Software IRQ Coalescing is required to improve network stack performance in the RZ/G2L SoC family and the RZ/G3S SoC, i.e. the SoCs which use the GbEth IP. For the RZ/G2L, network throughput is comparable before and after this change. CPU usage during TCP RX testing dropped by 6.5% and during UDP RX testing dropped by 10%. For the RZ/G2UL, network throughput is generally increased by this change (results obtained with iperf3): * TCP TX: 2.9% more throughput * TCP RX: 1.1% more throughput * UDP TX: similar throughput * UDP RX: 41500% more throughput For the RZ/G3S we see improvements in network throughput similar to the RZ/G2UL. The improvement of UDP RX bandwidth for the single core SoCs (RZ/G2UL & RZ/G3S) is particularly critical. Signed-off-by: Paul Barker <paul.barker.ct@xxxxxxxxxxxxxx> --- drivers/net/ethernet/renesas/ravb.h | 1 + drivers/net/ethernet/renesas/ravb_main.c | 4 ++++ 2 files changed, 5 insertions(+) diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h index 9e9cf0d36d72..da2c09b14389 100644 --- a/drivers/net/ethernet/renesas/ravb.h +++ b/drivers/net/ethernet/renesas/ravb.h @@ -1078,6 +1078,7 @@ struct ravb_hw_info { unsigned nc_queues:1; /* AVB-DMAC has RX and TX NC queues */ unsigned magic_pkt:1; /* E-MAC supports magic packet detection */ unsigned half_duplex:1; /* E-MAC supports half duplex mode */ + unsigned needs_irq_coalesce:1; /* Requires SW IRQ Coalescing to achieve best performance */ }; struct ravb_private { diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index c3a5e4bb61f9..483993ec25ba 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -2684,6 +2684,7 @@ static const struct ravb_hw_info gbeth_hw_info = { .tx_counters = 1, .carrier_counters = 1, .half_duplex = 1, + .needs_irq_coalesce = 1, }; static const struct of_device_id ravb_match_table[] = { @@ -3028,6 +3029,9 @@ static int ravb_probe(struct platform_device *pdev) if (info->nc_queues) netif_napi_add(ndev, &priv->napi[RAVB_NC], info->poll); + if (info->needs_irq_coalesce) + netdev_sw_irq_coalesce_default_on(ndev); + /* Network device register */ error = register_netdev(ndev); if (error) -- 2.39.2