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Date:   Wed, 28 Jul 2021 12:12:44 +0200
From:   Pavel Machek <pavel@denx.de>
To:     Greg Kroah-Hartman <gregkh@linuxfoundation.org>
Cc:     linux-kernel@vger.kernel.org, stable@vger.kernel.org,
        Wei Wang <weiwan@google.com>,
        Eric Dumazet <edumazet@google.com>,
        Neal Cardwell <ncardwell@google.com>,
        Soheil Hassas Yeganeh <soheil@google.com>,
        Yuchung Cheng <ycheng@google.com>,
        "David S. Miller" <davem@davemloft.net>,
        Sasha Levin <sashal@kernel.org>
Subject: Re: [PATCH 5.10 099/167] tcp: disable TFO blackhole logic by default
Message-ID: <20210728101244.GB30574@amd>
References: <20210726153839.371771838@linuxfoundation.org>
 <20210726153842.719316961@linuxfoundation.org>
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Hi!

> [ Upstream commit 213ad73d06073b197a02476db3a4998e219ddb06 ]
>=20
> Multiple complaints have been raised from the TFO users on the internet
> stating that the TFO blackhole logic is too aggressive and gets falsely
> triggered too often.
> (e.g. https://blog.apnic.net/2021/07/05/tcp-fast-open-not-so-fast/)
> Considering that most middleboxes no longer drop TFO packets, we decide
> to disable the blackhole logic by setting
> /proc/sys/net/ipv4/tcp_fastopen_blackhole_timeout_set to 0 by
> default.

I understand this makes sense for mainline, but should we have this in
stable? Somebody may still be using broken middlebox with their
"stable" server.

Best regards,
								Pavel

--=20
DENX Software Engineering GmbH,      Managing Director: Wolfgang Denk
HRB 165235 Munich, Office: Kirchenstr.5, D-82194 Groebenzell, Germany

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