Received-SPF: pass (google.com: domain of linux-kernel+bounces-151934-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Subject: Re: [net-next RFC v3 5/7] net: ravb: Enable SW IRQ Coalescing for
 GbEth
To: Paul Barker <paul.barker.ct@bp.renesas.com>, "David S. Miller"
	<davem@davemloft.net>, Eric Dumazet <edumazet@google.com>, Jakub Kicinski
	<kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
CC: =?UTF-8?Q?Niklas_S=c3=b6derlund?= <niklas.soderlund+renesas@ragnatech.se>,
	Geert Uytterhoeven <geert+renesas@glider.be>, <netdev@vger.kernel.org>,
	<linux-renesas-soc@vger.kernel.org>, <linux-kernel@vger.kernel.org>
References: <20240415094804.8016-1-paul.barker.ct@bp.renesas.com>
 <20240415094804.8016-6-paul.barker.ct@bp.renesas.com>
From: Sergey Shtylyov <s.shtylyov@omp.ru>
Organization: Open Mobile Platform
Message-ID: <fb0912c7-46d1-e5eb-5329-ddfe16495b8a@omp.ru>
Date: Fri, 19 Apr 2024 23:26:05 +0300
User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101
 Thunderbird/78.10.1
Precedence: bulk
MIME-Version: 1.0
In-Reply-To: <20240415094804.8016-6-paul.barker.ct@bp.renesas.com>
Content-Type: text/plain; charset="utf-8"
Content-Language: en-US
Content-Transfer-Encoding: 7bit
X-KSE-Attachment-Filter-Triggered-Filters: Clean
X-KSE-BulkMessagesFiltering-Scan-Result: InTheLimit

On 4/15/24 12:48 PM, Paul Barker wrote:

> 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.
> 
> This patch gives the following improvements during testing with iperf3:
> 
>   * RZ/G2L:
>     * TCP RX: same bandwidth with -6% CPU load (76% -> 71%)
>     * UDP RX: same bandwidth with -10% CPU load (99% -> 89%)
> 
>   * RZ/G2UL:
>     * UDP RX: +4200% bandwidth (1.23Mbps -> 53Mbps)
> 
>   * RZ/G3S:
>     * UDP RX: +425% bandwidth (1.23Mbps -> 6.46Mbps)
> 
> 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>

[...]

> diff --git a/drivers/net/ethernet/renesas/ravb.h b/drivers/net/ethernet/renesas/ravb.h
> index 71de2a7aa27c..9c6392ade2f1 100644
> --- a/drivers/net/ethernet/renesas/ravb.h
> +++ b/drivers/net/ethernet/renesas/ravb.h
> @@ -1054,6 +1054,7 @@ struct ravb_hw_info {
>  	u32 rx_max_desc_use;
>  	u32 rx_desc_size;
>  	unsigned aligned_tx: 1;
> +	unsigned needs_irq_coalesce:1;	/* Needs software IRQ coalescing */

   Perhaps something shorter, like coalesce_irqs?

[...]

MBR, Sergey