diff mbox series

[RFC,net-next,v2,7/7] net: ravb: Use NAPI threaded mode on 1-core CPUs with GbEth IP

Message ID 20240206091909.3191-8-paul.barker.ct@bp.renesas.com
State New
Headers
Series Improve GbEth performance on Renesas RZ/G2L and related SoCs |

Commit Message

Paul Barker Feb. 6, 2024, 9:19 a.m. UTC 
  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).

For the RZ/G2UL, network throughput is greatly increased by this change
(results obtained with iperf3) for all test cases except UDP TX:
  * TCP TX: 30% more throughput
  * TCP RX: 9.8% more throughput
  * UDP TX: 9.7% less throughput
  * UDP RX: 89% 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. NAPI Threaded mode can be disabled at
runtime via sysfs for applications where UDP TX performance is a
priority.

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(-)

Comments

Sergey Shtylyov Feb. 10, 2024, 7 p.m. UTC | #1 
On 2/6/24 12:19 PM, Paul Barker wrote:

> 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).
> 
> For the RZ/G2UL, network throughput is greatly increased by this change
> (results obtained with iperf3) for all test cases except UDP TX:
>   * TCP TX: 30% more throughput
>   * TCP RX: 9.8% more throughput
>   * UDP TX: 9.7% less throughput
>   * UDP RX: 89% 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. NAPI Threaded mode can be disabled at
> runtime via sysfs for applications where UDP TX performance is a
> priority.
> 
> Signed-off-by: Paul Barker <paul.barker.ct@bp.renesas.com>

Reviewed-by: Sergey Shtylyov <s.shtylyov@omp.ru>

[...]

MBR, Sergey
diff mbox series

Patch

diff --git a/drivers/net/ethernet/renesas/ravb_main.c b/drivers/net/ethernet/renesas/ravb_main.c
index 7bb80608f260..522df82524ff 100644
--- a/drivers/net/ethernet/renesas/ravb_main.c
+++ b/drivers/net/ethernet/renesas/ravb_main.c
@@ -2984,8 +2984,11 @@  static int ravb_probe(struct platform_device *pdev)
 	if (info->nc_queues)
 		netif_napi_add(ndev, &priv->napi[RAVB_NC], ravb_poll);
 
-	if (info->needs_irq_coalesce)
+	if (info->needs_irq_coalesce) {
 		netdev_sw_irq_coalesce_default_on(ndev);
+		if (num_present_cpus() == 1)
+			dev_set_threaded(ndev, true);
+	}
 
 	/* Network device register */
 	error = register_netdev(ndev);