[PATCHv7 net-next 1/6] net: ibm: emac: use netif_receive_skb_list

From: Rosen Penev
Date: Tue Oct 15 2024 - 16:02:55 EST


Small rx improvement. Would use napi_gro_receive instead but that's a
lot more involved than netif_receive_skb_list because of how the
function is implemented.

Before:

> iperf -c 192.168.1.1
------------------------------------------------------------
Client connecting to 192.168.1.1, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.1.101 port 51556 connected with 192.168.1.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-10.04 sec 559 MBytes 467 Mbits/sec
> iperf -c 192.168.1.1
------------------------------------------------------------
Client connecting to 192.168.1.1, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.1.101 port 48228 connected with 192.168.1.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-10.03 sec 558 MBytes 467 Mbits/sec
> iperf -c 192.168.1.1
------------------------------------------------------------
Client connecting to 192.168.1.1, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.1.101 port 47600 connected with 192.168.1.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-10.04 sec 557 MBytes 466 Mbits/sec
> iperf -c 192.168.1.1
------------------------------------------------------------
Client connecting to 192.168.1.1, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.1.101 port 37252 connected with 192.168.1.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-10.05 sec 559 MBytes 467 Mbits/sec

After:

> iperf -c 192.168.1.1
------------------------------------------------------------
Client connecting to 192.168.1.1, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.1.101 port 40786 connected with 192.168.1.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-10.05 sec 572 MBytes 478 Mbits/sec
> iperf -c 192.168.1.1
------------------------------------------------------------
Client connecting to 192.168.1.1, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.1.101 port 52482 connected with 192.168.1.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-10.04 sec 571 MBytes 477 Mbits/sec
> iperf -c 192.168.1.1
------------------------------------------------------------
Client connecting to 192.168.1.1, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.1.101 port 48370 connected with 192.168.1.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-10.04 sec 572 MBytes 478 Mbits/sec
> iperf -c 192.168.1.1
------------------------------------------------------------
Client connecting to 192.168.1.1, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.1.101 port 46086 connected with 192.168.1.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-10.05 sec 571 MBytes 476 Mbits/sec
> iperf -c 192.168.1.1
------------------------------------------------------------
Client connecting to 192.168.1.1, TCP port 5001
TCP window size: 16.0 KByte (default)
------------------------------------------------------------
[ 1] local 192.168.1.101 port 46062 connected with 192.168.1.1 port 5001
[ ID] Interval Transfer Bandwidth
[ 1] 0.00-10.04 sec 572 MBytes 478 Mbits/sec

Signed-off-by: Rosen Penev <rosenp@xxxxxxxxx>
Reviewed-by: Simon Horman <horms@xxxxxxxxxx>
---
drivers/net/ethernet/ibm/emac/core.c | 6 ++++--
1 file changed, 4 insertions(+), 2 deletions(-)

diff --git a/drivers/net/ethernet/ibm/emac/core.c b/drivers/net/ethernet/ibm/emac/core.c
index dadd987efb6b..0edcb435e62f 100644
--- a/drivers/net/ethernet/ibm/emac/core.c
+++ b/drivers/net/ethernet/ibm/emac/core.c
@@ -1727,6 +1727,7 @@ static inline int emac_rx_sg_append(struct emac_instance *dev, int slot)
/* NAPI poll context */
static int emac_poll_rx(void *param, int budget)
{
+ LIST_HEAD(rx_list);
struct emac_instance *dev = param;
int slot = dev->rx_slot, received = 0;

@@ -1783,8 +1784,7 @@ static int emac_poll_rx(void *param, int budget)
skb->protocol = eth_type_trans(skb, dev->ndev);
emac_rx_csum(dev, skb, ctrl);

- if (unlikely(netif_receive_skb(skb) == NET_RX_DROP))
- ++dev->estats.rx_dropped_stack;
+ list_add_tail(&skb->list, &rx_list);
next:
++dev->stats.rx_packets;
skip:
@@ -1828,6 +1828,8 @@ static int emac_poll_rx(void *param, int budget)
goto next;
}

+ netif_receive_skb_list(&rx_list);
+
if (received) {
DBG2(dev, "rx %d BDs" NL, received);
dev->rx_slot = slot;
--
2.47.0