq, err;
+
+	update_moder = net_dim_get_rx_moderation(dim->mode, dim->profile_ix);
+	if (update_moder.usec != vi->rq[qnum].intr_coal.max_usecs ||
+	    update_moder.pkts != vi->rq[qnum].intr_coal.max_packets) {
+		rtnl_lock();
+		err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, qnum,
+						       update_moder.usec,
+						       update_moder.pkts);
+		if (err)
+			pr_debug("%s: Failed to send dim parameters on rxq%d\n",
+				 dev->name, (int)(rq - vi->rq));
+		rtnl_unlock();
+	}
+
+	dim->state = DIM_START_MEASURE;
+}
+
 static int virtnet_coal_params_supported(struct ethtool_coalesce *ec)
 {
 	/* usecs coalescing is supported only if VIRTIO_NET_F_NOTF_COAL
@@ -3482,6 +3623,7 @@ static int virtnet_get_coalesce(struct net_device *dev,
 		ec->tx_coalesce_usecs = vi->intr_coal_tx.max_usecs;
 		ec->tx_max_coalesced_frames = vi->intr_coal_tx.max_packets;
 		ec->rx_max_coalesced_frames = vi->intr_coal_rx.max_packets;
+		ec->use_adaptive_rx_coalesce = vi->rx_dim_enabled;
 	} else {
 		ec->rx_max_coalesced_frames = 1;
 
@@ -3539,6 +3681,7 @@ static int virtnet_get_per_queue_coalesce(struct net_device *dev,
 		ec->tx_coalesce_usecs = vi->sq[queue].intr_coal.max_usecs;
 		ec->tx_max_coalesced_frames = vi->sq[queue].intr_coal.max_packets;
 		ec->rx_max_coalesced_frames = vi->rq[queue].intr_coal.max_packets;
+		ec->use_adaptive_rx_coalesce = vi->rq[queue].dim_enabled;
 	} else {
 		ec->rx_max_coalesced_frames = 1;
 
@@ -3664,7 +3807,7 @@ 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_USECS | ETHTOOL_COALESCE_USE_ADAPTIVE_RX,
 	.get_drvinfo = virtnet_get_drvinfo,
 	.get_link = ethtool_op_get_link,
 	.get_ringparam = virtnet_get_ringparam,
-- 
2.19.1.6.gb485710b

Re: [PATCH net-next v2 4/5] virtio-net: support rx netdim

[kernel test robot]

Hi Heng,

kernel test robot noticed the following build errors:

[auto build test ERROR on net-next/main]

url:    https://github.com/intel-lab-lkp/linux/commits/Heng-Qi/virtio-net-returns-whether-napi-is-complete/20231103-040818
base:   net-next/main
patch link:    https://lore.kernel.org/r/12c77098b73313eea8fdc88a3d1d20611444827d.1698929590.git.hengqi%40linux.alibaba.com
patch subject: [PATCH net-next v2 4/5] virtio-net: support rx netdim
config: arm-vexpress_defconfig (https://download.01.org/0day-ci/archive/20231106/202311061237.I4bMaa06-lkp@intel.com/config)
compiler: clang version 17.0.0 (https://github.com/llvm/llvm-project.git 4a5ac14ee968ff0ad5d2cc1ffa0299048db4c88a)
reproduce (this is a W=1 build): (https://download.01.org/0day-ci/archive/20231106/202311061237.I4bMaa06-lkp@intel.com/reproduce)

If you fix the issue in a separate patch/commit (i.e. not just a new version of
the same patch/commit), kindly add following tags
| Reported-by: kernel test robot <lkp@intel.com>
| Closes: https://lore.kernel.org/oe-kbuild-all/202311061237.I4bMaa06-lkp@intel.com/

All errors (new ones prefixed by >>):

>> ld.lld: error: undefined symbol: net_dim_get_rx_moderation
   >>> referenced by virtio_net.c:3529 (drivers/net/virtio_net.c:3529)
   >>>               drivers/net/virtio_net.o:(virtnet_rx_dim_work) in archive vmlinux.a
--
>> ld.lld: error: undefined symbol: net_dim
   >>> referenced by virtio_net.c:2176 (drivers/net/virtio_net.c:2176)
   >>>               drivers/net/virtio_net.o:(virtnet_poll) in archive vmlinux.a

-- 
0-DAY CI Kernel Test Service
https://github.com/intel/lkp-tests/wiki

Re: [PATCH net-next v2 4/5] virtio-net: support rx netdim

[Jason Wang]

On Thu, Nov 2, 2023 at 9:10 PM Heng Qi <hengqi@linux.alibaba.com> wrote:
>
> By comparing the traffic information in the complete napi processes,
> let the virtio-net driver automatically adjust the coalescing
> moderation parameters of each receive queue.
>
> Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
> ---
> v1->v2:
> - Improved the judgment of dim switch conditions.
> - Fix the safe problem of work thread.

Nit: it's better to be more concrete here, e.g what kind of "safe
problem" it is.


>
>  drivers/net/virtio_net.c | 187 ++++++++++++++++++++++++++++++++++-----
>  1 file changed, 165 insertions(+), 22 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 69fe09e99b3c..5473aa1ee5cd 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -19,6 +19,7 @@
>  #include <linux/average.h>
>  #include <linux/filter.h>
>  #include <linux/kernel.h>
> +#include <linux/dim.h>
>  #include <net/route.h>
>  #include <net/xdp.h>
>  #include <net/net_failover.h>
> @@ -172,6 +173,17 @@ struct receive_queue {
>
>         struct virtnet_rq_stats stats;
>
> +       /* The number of rx notifications */
> +       u16 calls;
> +
> +       /* Is dynamic interrupt moderation enabled? */
> +       bool dim_enabled;
> +
> +       /* Dynamic Interrupt Moderation */
> +       struct dim dim;
> +
> +       u32 packets_in_napi;
> +
>         struct virtnet_interrupt_coalesce intr_coal;
>
>         /* Chain pages by the private ptr. */
> @@ -305,6 +317,9 @@ struct virtnet_info {
>         u8 duplex;
>         u32 speed;
>
> +       /* Is rx dynamic interrupt moderation enabled? */
> +       bool rx_dim_enabled;
> +
>         /* Interrupt coalescing settings */
>         struct virtnet_interrupt_coalesce intr_coal_tx;
>         struct virtnet_interrupt_coalesce intr_coal_rx;
> @@ -2001,6 +2016,7 @@ static void skb_recv_done(struct virtqueue *rvq)
>         struct virtnet_info *vi = rvq->vdev->priv;
>         struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
>
> +       rq->calls++;
>         virtqueue_napi_schedule(&rq->napi, rvq);
>  }
>
> @@ -2141,6 +2157,26 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
>         }
>  }
>
> +static void virtnet_rx_dim_work(struct work_struct *work);
> +
> +static void virtnet_rx_dim_update(struct virtnet_info *vi, struct receive_queue *rq)
> +{
> +       struct dim_sample cur_sample = {};
> +
> +       if (!rq->packets_in_napi)
> +               return;
> +
> +       u64_stats_update_begin(&rq->stats.syncp);
> +       dim_update_sample(rq->calls,
> +                         u64_stats_read(&rq->stats.packets),
> +                         u64_stats_read(&rq->stats.bytes),
> +                         &cur_sample);
> +       u64_stats_update_end(&rq->stats.syncp);
> +
> +       net_dim(&rq->dim, cur_sample);
> +       rq->packets_in_napi = 0;
> +}
> +
>  static int virtnet_poll(struct napi_struct *napi, int budget)
>  {
>         struct receive_queue *rq =
> @@ -2149,17 +2185,22 @@ static int virtnet_poll(struct napi_struct *napi, int budget)
>         struct send_queue *sq;
>         unsigned int received;
>         unsigned int xdp_xmit = 0;
> +       bool napi_complete;
>
>         virtnet_poll_cleantx(rq);
>
>         received = virtnet_receive(rq, budget, &xdp_xmit);
> +       rq->packets_in_napi += received;
>
>         if (xdp_xmit & VIRTIO_XDP_REDIR)
>                 xdp_do_flush();
>
>         /* Out of packets? */
> -       if (received < budget)
> -               virtqueue_napi_complete(napi, rq->vq, received);
> +       if (received < budget) {
> +               napi_complete = virtqueue_napi_complete(napi, rq->vq, received);
> +               if (napi_complete && rq->dim_enabled)
> +                       virtnet_rx_dim_update(vi, rq);
> +       }
>
>         if (xdp_xmit & VIRTIO_XDP_TX) {
>                 sq = virtnet_xdp_get_sq(vi);
> @@ -2179,6 +2220,7 @@ static void virtnet_disable_queue_pair(struct virtnet_info *vi, int qp_index)
>         virtnet_napi_tx_disable(&vi->sq[qp_index].napi);
>         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);
>  }
>
>  static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
> @@ -2196,6 +2238,9 @@ static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
>         if (err < 0)
>                 goto err_xdp_reg_mem_model;
>
> +       INIT_WORK(&vi->rq[qp_index].dim.work, virtnet_rx_dim_work);

Any reason we need to do the INIT_WORK here but not probe?

> +       vi->rq[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);
>
> @@ -2393,8 +2438,10 @@ static int virtnet_rx_resize(struct virtnet_info *vi,
>
>         qindex = rq - vi->rq;
>
> -       if (running)
> +       if (running) {
>                 napi_disable(&rq->napi);
> +               cancel_work_sync(&rq->dim.work);
> +       }
>
>         err = virtqueue_resize(rq->vq, ring_num, virtnet_rq_free_unused_buf);
>         if (err)
> @@ -2403,8 +2450,10 @@ static int virtnet_rx_resize(struct virtnet_info *vi,
>         if (!try_fill_recv(vi, rq, GFP_KERNEL))
>                 schedule_delayed_work(&vi->refill, 0);
>
> -       if (running)
> +       if (running) {
> +               INIT_WORK(&rq->dim.work, virtnet_rx_dim_work);
>                 virtnet_napi_enable(rq->vq, &rq->napi);
> +       }
>         return err;
>  }
>
> @@ -3341,24 +3390,51 @@ static int virtnet_send_tx_notf_coal_cmds(struct virtnet_info *vi,
>  static int virtnet_send_rx_notf_coal_cmds(struct virtnet_info *vi,
>                                           struct ethtool_coalesce *ec)
>  {
> +       bool rx_ctrl_dim_on = !!ec->use_adaptive_rx_coalesce;
>         struct scatterlist sgs_rx;
> +       bool switch_dim, update;
>         int i;
>
> -       vi->ctrl->coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
> -       vi->ctrl->coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
> -       sg_init_one(&sgs_rx, &vi->ctrl->coal_rx, sizeof(vi->ctrl->coal_rx));
> -
> -       if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
> -                                 VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
> -                                 &sgs_rx))
> -               return -EINVAL;
> +       switch_dim = rx_ctrl_dim_on != vi->rx_dim_enabled;
> +       if (switch_dim) {
> +               if (rx_ctrl_dim_on) {
> +                       if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL)) {
> +                               vi->rx_dim_enabled = true;
> +                               for (i = 0; i < vi->max_queue_pairs; i++)
> +                                       vi->rq[i].dim_enabled = true;
> +                       } else {
> +                               return -EOPNOTSUPP;
> +                       }
> +               } else {
> +                       vi->rx_dim_enabled = false;
> +                       for (i = 0; i < vi->max_queue_pairs; i++)
> +                               vi->rq[i].dim_enabled = false;
> +               }
> +       } else {
> +               if (ec->rx_coalesce_usecs != vi->intr_coal_rx.max_usecs ||
> +                   ec->rx_max_coalesced_frames != vi->intr_coal_rx.max_packets)
> +                       update = true;
>
> -       /* Save parameters */
> -       vi->intr_coal_rx.max_usecs = ec->rx_coalesce_usecs;
> -       vi->intr_coal_rx.max_packets = ec->rx_max_coalesced_frames;
> -       for (i = 0; i < vi->max_queue_pairs; i++) {
> -               vi->rq[i].intr_coal.max_usecs = ec->rx_coalesce_usecs;
> -               vi->rq[i].intr_coal.max_packets = ec->rx_max_coalesced_frames;
> +               if (vi->rx_dim_enabled) {
> +                       if (update)
> +                               return -EINVAL;

update could be used without initialization?

Btw under what condition could we reach here?

Thanks

> +               } else {
> +                       vi->ctrl->coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
> +                       vi->ctrl->coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
> +                       sg_init_one(&sgs_rx, &vi->ctrl->coal_rx, sizeof(vi->ctrl->coal_rx));
> +
> +                       if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
> +                                                 VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
> +                                                 &sgs_rx))
> +                               return -EINVAL;
> +
> +                       vi->intr_coal_rx.max_usecs = ec->rx_coalesce_usecs;
> +                       vi->intr_coal_rx.max_packets = ec->rx_max_coalesced_frames;
> +                       for (i = 0; i < vi->max_queue_pairs; i++) {
> +                               vi->rq[i].intr_coal.max_usecs = ec->rx_coalesce_usecs;
> +                               vi->rq[i].intr_coal.max_packets = ec->rx_max_coalesced_frames;
> +                       }
> +               }
>         }
>
>         return 0;
> @@ -3380,15 +3456,54 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
>         return 0;
>  }
>
> +static int virtnet_send_rx_notf_coal_vq_cmds(struct virtnet_info *vi,
> +                                            struct ethtool_coalesce *ec,
> +                                            u16 queue)
> +{
> +       bool rx_ctrl_dim_on = !!ec->use_adaptive_rx_coalesce;
> +       bool cur_rx_dim = vi->rq[queue].dim_enabled;
> +       u32 max_usecs, max_packets;
> +       bool switch_dim, update;
> +       int err;
> +
> +       switch_dim = rx_ctrl_dim_on != cur_rx_dim;
> +       if (switch_dim) {
> +               if (rx_ctrl_dim_on)
> +                       vi->rq[queue].dim_enabled = true;
> +               else
> +                       vi->rq[queue].dim_enabled = false;
> +       } else {
> +               max_usecs = vi->rq[queue].intr_coal.max_usecs;
> +               max_packets = vi->rq[queue].intr_coal.max_packets;
> +               if (ec->rx_coalesce_usecs != max_usecs ||
> +                   ec->rx_max_coalesced_frames != max_packets)
> +                       update = true;
> +
> +               if (cur_rx_dim) {
> +                       if (update)
> +                               return -EINVAL;
> +               } else {
> +                       if (!update)
> +                               return 0;
> +
> +                       err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, queue,
> +                                                              ec->rx_coalesce_usecs,
> +                                                              ec->rx_max_coalesced_frames);
> +                       if (err)
> +                               return err;
> +               }
> +       }
> +
> +       return 0;
> +}
> +
>  static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
>                                           struct ethtool_coalesce *ec,
>                                           u16 queue)
>  {
>         int err;
>
> -       err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, queue,
> -                                              ec->rx_coalesce_usecs,
> -                                              ec->rx_max_coalesced_frames);
> +       err = virtnet_send_rx_notf_coal_vq_cmds(vi, ec, queue);
>         if (err)
>                 return err;
>
> @@ -3401,6 +3516,32 @@ static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
>         return 0;
>  }
>
> +static void virtnet_rx_dim_work(struct work_struct *work)
> +{
> +       struct dim *dim = container_of(work, struct dim, work);
> +       struct receive_queue *rq = container_of(dim,
> +                       struct receive_queue, dim);
> +       struct virtnet_info *vi = rq->vq->vdev->priv;
> +       struct net_device *dev = vi->dev;
> +       struct dim_cq_moder update_moder;
> +       int qnum = rq - vi->rq, err;
> +
> +       update_moder = net_dim_get_rx_moderation(dim->mode, dim->profile_ix);
> +       if (update_moder.usec != vi->rq[qnum].intr_coal.max_usecs ||
> +           update_moder.pkts != vi->rq[qnum].intr_coal.max_packets) {
> +               rtnl_lock();
> +               err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, qnum,
> +                                                      update_moder.usec,
> +                                                      update_moder.pkts);
> +               if (err)
> +                       pr_debug("%s: Failed to send dim parameters on rxq%d\n",
> +                                dev->name, (int)(rq - vi->rq));
> +               rtnl_unlock();
> +       }
> +
> +       dim->state = DIM_START_MEASURE;
> +}
> +
>  static int virtnet_coal_params_supported(struct ethtool_coalesce *ec)
>  {
>         /* usecs coalescing is supported only if VIRTIO_NET_F_NOTF_COAL
> @@ -3482,6 +3623,7 @@ static int virtnet_get_coalesce(struct net_device *dev,
>                 ec->tx_coalesce_usecs = vi->intr_coal_tx.max_usecs;
>                 ec->tx_max_coalesced_frames = vi->intr_coal_tx.max_packets;
>                 ec->rx_max_coalesced_frames = vi->intr_coal_rx.max_packets;
> +               ec->use_adaptive_rx_coalesce = vi->rx_dim_enabled;
>         } else {
>                 ec->rx_max_coalesced_frames = 1;
>
> @@ -3539,6 +3681,7 @@ static int virtnet_get_per_queue_coalesce(struct net_device *dev,
>                 ec->tx_coalesce_usecs = vi->sq[queue].intr_coal.max_usecs;
>                 ec->tx_max_coalesced_frames = vi->sq[queue].intr_coal.max_packets;
>                 ec->rx_max_coalesced_frames = vi->rq[queue].intr_coal.max_packets;
> +               ec->use_adaptive_rx_coalesce = vi->rq[queue].dim_enabled;
>         } else {
>                 ec->rx_max_coalesced_frames = 1;
>
> @@ -3664,7 +3807,7 @@ 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_USECS | ETHTOOL_COALESCE_USE_ADAPTIVE_RX,
>         .get_drvinfo = virtnet_get_drvinfo,
>         .get_link = ethtool_op_get_link,
>         .get_ringparam = virtnet_get_ringparam,
> --
> 2.19.1.6.gb485710b
>

Re: [PATCH net-next v2 4/5] virtio-net: support rx netdim

[Heng Qi]

在 2023/11/9 下午12:43, Jason Wang 写道:
> On Thu, Nov 2, 2023 at 9:10 PM Heng Qi <hengqi@linux.alibaba.com> wrote:
>> By comparing the traffic information in the complete napi processes,
>> let the virtio-net driver automatically adjust the coalescing
>> moderation parameters of each receive queue.
>>
>> Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
>> ---
>> v1->v2:
>> - Improved the judgment of dim switch conditions.
>> - Fix the safe problem of work thread.
> Nit: it's better to be more concrete here, e.g what kind of "safe
> problem" it is.

Maybe it shouldn't be called a "safe problem" because it won't be 
destructive.
When the specific rxq is reset, the device will respond with errno when 
the work
tries to modifiy parameters for the rxq.

>
>
>>   drivers/net/virtio_net.c | 187 ++++++++++++++++++++++++++++++++++-----
>>   1 file changed, 165 insertions(+), 22 deletions(-)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 69fe09e99b3c..5473aa1ee5cd 100644
>> --- a/drivers/net/virtio_net.c
>> +++ b/drivers/net/virtio_net.c
>> @@ -19,6 +19,7 @@
>>   #include <linux/average.h>
>>   #include <linux/filter.h>
>>   #include <linux/kernel.h>
>> +#include <linux/dim.h>
>>   #include <net/route.h>
>>   #include <net/xdp.h>
>>   #include <net/net_failover.h>
>> @@ -172,6 +173,17 @@ struct receive_queue {
>>
>>          struct virtnet_rq_stats stats;
>>
>> +       /* The number of rx notifications */
>> +       u16 calls;
>> +
>> +       /* Is dynamic interrupt moderation enabled? */
>> +       bool dim_enabled;
>> +
>> +       /* Dynamic Interrupt Moderation */
>> +       struct dim dim;
>> +
>> +       u32 packets_in_napi;
>> +
>>          struct virtnet_interrupt_coalesce intr_coal;
>>
>>          /* Chain pages by the private ptr. */
>> @@ -305,6 +317,9 @@ struct virtnet_info {
>>          u8 duplex;
>>          u32 speed;
>>
>> +       /* Is rx dynamic interrupt moderation enabled? */
>> +       bool rx_dim_enabled;
>> +
>>          /* Interrupt coalescing settings */
>>          struct virtnet_interrupt_coalesce intr_coal_tx;
>>          struct virtnet_interrupt_coalesce intr_coal_rx;
>> @@ -2001,6 +2016,7 @@ static void skb_recv_done(struct virtqueue *rvq)
>>          struct virtnet_info *vi = rvq->vdev->priv;
>>          struct receive_queue *rq = &vi->rq[vq2rxq(rvq)];
>>
>> +       rq->calls++;
>>          virtqueue_napi_schedule(&rq->napi, rvq);
>>   }
>>
>> @@ -2141,6 +2157,26 @@ static void virtnet_poll_cleantx(struct receive_queue *rq)
>>          }
>>   }
>>
>> +static void virtnet_rx_dim_work(struct work_struct *work);
>> +
>> +static void virtnet_rx_dim_update(struct virtnet_info *vi, struct receive_queue *rq)
>> +{
>> +       struct dim_sample cur_sample = {};
>> +
>> +       if (!rq->packets_in_napi)
>> +               return;
>> +
>> +       u64_stats_update_begin(&rq->stats.syncp);
>> +       dim_update_sample(rq->calls,
>> +                         u64_stats_read(&rq->stats.packets),
>> +                         u64_stats_read(&rq->stats.bytes),
>> +                         &cur_sample);
>> +       u64_stats_update_end(&rq->stats.syncp);
>> +
>> +       net_dim(&rq->dim, cur_sample);
>> +       rq->packets_in_napi = 0;
>> +}
>> +
>>   static int virtnet_poll(struct napi_struct *napi, int budget)
>>   {
>>          struct receive_queue *rq =
>> @@ -2149,17 +2185,22 @@ static int virtnet_poll(struct napi_struct *napi, int budget)
>>          struct send_queue *sq;
>>          unsigned int received;
>>          unsigned int xdp_xmit = 0;
>> +       bool napi_complete;
>>
>>          virtnet_poll_cleantx(rq);
>>
>>          received = virtnet_receive(rq, budget, &xdp_xmit);
>> +       rq->packets_in_napi += received;
>>
>>          if (xdp_xmit & VIRTIO_XDP_REDIR)
>>                  xdp_do_flush();
>>
>>          /* Out of packets? */
>> -       if (received < budget)
>> -               virtqueue_napi_complete(napi, rq->vq, received);
>> +       if (received < budget) {
>> +               napi_complete = virtqueue_napi_complete(napi, rq->vq, received);
>> +               if (napi_complete && rq->dim_enabled)
>> +                       virtnet_rx_dim_update(vi, rq);
>> +       }
>>
>>          if (xdp_xmit & VIRTIO_XDP_TX) {
>>                  sq = virtnet_xdp_get_sq(vi);
>> @@ -2179,6 +2220,7 @@ static void virtnet_disable_queue_pair(struct virtnet_info *vi, int qp_index)
>>          virtnet_napi_tx_disable(&vi->sq[qp_index].napi);
>>          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);
>>   }
>>
>>   static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
>> @@ -2196,6 +2238,9 @@ static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index)
>>          if (err < 0)
>>                  goto err_xdp_reg_mem_model;
>>
>> +       INIT_WORK(&vi->rq[qp_index].dim.work, virtnet_rx_dim_work);
> Any reason we need to do the INIT_WORK here but not probe?

This can initialize the work when the device status changes (open, restore).
At this time, rxq is ready and once it's napi is enabled, the work can 
start working.

>
>> +       vi->rq[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);
>>
>> @@ -2393,8 +2438,10 @@ static int virtnet_rx_resize(struct virtnet_info *vi,
>>
>>          qindex = rq - vi->rq;
>>
>> -       if (running)
>> +       if (running) {
>>                  napi_disable(&rq->napi);
>> +               cancel_work_sync(&rq->dim.work);
>> +       }
>>
>>          err = virtqueue_resize(rq->vq, ring_num, virtnet_rq_free_unused_buf);
>>          if (err)
>> @@ -2403,8 +2450,10 @@ static int virtnet_rx_resize(struct virtnet_info *vi,
>>          if (!try_fill_recv(vi, rq, GFP_KERNEL))
>>                  schedule_delayed_work(&vi->refill, 0);
>>
>> -       if (running)
>> +       if (running) {
>> +               INIT_WORK(&rq->dim.work, virtnet_rx_dim_work);
>>                  virtnet_napi_enable(rq->vq, &rq->napi);
>> +       }
>>          return err;
>>   }
>>
>> @@ -3341,24 +3390,51 @@ static int virtnet_send_tx_notf_coal_cmds(struct virtnet_info *vi,
>>   static int virtnet_send_rx_notf_coal_cmds(struct virtnet_info *vi,
>>                                            struct ethtool_coalesce *ec)
>>   {
>> +       bool rx_ctrl_dim_on = !!ec->use_adaptive_rx_coalesce;
>>          struct scatterlist sgs_rx;
>> +       bool switch_dim, update;
>>          int i;
>>
>> -       vi->ctrl->coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
>> -       vi->ctrl->coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
>> -       sg_init_one(&sgs_rx, &vi->ctrl->coal_rx, sizeof(vi->ctrl->coal_rx));
>> -
>> -       if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
>> -                                 VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
>> -                                 &sgs_rx))
>> -               return -EINVAL;
>> +       switch_dim = rx_ctrl_dim_on != vi->rx_dim_enabled;
>> +       if (switch_dim) {
>> +               if (rx_ctrl_dim_on) {
>> +                       if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL)) {
>> +                               vi->rx_dim_enabled = true;
>> +                               for (i = 0; i < vi->max_queue_pairs; i++)
>> +                                       vi->rq[i].dim_enabled = true;
>> +                       } else {
>> +                               return -EOPNOTSUPP;
>> +                       }
>> +               } else {
>> +                       vi->rx_dim_enabled = false;
>> +                       for (i = 0; i < vi->max_queue_pairs; i++)
>> +                               vi->rq[i].dim_enabled = false;
>> +               }
>> +       } else {
>> +               if (ec->rx_coalesce_usecs != vi->intr_coal_rx.max_usecs ||
>> +                   ec->rx_max_coalesced_frames != vi->intr_coal_rx.max_packets)
>> +                       update = true;
>>
>> -       /* Save parameters */
>> -       vi->intr_coal_rx.max_usecs = ec->rx_coalesce_usecs;
>> -       vi->intr_coal_rx.max_packets = ec->rx_max_coalesced_frames;
>> -       for (i = 0; i < vi->max_queue_pairs; i++) {
>> -               vi->rq[i].intr_coal.max_usecs = ec->rx_coalesce_usecs;
>> -               vi->rq[i].intr_coal.max_packets = ec->rx_max_coalesced_frames;
>> +               if (vi->rx_dim_enabled) {
>> +                       if (update)
>> +                               return -EINVAL;
> update could be used without initialization?

It defaults to false, but I will initialize it explicitly in the next 
version.

>
> Btw under what condition could we reach here?

If the current dim status is on, and this condition is triggered when 
the user
tries to modify parameters.

Thanks!

>
> Thanks
>
>> +               } else {
>> +                       vi->ctrl->coal_rx.rx_usecs = cpu_to_le32(ec->rx_coalesce_usecs);
>> +                       vi->ctrl->coal_rx.rx_max_packets = cpu_to_le32(ec->rx_max_coalesced_frames);
>> +                       sg_init_one(&sgs_rx, &vi->ctrl->coal_rx, sizeof(vi->ctrl->coal_rx));
>> +
>> +                       if (!virtnet_send_command(vi, VIRTIO_NET_CTRL_NOTF_COAL,
>> +                                                 VIRTIO_NET_CTRL_NOTF_COAL_RX_SET,
>> +                                                 &sgs_rx))
>> +                               return -EINVAL;
>> +
>> +                       vi->intr_coal_rx.max_usecs = ec->rx_coalesce_usecs;
>> +                       vi->intr_coal_rx.max_packets = ec->rx_max_coalesced_frames;
>> +                       for (i = 0; i < vi->max_queue_pairs; i++) {
>> +                               vi->rq[i].intr_coal.max_usecs = ec->rx_coalesce_usecs;
>> +                               vi->rq[i].intr_coal.max_packets = ec->rx_max_coalesced_frames;
>> +                       }
>> +               }
>>          }
>>
>>          return 0;
>> @@ -3380,15 +3456,54 @@ static int virtnet_send_notf_coal_cmds(struct virtnet_info *vi,
>>          return 0;
>>   }
>>
>> +static int virtnet_send_rx_notf_coal_vq_cmds(struct virtnet_info *vi,
>> +                                            struct ethtool_coalesce *ec,
>> +                                            u16 queue)
>> +{
>> +       bool rx_ctrl_dim_on = !!ec->use_adaptive_rx_coalesce;
>> +       bool cur_rx_dim = vi->rq[queue].dim_enabled;
>> +       u32 max_usecs, max_packets;
>> +       bool switch_dim, update;
>> +       int err;
>> +
>> +       switch_dim = rx_ctrl_dim_on != cur_rx_dim;
>> +       if (switch_dim) {
>> +               if (rx_ctrl_dim_on)
>> +                       vi->rq[queue].dim_enabled = true;
>> +               else
>> +                       vi->rq[queue].dim_enabled = false;
>> +       } else {
>> +               max_usecs = vi->rq[queue].intr_coal.max_usecs;
>> +               max_packets = vi->rq[queue].intr_coal.max_packets;
>> +               if (ec->rx_coalesce_usecs != max_usecs ||
>> +                   ec->rx_max_coalesced_frames != max_packets)
>> +                       update = true;
>> +
>> +               if (cur_rx_dim) {
>> +                       if (update)
>> +                               return -EINVAL;
>> +               } else {
>> +                       if (!update)
>> +                               return 0;
>> +
>> +                       err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, queue,
>> +                                                              ec->rx_coalesce_usecs,
>> +                                                              ec->rx_max_coalesced_frames);
>> +                       if (err)
>> +                               return err;
>> +               }
>> +       }
>> +
>> +       return 0;
>> +}
>> +
>>   static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
>>                                            struct ethtool_coalesce *ec,
>>                                            u16 queue)
>>   {
>>          int err;
>>
>> -       err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, queue,
>> -                                              ec->rx_coalesce_usecs,
>> -                                              ec->rx_max_coalesced_frames);
>> +       err = virtnet_send_rx_notf_coal_vq_cmds(vi, ec, queue);
>>          if (err)
>>                  return err;
>>
>> @@ -3401,6 +3516,32 @@ static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
>>          return 0;
>>   }
>>
>> +static void virtnet_rx_dim_work(struct work_struct *work)
>> +{
>> +       struct dim *dim = container_of(work, struct dim, work);
>> +       struct receive_queue *rq = container_of(dim,
>> +                       struct receive_queue, dim);
>> +       struct virtnet_info *vi = rq->vq->vdev->priv;
>> +       struct net_device *dev = vi->dev;
>> +       struct dim_cq_moder update_moder;
>> +       int qnum = rq - vi->rq, err;
>> +
>> +       update_moder = net_dim_get_rx_moderation(dim->mode, dim->profile_ix);
>> +       if (update_moder.usec != vi->rq[qnum].intr_coal.max_usecs ||
>> +           update_moder.pkts != vi->rq[qnum].intr_coal.max_packets) {
>> +               rtnl_lock();
>> +               err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, qnum,
>> +                                                      update_moder.usec,
>> +                                                      update_moder.pkts);
>> +               if (err)
>> +                       pr_debug("%s: Failed to send dim parameters on rxq%d\n",
>> +                                dev->name, (int)(rq - vi->rq));
>> +               rtnl_unlock();
>> +       }
>> +
>> +       dim->state = DIM_START_MEASURE;
>> +}
>> +
>>   static int virtnet_coal_params_supported(struct ethtool_coalesce *ec)
>>   {
>>          /* usecs coalescing is supported only if VIRTIO_NET_F_NOTF_COAL
>> @@ -3482,6 +3623,7 @@ static int virtnet_get_coalesce(struct net_device *dev,
>>                  ec->tx_coalesce_usecs = vi->intr_coal_tx.max_usecs;
>>                  ec->tx_max_coalesced_frames = vi->intr_coal_tx.max_packets;
>>                  ec->rx_max_coalesced_frames = vi->intr_coal_rx.max_packets;
>> +               ec->use_adaptive_rx_coalesce = vi->rx_dim_enabled;
>>          } else {
>>                  ec->rx_max_coalesced_frames = 1;
>>
>> @@ -3539,6 +3681,7 @@ static int virtnet_get_per_queue_coalesce(struct net_device *dev,
>>                  ec->tx_coalesce_usecs = vi->sq[queue].intr_coal.max_usecs;
>>                  ec->tx_max_coalesced_frames = vi->sq[queue].intr_coal.max_packets;
>>                  ec->rx_max_coalesced_frames = vi->rq[queue].intr_coal.max_packets;
>> +               ec->use_adaptive_rx_coalesce = vi->rq[queue].dim_enabled;
>>          } else {
>>                  ec->rx_max_coalesced_frames = 1;
>>
>> @@ -3664,7 +3807,7 @@ 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_USECS | ETHTOOL_COALESCE_USE_ADAPTIVE_RX,
>>          .get_drvinfo = virtnet_get_drvinfo,
>>          .get_link = ethtool_op_get_link,
>>          .get_ringparam = virtnet_get_ringparam,
>> --
>> 2.19.1.6.gb485710b
>>

[PATCH net-next v2 5/5] virtio-net: return -EOPNOTSUPP for adaptive-tx

[Heng Qi]

We do not currently support tx dim, so respond to -EOPNOTSUPP.

Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
---
v1->v2:
- Use -EOPNOTSUPP instead of specific implementation.

 drivers/net/virtio_net.c | 29 ++++++++++++++++++++++++++---
 1 file changed, 26 insertions(+), 3 deletions(-)

diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 5473aa1ee5cd..03edeadd0725 100644
--- a/drivers/net/virtio_net.c
+++ b/drivers/net/virtio_net.c
@@ -3364,9 +3364,15 @@ 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;
 	int i;
 
+	if (tx_ctrl_dim_on) {
+		pr_debug("Failed to enable adaptive-tx, which is not supported\n");
+		return -EOPNOTSUPP;
+	}
+
 	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));
@@ -3497,6 +3503,25 @@ static int virtnet_send_rx_notf_coal_vq_cmds(struct virtnet_info *vi,
 	return 0;
 }
 
+static int virtnet_send_tx_notf_coal_vq_cmds(struct virtnet_info *vi,
+					     struct ethtool_coalesce *ec,
+					     u16 queue)
+{
+	bool tx_ctrl_dim_on = !!ec->use_adaptive_tx_coalesce;
+	int err;
+
+	if (tx_ctrl_dim_on) {
+		pr_debug("Enabling adaptive-tx for txq%d is not supported\n", queue);
+		return -EOPNOTSUPP;
+	}
+
+	err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, queue,
+					       ec->tx_coalesce_usecs,
+					       ec->tx_max_coalesced_frames);
+
+	return err;
+}
+
 static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
 					  struct ethtool_coalesce *ec,
 					  u16 queue)
@@ -3507,9 +3532,7 @@ static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
 	if (err)
 		return err;
 
-	err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, queue,
-					       ec->tx_coalesce_usecs,
-					       ec->tx_max_coalesced_frames);
+	err = virtnet_send_tx_notf_coal_vq_cmds(vi, ec, queue);
 	if (err)
 		return err;
 
-- 
2.19.1.6.gb485710b

Re: [PATCH net-next v2 5/5] virtio-net: return -EOPNOTSUPP for adaptive-tx

[Jason Wang]

On Thu, Nov 2, 2023 at 9:10 PM Heng Qi <hengqi@linux.alibaba.com> wrote:
>
> We do not currently support tx dim, so respond to -EOPNOTSUPP.
>
> Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
> ---
> v1->v2:
> - Use -EOPNOTSUPP instead of specific implementation.
>
>  drivers/net/virtio_net.c | 29 ++++++++++++++++++++++++++---
>  1 file changed, 26 insertions(+), 3 deletions(-)
>
> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
> index 5473aa1ee5cd..03edeadd0725 100644
> --- a/drivers/net/virtio_net.c
> +++ b/drivers/net/virtio_net.c
> @@ -3364,9 +3364,15 @@ 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;
>         int i;
>
> +       if (tx_ctrl_dim_on) {
> +               pr_debug("Failed to enable adaptive-tx, which is not supported\n");
> +               return -EOPNOTSUPP;
> +       }

When can we hit this?

Thanks

> +
>         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));
> @@ -3497,6 +3503,25 @@ static int virtnet_send_rx_notf_coal_vq_cmds(struct virtnet_info *vi,
>         return 0;
>  }
>
> +static int virtnet_send_tx_notf_coal_vq_cmds(struct virtnet_info *vi,
> +                                            struct ethtool_coalesce *ec,
> +                                            u16 queue)
> +{
> +       bool tx_ctrl_dim_on = !!ec->use_adaptive_tx_coalesce;
> +       int err;
> +
> +       if (tx_ctrl_dim_on) {
> +               pr_debug("Enabling adaptive-tx for txq%d is not supported\n", queue);
> +               return -EOPNOTSUPP;
> +       }
> +
> +       err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, queue,
> +                                              ec->tx_coalesce_usecs,
> +                                              ec->tx_max_coalesced_frames);
> +
> +       return err;
> +}
> +
>  static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
>                                           struct ethtool_coalesce *ec,
>                                           u16 queue)
> @@ -3507,9 +3532,7 @@ static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
>         if (err)
>                 return err;
>
> -       err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, queue,
> -                                              ec->tx_coalesce_usecs,
> -                                              ec->tx_max_coalesced_frames);
> +       err = virtnet_send_tx_notf_coal_vq_cmds(vi, ec, queue);
>         if (err)
>                 return err;
>
> --
> 2.19.1.6.gb485710b
>

Re: [PATCH net-next v2 5/5] virtio-net: return -EOPNOTSUPP for adaptive-tx

[Heng Qi]

在 2023/11/9 下午12:45, Jason Wang 写道:
> On Thu, Nov 2, 2023 at 9:10 PM Heng Qi <hengqi@linux.alibaba.com> wrote:
>> We do not currently support tx dim, so respond to -EOPNOTSUPP.
>>
>> Signed-off-by: Heng Qi <hengqi@linux.alibaba.com>
>> ---
>> v1->v2:
>> - Use -EOPNOTSUPP instead of specific implementation.
>>
>>   drivers/net/virtio_net.c | 29 ++++++++++++++++++++++++++---
>>   1 file changed, 26 insertions(+), 3 deletions(-)
>>
>> diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
>> index 5473aa1ee5cd..03edeadd0725 100644
>> --- a/drivers/net/virtio_net.c
>> +++ b/drivers/net/virtio_net.c
>> @@ -3364,9 +3364,15 @@ 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;
>>          int i;
>>
>> +       if (tx_ctrl_dim_on) {
>> +               pr_debug("Failed to enable adaptive-tx, which is not supported\n");
>> +               return -EOPNOTSUPP;
>> +       }
> When can we hit this?

When user tries to enable tx dim using following cmd:
'ethtool -C eth0 adaptive-tx on'

Thanks!

>
> Thanks
>
>> +
>>          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));
>> @@ -3497,6 +3503,25 @@ static int virtnet_send_rx_notf_coal_vq_cmds(struct virtnet_info *vi,
>>          return 0;
>>   }
>>
>> +static int virtnet_send_tx_notf_coal_vq_cmds(struct virtnet_info *vi,
>> +                                            struct ethtool_coalesce *ec,
>> +                                            u16 queue)
>> +{
>> +       bool tx_ctrl_dim_on = !!ec->use_adaptive_tx_coalesce;
>> +       int err;
>> +
>> +       if (tx_ctrl_dim_on) {
>> +               pr_debug("Enabling adaptive-tx for txq%d is not supported\n", queue);
>> +               return -EOPNOTSUPP;
>> +       }
>> +
>> +       err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, queue,
>> +                                              ec->tx_coalesce_usecs,
>> +                                              ec->tx_max_coalesced_frames);
>> +
>> +       return err;
>> +}
>> +
>>   static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
>>                                            struct ethtool_coalesce *ec,
>>                                            u16 queue)
>> @@ -3507,9 +3532,7 @@ static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
>>          if (err)
>>                  return err;
>>
>> -       err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, queue,
>> -                                              ec->tx_coalesce_usecs,
>> -                                              ec->tx_max_coalesced_frames);
>> +       err = virtnet_send_tx_notf_coal_vq_cmds(vi, ec, queue);
>>          if (err)
>>                  return err;
>>
>> --
>> 2.19.1.6.gb485710b
>>