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 <hen...@linux.alibaba.com>
---
v5->v5:
- Use spin lock and cancel_work_sync to synchronize
v4->v5:
- Fix possible synchronization issues using cancel_work().
- Reduce if/else nesting levels
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 | 199 ++++++++++++++++++++++++++++++++-------
1 file changed, 167 insertions(+), 32 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 0dd09c4f8d89..882761c64db4 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. */
@@ -308,6 +320,9 @@ 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;
@@ -2004,6 +2019,7 @@ 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);
}
@@ -2144,6 +2160,26 @@ 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 =
@@ -2152,17 +2188,22 @@ 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);
@@ -2233,8 +2274,11 @@ static int virtnet_open(struct net_device *dev)
disable_delayed_refill(vi);
cancel_delayed_work_sync(&vi->refill);
- for (i--; i >= 0; i--)
+ for (i--; i >= 0; i--) {
virtnet_disable_queue_pair(vi, i);
+ cancel_work_sync(&vi->rq[i].dim.work);
+ }
+
return err;
}
@@ -2396,8 +2440,10 @@ 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)
@@ -2652,8 +2698,10 @@ static int virtnet_close(struct net_device *dev)
/* Make sure refill_work doesn't re-enable napi! */
cancel_delayed_work_sync(&vi->refill);
- for (i = 0; i < vi->max_queue_pairs; i++)
+ for (i = 0; i < vi->max_queue_pairs; i++) {
virtnet_disable_queue_pair(vi, i);
+ cancel_work_sync(&vi->rq[i].dim.work);
+ }
return 0;
}
@@ -2905,20 +2953,25 @@ static int virtnet_send_rx_ctrl_coal_vq_cmd(struct
virtnet_info *vi,
return 0;
}
-static int virtnet_send_tx_ctrl_coal_vq_cmd(struct virtnet_info *vi,
- u16 queue, u32 max_usecs,
- u32 max_packets)
+static int virtnet_send_tx_notf_coal_vq_cmds(struct virtnet_info *vi,
+ u16 queue, u32 max_usecs,
+ u32 max_packets)
{
int err;
+ spin_lock(&vi->ctrl_lock);
err = virtnet_send_ctrl_coal_vq_cmd(vi, txq2vq(queue),
max_usecs, max_packets);
- if (err)
+ if (err) {
+ spin_unlock(&vi->ctrl_lock);
return err;
+ }
vi->sq[queue].intr_coal.max_usecs = max_usecs;
vi->sq[queue].intr_coal.max_packets = max_packets;
+ spin_unlock(&vi->ctrl_lock);
+
return 0;
}
@@ -2935,9 +2988,6 @@ static void virtnet_get_ringparam(struct net_device *dev,
ring->tx_pending = virtqueue_get_vring_size(vi->sq[0].vq);
}
-static int virtnet_send_ctrl_coal_vq_cmd(struct virtnet_info *vi,
- u16 vqn, u32 max_usecs, u32
max_packets);
-
static int virtnet_set_ringparam(struct net_device *dev,
struct ethtool_ringparam *ring,
struct kernel_ethtool_ringparam *kernel_ring,
@@ -2979,15 +3029,11 @@ 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.
*/
- spin_lock(&vi->ctrl_lock);
- err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, i,
-
vi->intr_coal_tx.max_usecs,
-
vi->intr_coal_tx.max_packets);
- if (err) {
- spin_unlock(&vi->ctrl_lock);
+ err = virtnet_send_tx_notf_coal_vq_cmds(vi, i,
+
vi->intr_coal_tx.max_usecs,
+
vi->intr_coal_tx.max_packets);
+ if (err)
return err;
- }
- spin_unlock(&vi->ctrl_lock);
}
if (ring->rx_pending != rx_pending) {
@@ -3379,9 +3425,34 @@ 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;
int i;
+ if (rx_ctrl_dim_on && !virtio_has_feature(vi->vdev,
VIRTIO_NET_F_VQ_NOTF_COAL))
+ return -EOPNOTSUPP;
+
+ if (rx_ctrl_dim_on && (ec->rx_coalesce_usecs !=
vi->intr_coal_rx.max_usecs ||
+ ec->rx_max_coalesced_frames !=
vi->intr_coal_rx.max_packets))
+ return -EINVAL;
+
+ if (rx_ctrl_dim_on && !vi->rx_dim_enabled) {
+ vi->rx_dim_enabled = true;
+ for (i = 0; i < vi->max_queue_pairs; i++)
+ vi->rq[i].dim_enabled = true;
+ return 0;
+ }
+
+ if (!rx_ctrl_dim_on && vi->rx_dim_enabled) {
+ vi->rx_dim_enabled = false;
+ for (i = 0; i < vi->max_queue_pairs; i++)
+ vi->rq[i].dim_enabled = false;
+ }
+
+ /* Since the per-queue coalescing params can be set,
+ * we need apply the global new params even if they
+ * are not updated.
+ */
spin_lock(&vi->ctrl_lock);
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);
@@ -3394,7 +3465,6 @@ static int virtnet_send_rx_notf_coal_cmds(struct
virtnet_info *vi,
return -EINVAL;
}
- /* 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++) {
@@ -3423,13 +3493,36 @@ static int virtnet_send_notf_coal_cmds(struct
virtnet_info *vi,
return 0;
}
-static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
- struct ethtool_coalesce *ec,
- u16 queue)
+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;
int err;
spin_lock(&vi->ctrl_lock);
+ max_usecs = vi->rq[queue].intr_coal.max_usecs;
+ max_packets = vi->rq[queue].intr_coal.max_packets;
+ if (rx_ctrl_dim_on && (ec->rx_coalesce_usecs != max_usecs ||
+ ec->rx_max_coalesced_frames != max_packets)) {
+ spin_unlock(&vi->ctrl_lock);
+ return -EINVAL;
+ }
+
+ if (rx_ctrl_dim_on && !cur_rx_dim) {
+ vi->rq[queue].dim_enabled = true;
+ spin_unlock(&vi->ctrl_lock);
+ return 0;
+ }
+
+ if (!rx_ctrl_dim_on && cur_rx_dim)
+ vi->rq[queue].dim_enabled = false;
+
+ /* If no params are updated, userspace ethtool will
+ * reject the modification.
+ */
err = virtnet_send_rx_ctrl_coal_vq_cmd(vi, queue,
ec->rx_coalesce_usecs,
ec->rx_max_coalesced_frames);
@@ -3438,19 +3531,56 @@ static int virtnet_send_notf_coal_vq_cmds(struct
virtnet_info *vi,
return err;
}
- err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, queue,
- ec->tx_coalesce_usecs,
- ec->tx_max_coalesced_frames);
- if (err) {
- spin_unlock(&vi->ctrl_lock);
+ spin_unlock(&vi->ctrl_lock);
+
+ 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_notf_coal_vq_cmds(vi, ec, queue);
+ if (err)
return err;
- }
- spin_unlock(&vi->ctrl_lock);
+ err = virtnet_send_tx_notf_coal_vq_cmds(vi, queue,
+ ec->tx_coalesce_usecs,
+ ec->tx_max_coalesced_frames);
+ if (err)
+ return err;
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);
+ spin_lock(&vi->ctrl_lock);
+ if (update_moder.usec != vi->rq[qnum].intr_coal.max_usecs ||
+ update_moder.pkts != vi->rq[qnum].intr_coal.max_packets) {
+ 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));
+ }
+
+ spin_unlock(&vi->ctrl_lock);
+ 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
@@ -3532,6 +3662,7 @@ 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;
@@ -3589,6 +3720,7 @@ 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;
@@ -3714,7 +3846,7 @@ 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,
@@ -4308,6 +4440,9 @@ static int virtnet_alloc_queues(struct virtnet_info *vi)
virtnet_poll_tx,
napi_tx ? napi_weight : 0);
+ INIT_WORK(&vi->rq[i].dim.work, virtnet_rx_dim_work);
+ vi->rq[i].dim.mode = DIM_CQ_PERIOD_MODE_START_FROM_EQE;
+
sg_init_table(vi->rq[i].sg, ARRAY_SIZE(vi->rq[i].sg));
ewma_pkt_len_init(&vi->rq[i].mrg_avg_pkt_len);
sg_init_table(vi->sq[i].sg, ARRAY_SIZE(vi->sq[i].sg));
--
2.19.1.6.gb485710b
