From: Jakub Kicinski <kuba@kernel.org>
To: Eric Dumazet <edumazet@google.com>
Cc: kuniyu@google.com, ncardwell@google.com, netdev@vger.kernel.org,
davem@davemloft.net, pabeni@redhat.com, andrew+netdev@lunn.ch,
horms@kernel.org
Subject: Re: [PATCH net-next] tcp: try to defer / return acked skbs to originating CPU
Date: Mon, 16 Feb 2026 09:49:36 -0800 [thread overview]
Message-ID: <20260216094936.5bf9d789@kernel.org> (raw)
In-Reply-To: <CANn89i+P86WVVUY-4WppUAH1TGix1Z3KhgX9vSHok5nXqQAiHQ@mail.gmail.com>
On Mon, 16 Feb 2026 17:06:58 +0100 Eric Dumazet wrote:
> > > Looks like selftests run into the zerocopy Tx latency issue.
> > > I'll drop this version from patchwork..
> >
> > Delaying zero copy forever is a bit of an annoyance.
> > I believe the same thing can happen in net-next with UDP
> > but I haven't tested to confirm.
> >
> > I assume the attached patch is out of question since it came up before?
>
> I think I totally missed your email :/
>
> What about not attempting defer for zero copy skbs ?
>
> It turns out existing patch e20dfbad8aab ("net: fix napi_consume_skb()
> with alien skbs") is already a problem for zcopy.
We definitely need either this or the timer patch I attached, for UDP.
I put the TCP write side on a back burner because slab sheaves got
merged, I think skb defer free will still make a difference but IDK
how much. Maybe juice will no longer be worth the squeeze?
next prev parent reply other threads:[~2026-02-16 17:49 UTC|newest]
Thread overview: 15+ messages / expand[flat|nested] mbox.gz Atom feed top
2026-01-17 16:42 [PATCH net-next] tcp: try to defer / return acked skbs to originating CPU Jakub Kicinski
2026-01-17 17:10 ` Jakub Kicinski
2026-01-17 18:16 ` Eric Dumazet
2026-01-17 23:03 ` Jakub Kicinski
2026-01-18 12:15 ` Eric Dumazet
2026-01-19 17:04 ` Jakub Kicinski
2026-01-29 23:04 ` Jakub Kicinski
2026-01-29 23:10 ` Jakub Kicinski
2026-02-16 16:06 ` Eric Dumazet
2026-02-16 17:49 ` Jakub Kicinski [this message]
2026-02-16 17:58 ` Eric Dumazet
2026-02-16 18:11 ` Jakub Kicinski
2026-02-16 18:16 ` Eric Dumazet
2026-02-17 21:50 ` Jakub Kicinski
2026-02-17 21:56 ` Eric Dumazet
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