Received-SPF: pass (google.com: domain of linux-kernel+bounces-166649-linux.lists.archive=gmail.com@vger.kernel.org designates 147.75.199.223 as permitted sender) client-ip=147.75.199.223;
Message-ID: <d35c96ca-3c28-4745-a323-949365f5033a@kernel.org>
Date: Thu, 2 May 2024 09:33:05 -0600
Precedence: bulk
MIME-Version: 1.0
User-Agent: Mozilla Thunderbird
Subject: Re: [PATCH v5 net-next v5 6/6] net: add heuristic for enabling TCP
 fraglist GRO
Content-Language: en-US
To: Felix Fietkau <nbd@nbd.name>, netdev@vger.kernel.org,
 Eric Dumazet <edumazet@google.com>, "David S. Miller" <davem@davemloft.net>,
 Jakub Kicinski <kuba@kernel.org>, Paolo Abeni <pabeni@redhat.com>
Cc: willemdebruijn.kernel@gmail.com, linux-kernel@vger.kernel.org
References: <20240502084450.44009-1-nbd@nbd.name>
 <20240502084450.44009-7-nbd@nbd.name>
From: David Ahern <dsahern@kernel.org>
In-Reply-To: <20240502084450.44009-7-nbd@nbd.name>
Content-Type: text/plain; charset=UTF-8
Content-Transfer-Encoding: 7bit

On 5/2/24 2:44 AM, Felix Fietkau wrote:
> When forwarding TCP after GRO, software segmentation is very expensive,
> especially when the checksum needs to be recalculated.
> One case where that's currently unavoidable is when routing packets over
> PPPoE. Performance improves significantly when using fraglist GRO
> implemented in the same way as for UDP.
> 
> When NETIF_F_GRO_FRAGLIST is enabled, perform a lookup for an established
> socket in the same netns as the receiving device. While this may not
> cover all relevant use cases in multi-netns configurations, it should be
> good enough for most configurations that need this.
> 
> Here's a measurement of running 2 TCP streams through a MediaTek MT7622
> device (2-core Cortex-A53), which runs NAT with flow offload enabled from
> one ethernet port to PPPoE on another ethernet port + cake qdisc set to
> 1Gbps.
> 
> rx-gro-list off: 630 Mbit/s, CPU 35% idle
> rx-gro-list on:  770 Mbit/s, CPU 40% idle
> 
> Acked-by: Paolo Abeni <pabeni@redhat.com>
> Reviewed-by: Eric Dumazet <edumazet@google.com>
> Signed-off-by: Felix Fietkau <nbd@nbd.name>
> ---
>  net/ipv4/tcp_offload.c   | 32 ++++++++++++++++++++++++++++++++
>  net/ipv6/tcpv6_offload.c | 35 +++++++++++++++++++++++++++++++++++
>  2 files changed, 67 insertions(+)
> 

Reviewed-by: David Ahern <dsahern@kernel.org>