On Tue, Jul 30, 2024 at 05:42:15PM +0200, Greg Kroah-Hartman wrote: > 6.10-stable review patch. If anyone has any objections, please let me know. Wow. It's clearly a feature, not a bugfix. And a risky one, at that. Applies to any stable tree. > ------------------ > > From: Jiri Pirko <jiri@xxxxxxxxxx> > > [ Upstream commit c8bd1f7f3e61fc6c562c806045f3ccd2cc819c01 ] > > Add support for Byte Queue Limits (BQL). > > Tested on qemu emulated virtio_net device with 1, 2 and 4 queues. > Tested with fq_codel and pfifo_fast. Super netperf with 50 threads is > running in background. Netperf TCP_RR results: > > NOBQL FQC 1q: 159.56 159.33 158.50 154.31 agv: 157.925 > NOBQL FQC 2q: 184.64 184.96 174.73 174.15 agv: 179.62 > NOBQL FQC 4q: 994.46 441.96 416.50 499.56 agv: 588.12 > NOBQL PFF 1q: 148.68 148.92 145.95 149.48 agv: 148.2575 > NOBQL PFF 2q: 171.86 171.20 170.42 169.42 agv: 170.725 > NOBQL PFF 4q: 1505.23 1137.23 2488.70 3507.99 agv: 2159.7875 > BQL FQC 1q: 1332.80 1297.97 1351.41 1147.57 agv: 1282.4375 > BQL FQC 2q: 768.30 817.72 864.43 974.40 agv: 856.2125 > BQL FQC 4q: 945.66 942.68 878.51 822.82 agv: 897.4175 > BQL PFF 1q: 149.69 151.49 149.40 147.47 agv: 149.5125 > BQL PFF 2q: 2059.32 798.74 1844.12 381.80 agv: 1270.995 > BQL PFF 4q: 1871.98 4420.02 4916.59 13268.16 agv: 6119.1875 > > Signed-off-by: Jiri Pirko <jiri@xxxxxxxxxx> > Acked-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > Signed-off-by: Michael S. Tsirkin <mst@xxxxxxxxxx> > Link: https://lore.kernel.org/r/20240618144456.1688998-1-jiri@xxxxxxxxxxx > Signed-off-by: Jakub Kicinski <kuba@xxxxxxxxxx> > Stable-dep-of: f8321fa75102 ("virtio_net: Fix napi_skb_cache_put warning") > Signed-off-by: Sasha Levin <sashal@xxxxxxxxxx> > --- > drivers/net/virtio_net.c | 81 ++++++++++++++++++++++++++++------------ > 1 file changed, 57 insertions(+), 24 deletions(-) > > diff --git a/drivers/net/virtio_net.c b/drivers/net/virtio_net.c > index ea10db9a09fa2..b1f8b720733e5 100644 > --- a/drivers/net/virtio_net.c > +++ b/drivers/net/virtio_net.c > @@ -47,7 +47,8 @@ module_param(napi_tx, bool, 0644); > #define VIRTIO_XDP_TX BIT(0) > #define VIRTIO_XDP_REDIR BIT(1) > > -#define VIRTIO_XDP_FLAG BIT(0) > +#define VIRTIO_XDP_FLAG BIT(0) > +#define VIRTIO_ORPHAN_FLAG BIT(1) > > /* RX packet size EWMA. The average packet size is used to determine the packet > * buffer size when refilling RX rings. As the entire RX ring may be refilled > @@ -85,6 +86,8 @@ struct virtnet_stat_desc { > struct virtnet_sq_free_stats { > u64 packets; > u64 bytes; > + u64 napi_packets; > + u64 napi_bytes; > }; > > struct virtnet_sq_stats { > @@ -506,29 +509,50 @@ static struct xdp_frame *ptr_to_xdp(void *ptr) > return (struct xdp_frame *)((unsigned long)ptr & ~VIRTIO_XDP_FLAG); > } > > -static void __free_old_xmit(struct send_queue *sq, bool in_napi, > - struct virtnet_sq_free_stats *stats) > +static bool is_orphan_skb(void *ptr) > +{ > + return (unsigned long)ptr & VIRTIO_ORPHAN_FLAG; > +} > + > +static void *skb_to_ptr(struct sk_buff *skb, bool orphan) > +{ > + return (void *)((unsigned long)skb | (orphan ? VIRTIO_ORPHAN_FLAG : 0)); > +} > + > +static struct sk_buff *ptr_to_skb(void *ptr) > +{ > + return (struct sk_buff *)((unsigned long)ptr & ~VIRTIO_ORPHAN_FLAG); > +} > + > +static void __free_old_xmit(struct send_queue *sq, struct netdev_queue *txq, > + bool in_napi, struct virtnet_sq_free_stats *stats) > { > unsigned int len; > void *ptr; > > while ((ptr = virtqueue_get_buf(sq->vq, &len)) != NULL) { > - ++stats->packets; > - > if (!is_xdp_frame(ptr)) { > - struct sk_buff *skb = ptr; > + struct sk_buff *skb = ptr_to_skb(ptr); > > pr_debug("Sent skb %p\n", skb); > > - stats->bytes += skb->len; > + if (is_orphan_skb(ptr)) { > + stats->packets++; > + stats->bytes += skb->len; > + } else { > + stats->napi_packets++; > + stats->napi_bytes += skb->len; > + } > napi_consume_skb(skb, in_napi); > } else { > struct xdp_frame *frame = ptr_to_xdp(ptr); > > + stats->packets++; > stats->bytes += xdp_get_frame_len(frame); > xdp_return_frame(frame); > } > } > + netdev_tx_completed_queue(txq, stats->napi_packets, stats->napi_bytes); > } > > /* Converting between virtqueue no. and kernel tx/rx queue no. > @@ -955,21 +979,22 @@ static void virtnet_rq_unmap_free_buf(struct virtqueue *vq, void *buf) > virtnet_rq_free_buf(vi, rq, buf); > } > > -static void free_old_xmit(struct send_queue *sq, bool in_napi) > +static void free_old_xmit(struct send_queue *sq, struct netdev_queue *txq, > + bool in_napi) > { > struct virtnet_sq_free_stats stats = {0}; > > - __free_old_xmit(sq, in_napi, &stats); > + __free_old_xmit(sq, txq, in_napi, &stats); > > /* Avoid overhead when no packets have been processed > * happens when called speculatively from start_xmit. > */ > - if (!stats.packets) > + if (!stats.packets && !stats.napi_packets) > return; > > u64_stats_update_begin(&sq->stats.syncp); > - u64_stats_add(&sq->stats.bytes, stats.bytes); > - u64_stats_add(&sq->stats.packets, stats.packets); > + u64_stats_add(&sq->stats.bytes, stats.bytes + stats.napi_bytes); > + u64_stats_add(&sq->stats.packets, stats.packets + stats.napi_packets); > u64_stats_update_end(&sq->stats.syncp); > } > > @@ -1003,7 +1028,9 @@ static void check_sq_full_and_disable(struct virtnet_info *vi, > * early means 16 slots are typically wasted. > */ > if (sq->vq->num_free < 2+MAX_SKB_FRAGS) { > - netif_stop_subqueue(dev, qnum); > + struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum); > + > + netif_tx_stop_queue(txq); > u64_stats_update_begin(&sq->stats.syncp); > u64_stats_inc(&sq->stats.stop); > u64_stats_update_end(&sq->stats.syncp); > @@ -1012,7 +1039,7 @@ static void check_sq_full_and_disable(struct virtnet_info *vi, > virtqueue_napi_schedule(&sq->napi, sq->vq); > } else if (unlikely(!virtqueue_enable_cb_delayed(sq->vq))) { > /* More just got used, free them then recheck. */ > - free_old_xmit(sq, false); > + free_old_xmit(sq, txq, false); > if (sq->vq->num_free >= 2+MAX_SKB_FRAGS) { > netif_start_subqueue(dev, qnum); > u64_stats_update_begin(&sq->stats.syncp); > @@ -1138,7 +1165,8 @@ static int virtnet_xdp_xmit(struct net_device *dev, > } > > /* Free up any pending old buffers before queueing new ones. */ > - __free_old_xmit(sq, false, &stats); > + __free_old_xmit(sq, netdev_get_tx_queue(dev, sq - vi->sq), > + false, &stats); > > for (i = 0; i < n; i++) { > struct xdp_frame *xdpf = frames[i]; > @@ -2331,7 +2359,7 @@ static void virtnet_poll_cleantx(struct receive_queue *rq) > > do { > virtqueue_disable_cb(sq->vq); > - free_old_xmit(sq, true); > + free_old_xmit(sq, txq, true); > } while (unlikely(!virtqueue_enable_cb_delayed(sq->vq))); > > if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) { > @@ -2430,6 +2458,7 @@ static int virtnet_enable_queue_pair(struct virtnet_info *vi, int qp_index) > goto err_xdp_reg_mem_model; > > virtnet_napi_enable(vi->rq[qp_index].vq, &vi->rq[qp_index].napi); > + netdev_tx_reset_queue(netdev_get_tx_queue(vi->dev, qp_index)); > virtnet_napi_tx_enable(vi, vi->sq[qp_index].vq, &vi->sq[qp_index].napi); > > return 0; > @@ -2489,7 +2518,7 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget) > txq = netdev_get_tx_queue(vi->dev, index); > __netif_tx_lock(txq, raw_smp_processor_id()); > virtqueue_disable_cb(sq->vq); > - free_old_xmit(sq, true); > + free_old_xmit(sq, txq, true); > > if (sq->vq->num_free >= 2 + MAX_SKB_FRAGS) { > if (netif_tx_queue_stopped(txq)) { > @@ -2523,7 +2552,7 @@ static int virtnet_poll_tx(struct napi_struct *napi, int budget) > return 0; > } > > -static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) > +static int xmit_skb(struct send_queue *sq, struct sk_buff *skb, bool orphan) > { > struct virtio_net_hdr_mrg_rxbuf *hdr; > const unsigned char *dest = ((struct ethhdr *)skb->data)->h_dest; > @@ -2567,7 +2596,8 @@ static int xmit_skb(struct send_queue *sq, struct sk_buff *skb) > return num_sg; > num_sg++; > } > - return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, skb, GFP_ATOMIC); > + return virtqueue_add_outbuf(sq->vq, sq->sg, num_sg, > + skb_to_ptr(skb, orphan), GFP_ATOMIC); > } > > static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) > @@ -2577,24 +2607,25 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) > struct send_queue *sq = &vi->sq[qnum]; > int err; > struct netdev_queue *txq = netdev_get_tx_queue(dev, qnum); > - bool kick = !netdev_xmit_more(); > + bool xmit_more = netdev_xmit_more(); > bool use_napi = sq->napi.weight; > + bool kick; > > /* Free up any pending old buffers before queueing new ones. */ > do { > if (use_napi) > virtqueue_disable_cb(sq->vq); > > - free_old_xmit(sq, false); > + free_old_xmit(sq, txq, false); > > - } while (use_napi && kick && > + } while (use_napi && !xmit_more && > unlikely(!virtqueue_enable_cb_delayed(sq->vq))); > > /* timestamp packet in software */ > skb_tx_timestamp(skb); > > /* Try to transmit */ > - err = xmit_skb(sq, skb); > + err = xmit_skb(sq, skb, !use_napi); > > /* This should not happen! */ > if (unlikely(err)) { > @@ -2616,7 +2647,9 @@ static netdev_tx_t start_xmit(struct sk_buff *skb, struct net_device *dev) > > check_sq_full_and_disable(vi, dev, sq); > > - if (kick || netif_xmit_stopped(txq)) { > + kick = use_napi ? __netdev_tx_sent_queue(txq, skb->len, xmit_more) : > + !xmit_more || netif_xmit_stopped(txq); > + if (kick) { > if (virtqueue_kick_prepare(sq->vq) && virtqueue_notify(sq->vq)) { > u64_stats_update_begin(&sq->stats.syncp); > u64_stats_inc(&sq->stats.kicks); > -- > 2.43.0 > >
