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From: "Alexei Starovoitov" <alexei.starovoitov@gmail.com>
To: "Antonio Quartulli" <antonio@mandelbit.com>
Cc: <saeedm@nvidia.com>, <leon@kernel.org>, <tariqt@nvidia.com>,
	<mbloch@nvidia.com>, <dtatulea@nvidia.com>, <cratiu@nvidia.com>,
	<andrew+netdev@lunn.ch>, <davem@davemloft.net>,
	<netdev@vger.kernel.org>, <edumazet@kernel.org>,
	<kuba@kernel.org>, <pabeni@redhat.com>, <daniel@iogearbox.net>,
	<hawk@kernel.org>, <john.fastabend@gmail.com>, <sdf@fomichev.me>,
	<linux-rdma@vger.kernel.org>, <bpf@vger.kernel.org>,
	<linux-kernel@vger.kernel.org>
Subject: Re: [PATCH net-next] net/mlx5e: Prefetch packets of upcoming CQEs in the linear MPWQE path
Date: Wed, 04 Nov 2026 20:14:36 +0000	[thread overview]
Message-ID: <DMMPA4SE5V7I.BQOTSW259XNA@gmail.com> (raw)
In-Reply-To: <f4bdb8b8-45d6-477d-bd7f-4ca4bbafef7c@mandelbit.com>

On Wed Nov 4, 2026 at 7:46 PM UTC, Antonio Quartulli wrote:
> Hi Alexei,
>
> thank you very much for the review!!
>
> On 04/11/2026 01:39, Alexei Starovoitov wrote:
>> can we prefetch 4 strides ahead without the CQE, like gve_rx() ?
>
> Yep! I measured your version against this patch on the same system (one
> RX queue, MTU 1500, mean of 3 runs, gain over stock):
>
>                                     v1      yours    yours + shinfo
>    UDP 512B flood, packets/s       +39%      +35%      +36%
>    TCP, 1 stream                    +7%       +5%       +8%
>    TCP in an ovpn UDP tunnel       +36%       +4%      +34%
>    XDP_DROP reading the packet,
>      NAPI CPU cycles/packet        -38%      -45%      -32%
>    XDP_TX, cycles/packet           -35%      -30%      -33%
>
>
> It matches my v1, except where every packet becomes its own skb, like the
> records of a VPN tunnel (ovpn from a development tree here).
> In that case I got only +4% instead of +36%.
> Dropping only the skb_shared_info prefetch from v1 gives +5% there, so
> that line is the one that matters.

Thanks for the benchmarks. Glad it helped.

      reply	other threads:[~2026-11-04 20:14 UTC|newest]

Thread overview: 4+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2026-11-03 23:58 [PATCH net-next] net/mlx5e: Prefetch packets of upcoming CQEs in the linear MPWQE path Antonio Quartulli
2026-11-04  0:39 ` Alexei Starovoitov
2026-11-04 19:46   ` Antonio Quartulli
2026-11-04 20:14     ` Alexei Starovoitov [this message]

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