From: Jakub Kicinski <kuba@kernel.org>
To: <zhaoping.shu@mediatek.com>
Cc: <davem@davemloft.net>, <edumazet@google.com>, <pabeni@redhat.com>,
<horms@kernel.org>, <ncardwell@google.com>, <kuniyu@google.com>,
<matthias.bgg@gmail.com>,
<angelogioacchino.delregno@collabora.com>, <willemb@google.com>,
<alice@isovalent.com>, <sd@queasysnail.net>,
<eilaimemedsnaimel@gmail.com>, <imv4bel@gmail.com>,
<hw.he@mediatek.com>, <netdev@vger.kernel.org>,
<linux-kernel@vger.kernel.org>,
<linux-arm-kernel@lists.infradead.org>,
<linux-mediatek@lists.infradead.org>, <haijun.liu@mediatek.com>,
<xiayu.zhang@mediatek.com>, <lambert.wang@mediatek.com>,
<Iven.Yang@mediatek.com>
Subject: Re: [PATCH net v2] net: gro: avoid nesting TCP GSO skbs in skb_gro_receive_list()
Date: Thu, 23 Jul 2026 06:39:35 -0700 [thread overview]
Message-ID: <20260723063935.75bf55e3@kernel.org> (raw)
In-Reply-To: <20260723091601.72103-1-zhaoping.shu@mediatek.com>
On Thu, 23 Jul 2026 17:16:01 +0800 zhaoping.shu@mediatek.com wrote:
> From: HW He <hw.he@mediatek.com>
>
> On devices that support both NETIF_F_GRO_HW and NETIF_F_GRO_FRAGLIST,
"devices that support FRAGLIST"? Isn't it a software feature?
> the hardware or driver may deliver packets that have already been
If you have a driver in mind please name it.
> aggregated into a TCP GSO skb with frags[]. GRO may then
> aggregate the skb again in skb_gro_receive_list().
>
> This can create a nested GSO skb, which is not handled correctly by the
> later GSO segmentation paths. When the skb is segmented by
> skb_segment_list(), it not be fully restored to the original packets.
>
> Avoid this by setting NAPI_GRO_CB(skb)->flush for GSO skbs before
> aggregation.
I don't think we can do this. For GRO_HW devices re-aggregating
in SW is quite helpful, HW often runs out of contexts or times
out too soon, generating skbs with 16kB..32kB of data, the SW
can help bring it up to full TSO.
Also - you're missing a Fixes tag.
next prev parent reply other threads:[~2026-07-23 13:39 UTC|newest]
Thread overview: 3+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-07-23 9:16 [PATCH net v2] net: gro: avoid nesting TCP GSO skbs in skb_gro_receive_list() zhaoping.shu
2026-07-23 13:39 ` Jakub Kicinski [this message]
2026-07-23 14:02 ` Willem de Bruijn
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=20260723063935.75bf55e3@kernel.org \
--to=kuba@kernel.org \
--cc=Iven.Yang@mediatek.com \
--cc=alice@isovalent.com \
--cc=angelogioacchino.delregno@collabora.com \
--cc=davem@davemloft.net \
--cc=edumazet@google.com \
--cc=eilaimemedsnaimel@gmail.com \
--cc=haijun.liu@mediatek.com \
--cc=horms@kernel.org \
--cc=hw.he@mediatek.com \
--cc=imv4bel@gmail.com \
--cc=kuniyu@google.com \
--cc=lambert.wang@mediatek.com \
--cc=linux-arm-kernel@lists.infradead.org \
--cc=linux-kernel@vger.kernel.org \
--cc=linux-mediatek@lists.infradead.org \
--cc=matthias.bgg@gmail.com \
--cc=ncardwell@google.com \
--cc=netdev@vger.kernel.org \
--cc=pabeni@redhat.com \
--cc=sd@queasysnail.net \
--cc=willemb@google.com \
--cc=xiayu.zhang@mediatek.com \
--cc=zhaoping.shu@mediatek.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox