From 6208799553a85875c9f812ba8e4c99d1fc69e8b9 Mon Sep 17 00:00:00 2001 From: Heng Qi Date: Mon, 11 Dec 2023 18:36:07 +0800 Subject: 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 Signed-off-by: David S. Miller --- drivers/net/virtio_net.c | 176 +++++++++++++++++++++++++++++++++++++++++++---- 1 file changed, 162 insertions(+), 14 deletions(-) (limited to 'drivers/net/virtio_net.c') diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c index 69fe09e99b3c..10614e9f7cad 100644 --- a/drivers/net/virtio_net.c +++ b/drivers/net/virtio_net.c @@ -19,6 +19,7 @@ #include #include #include +#include #include #include #include @@ -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 +2157,24 @@ static void virtnet_poll_cleantx(struct receive_queue *rq) } } +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 +2183,22 @@ 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); @@ -2230,8 +2269,11 @@ err_enable_qp: 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; } @@ -2393,8 +2435,10 @@ 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) @@ -2641,8 +2685,10 @@ 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; } @@ -2914,9 +2960,6 @@ 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, @@ -3327,7 +3370,6 @@ static int virtnet_send_tx_notf_coal_cmds(struct virtnet_info *vi, &sgs_tx)) return -EINVAL; - /* Save parameters */ vi->intr_coal_tx.max_usecs = ec->tx_coalesce_usecs; vi->intr_coal_tx.max_packets = ec->tx_max_coalesced_frames; for (i = 0; i < vi->max_queue_pairs; i++) { @@ -3341,9 +3383,34 @@ 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. + */ 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)); @@ -3353,7 +3420,6 @@ static int virtnet_send_rx_notf_coal_cmds(struct virtnet_info *vi, &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; for (i = 0; i < vi->max_queue_pairs; i++) { @@ -3380,18 +3446,52 @@ 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; + 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)) + return -EINVAL; + + if (rx_ctrl_dim_on && !cur_rx_dim) { + vi->rq[queue].dim_enabled = true; + 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); 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_notf_coal_vq_cmds(vi, ec, queue); + if (err) + return err; + err = virtnet_send_tx_ctrl_coal_vq_cmd(vi, queue, ec->tx_coalesce_usecs, ec->tx_max_coalesced_frames); @@ -3401,6 +3501,49 @@ 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 i, qnum, err; + + if (!rtnl_trylock()) + return; + + /* Each rxq's work is queued by "net_dim()->schedule_work()" + * in response to NAPI traffic changes. Note that dim->profile_ix + * for each rxq is updated prior to the queuing action. + * So we only need to traverse and update profiles for all rxqs + * in the work which is holding rtnl_lock. + */ + for (i = 0; i < vi->curr_queue_pairs; i++) { + rq = &vi->rq[i]; + dim = &rq->dim; + qnum = rq - vi->rq; + + if (!rq->dim_enabled) + continue; + + update_moder = net_dim_get_rx_moderation(dim->mode, dim->profile_ix); + if (update_moder.usec != rq->intr_coal.max_usecs || + update_moder.pkts != rq->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, qnum); + dim->state = DIM_START_MEASURE; + } + } + + rtnl_unlock(); +} + static int virtnet_coal_params_supported(struct ethtool_coalesce *ec) { /* usecs coalescing is supported only if VIRTIO_NET_F_NOTF_COAL @@ -3482,6 +3625,7 @@ 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 +3683,7 @@ 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 +3809,7 @@ 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, @@ -4254,6 +4399,9 @@ 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)); -- cgit