[<prev] [next>] [<thread-prev] [thread-next>] [day] [month] [year] [list]
Message-ID: <66667ef2-2e0b-3c31-66ad-d6d6514919c7@omp.ru>
Date: Fri, 19 Apr 2024 23:32:16 +0300
From: Sergey Shtylyov <s.shtylyov@....ru>
To: Paul Barker <paul.barker.ct@...renesas.com>, "David S. Miller"
<davem@...emloft.net>, Eric Dumazet <edumazet@...gle.com>, Jakub Kicinski
<kuba@...nel.org>, Paolo Abeni <pabeni@...hat.com>
CC: Niklas Söderlund <niklas.soderlund+renesas@...natech.se>,
Geert Uytterhoeven <geert+renesas@...der.be>, <netdev@...r.kernel.org>,
<linux-renesas-soc@...r.kernel.org>, <linux-kernel@...r.kernel.org>
Subject: Re: [net-next RFC v3 6/7] net: ravb: Use NAPI threaded mode on 1-core
CPUs with GbEth IP
On 4/15/24 12:48 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).
>
> 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@...renesas.com>
Reviewed-by: Sergey Shtylyov <s.shtylyov@....ru>
[...]
MBR, Sergey
Powered by blists - more mailing lists