| Message ID | 20240827210609.12695-8-paul.barker.ct@bp.renesas.com (mailing list archive) |
|---|---|
| State | New |
| Headers | show |
| Series | Backport ravb driver performance improvements | expand |
diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c index cdc3c3be9c4c..fb34491d1fd0 100644 --- a/drivers/net/ethernet/renesas/ravb_main.c +++ b/drivers/net/ethernet/renesas/ravb_main.c @@ -2953,8 +2953,11 @@ static int ravb_probe(struct platform_device *pdev) if (info->nc_queues) netif_napi_add(ndev, &priv->napi[RAVB_NC], ravb_poll); - if (info->coalesce_irqs) + if (info->coalesce_irqs) { netdev_sw_irq_coalesce_default_on(ndev); + if (num_present_cpus() == 1) + dev_set_threaded(ndev, true); + } /* Network device register */ error = register_netdev(ndev);
commit 65c482bc226ab25a7884ee6fd1cc09bb08cbd1be upstream. NAPI Threaded mode (along with the previously enabled SW IRQ Coalescing) is required to improve network stack performance for single core SoCs using the GbEth IP (currently the RZ/G2L SoC family and the RZ/G3S SoC). This patch gives the following improvements during testing with iperf3. * RZ/G2UL: * TCP TX: +32% bandwidth (638Mbps -> 841Mbps) * TXP RX: +8.8% bandwidth (667Mbps -> 726Mbps) * UDP RX: +104% bandwidth (53Mbps -> 108Mbps) * RZ/G3S: * TCP TX: 29% bandwidth (529Mbps -> 681Mbps) * UDP RX: +1290% bandwidth (6.46Mbps -> 90Mbps) * RZ/Five: * UDP RX: Test no longer crashes (0 -> 20 Mbps) This patch gives the following reductions in performance in the same testing: * RZ/G2UL: * UDP TX: -7.5% bandwidth (594Mbps -> 549Mbps) * RZ/G3S: * UDP TX: -5% bandwidth (625Mbps -> 594Mbps) These losses are considered acceptable given the benefits shown above. If UDP TX bandwidth must be maximised for a particular use case, NAPI threaded mode can be disabled at runtime via sysfs writes. 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@bp.renesas.com> Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru> Signed-off-by: Paolo Abeni <pabeni@redhat.com> Reviewed-by: Pavel Machek <pavel@denx.de> Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com> --- drivers/net/ethernet/renesas/ravb_main.c | 5 ++++- 1 file changed, 4 insertions(+), 1 deletion(-)