target/linux/bcm63xx/patches-5.4/440-bcm63xx_enet-batch_process_RX_path.patch

   1 From 1606f78dc82e4f311ca5844a0605a62cd141a072 Mon Sep 17 00:00:00 2001
   2 From: Sieng Piaw Liew <liew.s.piaw@gmail.com>
   3 Date: Mon, 30 Nov 2020 11:07:47 +0800
   4 Subject: [PATCH] bcm63xx: batch process RX path
   5
   6 Use netif_receive_skb_list to batch process skb in RX.
   7 Tested on BCM6328 320 MHz using iperf3 -M 512, increasing performance
   8 by 12.5%.
   9
  10 Before:
  11 [ ID] Interval           Transfer     Bandwidth       Retr
  12 [  4]   0.00-30.00  sec   120 MBytes  33.7 Mbits/sec  277             sender
  13 [  4]   0.00-30.00  sec   120 MBytes  33.5 Mbits/sec                  receiver
  14
  15 After:
  16 [ ID] Interval           Transfer     Bandwidth       Retr
  17 [  4]   0.00-30.00  sec   136 MBytes  37.9 Mbits/sec  203             sender
  18 [  4]   0.00-30.00  sec   135 MBytes  37.7 Mbits/sec                  receiver
  19
  20 Signed-off-by: Sieng Piaw Liew <liew.s.piaw@gmail.com>
  21 ---
  22  drivers/net/ethernet/broadcom/bcm63xx_enet.c | 6 +++++-
  23  1 file changed, 5 insertions(+), 1 deletion(-)
  24
  25 --- a/drivers/net/ethernet/broadcom/bcm63xx_enet.c
  26 +++ b/drivers/net/ethernet/broadcom/bcm63xx_enet.c
  27 @@ -301,10 +301,12 @@ static int bcm_enet_receive_queue(struct
  28         struct bcm_enet_priv *priv;
  29         struct device *kdev;
  30         int processed;
  31 +       struct list_head rx_list;
  32
  33         priv = netdev_priv(dev);
  34         kdev = &priv->pdev->dev;
  35         processed = 0;
  36 +       INIT_LIST_HEAD(&rx_list);
  37
  38         /* don't scan ring further than number of refilled
  39          * descriptor */
  40 @@ -393,10 +395,12 @@ static int bcm_enet_receive_queue(struct
  41                 skb->protocol = eth_type_trans(skb, dev);
  42                 dev->stats.rx_packets++;
  43                 dev->stats.rx_bytes += len;
  44 -               netif_receive_skb(skb);
  45 +               list_add_tail(&skb->list, &rx_list);
  46
  47         } while (--budget > 0);
  48
  49 +       netif_receive_skb_list(&rx_list);
  50 +
  51         if (processed || !priv->rx_desc_count) {
  52                 bcm_enet_refill_rx(dev);
  53