From: Paolo Abeni <pabeni@redhat.com>
To: chia-yu.chang@nokia-bell-labs.com, edumazet@google.com,
linux-doc@vger.kernel.org, corbet@lwn.net, horms@kernel.org,
dsahern@kernel.org, kuniyu@amazon.com, bpf@vger.kernel.org,
netdev@vger.kernel.org, dave.taht@gmail.com, jhs@mojatatu.com,
kuba@kernel.org, stephen@networkplumber.org,
xiyou.wangcong@gmail.com, jiri@resnulli.us, davem@davemloft.net,
andrew+netdev@lunn.ch, donald.hunter@gmail.com, ast@fiberby.net,
liuhangbin@gmail.com, shuah@kernel.org,
linux-kselftest@vger.kernel.org, ij@kernel.org,
ncardwell@google.com, koen.de_schepper@nokia-bell-labs.com,
g.white@cablelabs.com, ingemar.s.johansson@ericsson.com,
mirja.kuehlewind@ericsson.com, cheshire@apple.com,
rs.ietf@gmx.at, Jason_Livingood@comcast.com,
vidhi_goel@apple.com
Subject: Re: [PATCH v4 net-next 02/13] gro: flushing when CWR is set negatively affects AccECN
Date: Thu, 16 Oct 2025 11:17:06 +0200 [thread overview]
Message-ID: <98342f21-08c8-46de-9309-d58dfc44d0a0@redhat.com> (raw)
In-Reply-To: <20251013170331.63539-3-chia-yu.chang@nokia-bell-labs.com>
On 10/13/25 7:03 PM, chia-yu.chang@nokia-bell-labs.com wrote:
> From: Ilpo Järvinen <ij@kernel.org>
>
> As AccECN may keep CWR bit asserted due to different
> interpretation of the bit, flushing with GRO because of
> CWR may effectively disable GRO until AccECN counter
> field changes such that CWR-bit becomes 0.
>
> There is no harm done from not immediately forwarding the
> CWR'ed segment with RFC3168 ECN.
I guess this change could introduce additional latency for RFC3168
notification, which sounds not good. On the flip side adding too much
AccECN logic to GRO (i.e. to allow aggregation only for AccECN enabled
flows) looks overkill.
@Eric: WDYT?
Thanks,
Paolo
next prev parent reply other threads:[~2025-10-16 9:17 UTC|newest]
Thread overview: 25+ messages / expand[flat|nested] mbox.gz Atom feed top
2025-10-13 17:03 [PATCH v4 net-next 00/13] AccECN protocol case handling series chia-yu.chang
2025-10-13 17:03 ` [PATCH v4 net-next 01/13] tcp: try to avoid safer when ACKs are thinned chia-yu.chang
2025-10-13 17:03 ` [PATCH v4 net-next 02/13] gro: flushing when CWR is set negatively affects AccECN chia-yu.chang
2025-10-16 9:17 ` Paolo Abeni [this message]
2025-10-16 20:26 ` Ilpo Järvinen
2025-10-20 15:26 ` Chia-Yu Chang (Nokia)
2025-10-20 15:31 ` Eric Dumazet
2025-10-20 16:46 ` Chia-Yu Chang (Nokia)
2025-10-13 17:03 ` [PATCH v4 net-next 03/13] tcp: L4S ECT(1) identifier and NEEDS_ACCECN for CC modules chia-yu.chang
2025-10-13 17:03 ` [PATCH v4 net-next 04/13] tcp: disable RFC3168 fallback identifier " chia-yu.chang
2025-10-13 17:03 ` [PATCH v4 net-next 05/13] tcp: accecn: handle unexpected AccECN negotiation feedback chia-yu.chang
2025-10-16 9:02 ` Paolo Abeni
2025-10-13 17:03 ` [PATCH v4 net-next 06/13] tcp: accecn: retransmit downgraded SYN in AccECN negotiation chia-yu.chang
2025-10-13 17:03 ` [PATCH v4 net-next 07/13] tcp: move increment of num_retrans chia-yu.chang
2025-10-13 17:03 ` [PATCH v4 net-next 08/13] tcp: accecn: retransmit SYN/ACK without AccECN option or non-AccECN SYN/ACK chia-yu.chang
2025-10-16 9:13 ` Paolo Abeni
2025-10-18 16:06 ` Chia-Yu Chang (Nokia)
2025-10-13 17:03 ` [PATCH v4 net-next 09/13] tcp: accecn: unset ECT if receive or send ACE=0 in AccECN negotiaion chia-yu.chang
2025-10-13 17:03 ` [PATCH v4 net-next 10/13] tcp: accecn: fallback outgoing half link to non-AccECN chia-yu.chang
2025-10-13 17:03 ` [PATCH v4 net-next 11/13] tcp: accecn: verify ACE counter in 1st ACK after AccECN negotiation chia-yu.chang
2025-10-13 17:03 ` [PATCH v4 net-next 12/13] tcp: accecn: detect loss ACK w/ AccECN option and add TCP_ACCECN_OPTION_PERSIST chia-yu.chang
2025-10-16 9:25 ` Paolo Abeni
2025-10-13 17:03 ` [PATCH v4 net-next 13/13] tcp: accecn: enable AccECN chia-yu.chang
2025-10-16 10:08 ` [PATCH v4 net-next 00/13] AccECN protocol case handling series Jakub Sitnicki
-- strict thread matches above, loose matches on Subject: below --
2025-10-10 13:17 chia-yu.chang
2025-10-10 13:17 ` [PATCH v4 net-next 02/13] gro: flushing when CWR is set negatively affects AccECN chia-yu.chang
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