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Message-Id: <20230801082235.21634-5-hengqi@linux.alibaba.com>
Date: Tue, 1 Aug 2023 16:22:33 +0800
From: Heng Qi <hengqi@...ux.alibaba.com>
To: "Michael S. Tsirkin" <mst@...hat.com>,
Jason Wang <jasowang@...hat.com>,
netdev@...r.kernel.org,
virtualization@...ts.linux-foundation.org
Cc: "David S. Miller" <davem@...emloft.net>,
Eric Dumazet <edumazet@...gle.com>,
Jakub Kicinski <kuba@...nel.org>,
Paolo Abeni <pabeni@...hat.com>,
Alexei Starovoitov <ast@...nel.org>,
Daniel Borkmann <daniel@...earbox.net>,
Jesper Dangaard Brouer <hawk@...nel.org>,
John Fastabend <john.fastabend@...il.com>,
Xuan Zhuo <xuanzhuo@...ux.alibaba.com>
Subject: [RFC PATCH 4/6] virtio-net: support rx netdim
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@...ux.alibaba.com>
---
drivers/net/virtio_net.c | 97 ++++++++++++++++++++++++++++++++++------
1 file changed, 84 insertions(+), 13 deletions(-)
diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c
index 91b284567c96..069e68a52598 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>
@@ -163,8 +164,14 @@ struct receive_queue {
struct virtnet_rq_stats stats;
+ /* The number of rx notifications */
+ u16 calls;
+
struct virtnet_interrupt_coalesce intr_coal;
+ /* Dynamic Iterrupt Moderation */
+ struct dim dim;
+
/* Chain pages by the private ptr. */
struct page *pages;
@@ -290,6 +297,9 @@ struct virtnet_info {
u8 duplex;
u32 speed;
+ /* Is 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;
@@ -1821,6 +1831,7 @@ 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);
}
@@ -1958,6 +1969,21 @@ 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 virtnet_rq_stats *stats = &rq->stats;
+ struct dim_sample cur_sample = {};
+
+ u64_stats_update_begin(&rq->stats.syncp);
+ dim_update_sample(rq->calls, stats->packets,
+ stats->bytes, &cur_sample);
+ u64_stats_update_end(&rq->stats.syncp);
+
+ net_dim(&rq->dim, cur_sample);
+}
+
static int virtnet_poll(struct napi_struct *napi, int budget)
{
struct receive_queue *rq =
@@ -1966,6 +1992,7 @@ 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);
@@ -1975,8 +2002,11 @@ static int virtnet_poll(struct napi_struct *napi, int budget)
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 && vi->rx_dim_enabled)
+ virtnet_rx_dim_update(vi, rq);
+ }
if (xdp_xmit & VIRTIO_XDP_TX) {
sq = virtnet_xdp_get_sq(vi);
@@ -1996,6 +2026,7 @@ 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)
@@ -2013,6 +2044,9 @@ 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);
@@ -3077,20 +3111,33 @@ 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;
- 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))
+ 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;
- /* Save parameters */
- vi->intr_coal_rx.max_usecs = ec->rx_coalesce_usecs;
- vi->intr_coal_rx.max_packets = ec->rx_max_coalesced_frames;
+ if (rx_ctrl_dim_on) {
+ if (virtio_has_feature(vi->vdev, VIRTIO_NET_F_VQ_NOTF_COAL))
+ vi->rx_dim_enabled = true;
+ else
+ return -EOPNOTSUPP;
+ } else if (!rx_ctrl_dim_on) {
+ vi->rx_dim_enabled = false;
+ 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;
+
+ /* Save parameters */
+ vi->intr_coal_rx.max_usecs = ec->rx_coalesce_usecs;
+ vi->intr_coal_rx.max_packets = ec->rx_max_coalesced_frames;
+ }
return 0;
}
@@ -3172,6 +3219,9 @@ static int virtnet_send_notf_coal_vq_cmds(struct virtnet_info *vi,
int err;
if (ec->rx_coalesce_usecs || ec->rx_max_coalesced_frames) {
+ if (vi->rx_dim_enabled)
+ return -EBUSY;
+
err = virtnet_send_rx_notf_coal_vq_cmd(vi, queue,
ec->rx_coalesce_usecs,
ec->rx_max_coalesced_frames);
@@ -3190,6 +3240,27 @@ 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);
+ err = virtnet_send_rx_notf_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));
+
+ 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
@@ -3453,7 +3524,7 @@ 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
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