On Mon, Jul 6, 2026 at 1:39 AM Vladimir Oltean [off-list ref] wrote:

Hi Rosen,

On Sun, Jul 05, 2026 at 08:06:32PM -0700, Rosen Penev wrote:

quoted

Replace netif_receive_skb() with napi_gro_receive() to improve receive
performance for this driver. It has rx checksum support so routing speed
shouldn't suffer.

Tested on a WatchGuard Firebox M300.

iperf3 bidir speed test:

[ ID][Role]   Interval         Transfer      Bitrate        Retr
[  5][TX-C]   0.00-60.01  sec  5.35 GBytes   766 Mbits/sec  184    sender
[  5][TX-C]   0.00-60.02  sec  5.35 GBytes   766 Mbits/sec         receiver
[  7][RX-C]   0.00-60.01  sec  5.50 GBytes   787 Mbits/sec  124    sender
[  7][RX-C]   0.00-60.02  sec  5.49 GBytes   786 Mbits/sec         receiver

After:

[ ID][Role]   Interval         Transfer      Bitrate        Retr
[  5][TX-C]   0.00-60.01  sec  6.49 GBytes   929 Mbits/sec    0    sender
[  5][TX-C]   0.00-60.02  sec  6.49 GBytes   928 Mbits/sec         receiver
[  7][RX-C]   0.00-60.01  sec  6.55 GBytes   938 Mbits/sec    0    sender
[  7][RX-C]   0.00-60.02  sec  6.55 GBytes   937 Mbits/sec         receiver

Assisted-by: Opencode:big-pickle
Signed-off-by: Rosen Penev <redacted>
---
 drivers/net/ethernet/freescale/dpaa/dpaa_eth.c | 5 +----
 1 file changed, 1 insertion(+), 4 deletions(-)

diff --git a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
index ad2d8256eb8d..83191f636ec7 100644
--- a/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c
+++ b/drivers/net/ethernet/freescale/dpaa/dpaa_eth.c

@@ -2824,10 +2824,7 @@ static enum qman_cb_dqrr_result rx_default_dqrr(struct qman_portal *portal,

      skb_len = skb->len;

-     if (unlikely(netif_receive_skb(skb) == NET_RX_DROP)) {
-             percpu_stats->rx_dropped++;
-             return qman_cb_dqrr_consume;
-     }
+     napi_gro_receive(&np->napi, skb);

      percpu_stats->rx_packets++;
      percpu_stats->rx_bytes += skb_len;
--

2.55.0

(thanks to Madalin for pointing out this change to me)

I do not have time this week to test this patch, but in premise, you are
creating exactly the conditions for this bug to occur:
https://github.com/nxp-qoriq/linux/commit/d0ebec2092d6c5fe327513cb66e02d8c2c1a8f87

In sdk_dpaa we already do GRO for TCP flows and it has the problems
pointed out in the above commit. With your change to use GRO for all
capable flows, I currently have no reason to believe that without
similar countermeasures as those taken by sdk_dpaa (napi_gro_receive()
global to the entire QMan portal) the outcome would be different.

Have you tested traffic in mixed scenarios, where flows from multiple
interfaces land on the same CPU?

Just iperf3 --bidir.

Until further evidence comes in:

Maybe netif_receive_skb_list is a better fit here.

pw-bot: cr