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@xxxxxxxxxxxxxxxxx>
---
v2->v3:
- Some minor modifications.
v1->v2:
- Improved the judgment of dim switch conditions.
- Cancel the work when vq reset.
drivers/net/virtio_net.c | 191 ++++++++++++++++++++++++++++++++++-----
1 file changed, 169 insertions(+), 22 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 69fe09e99b3c..bc32d5aae005 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 +3390,55 @@ 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;
+ bool update = false, switch_dim;
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));
-
- 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 {
+ /* Since the per-queue coalescing params can be set,
+ * we need apply the global new params even if they
+ * are not updated.
+ */
+ 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 +3460,54 @@ 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;
+ bool update = false, switch_dim;
+ u32 max_usecs, max_packets;
+ 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 +3520,32 @@ 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 +3627,7 @@ 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 +3685,7 @@ 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 +3811,7 @@ 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
