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Date:   Fri, 22 Jan 2021 17:43:25 -0800
From:   Jakub Kicinski <kuba@kernel.org>
To:     Enke Chen <enkechen2020@gmail.com>
Cc:     Eric Dumazet <edumazet@google.com>,
        "David S. Miller" <davem@davemloft.net>,
        Alexey Kuznetsov <kuznet@ms2.inr.ac.ru>,
        Hideaki YOSHIFUJI <yoshfuji@linux-ipv6.org>,
        netdev@vger.kernel.org, linux-kernel@vger.kernel.org,
        Neal Cardwell <ncardwell@google.com>
Subject: Re: [PATCH net] tcp: make TCP_USER_TIMEOUT accurate for zero window
 probes
Message-ID: <20210122174325.269ac329@kicinski-fedora-pc1c0hjn.dhcp.thefacebook.com>
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On Fri, 22 Jan 2021 11:13:06 -0800 Enke Chen wrote:
> From: Enke Chen <enchen@paloaltonetworks.com>
> 
> The TCP_USER_TIMEOUT is checked by the 0-window probe timer. As the
> timer has backoff with a max interval of about two minutes, the
> actual timeout for TCP_USER_TIMEOUT can be off by up to two minutes.
> 
> In this patch the TCP_USER_TIMEOUT is made more accurate by taking it
> into account when computing the timer value for the 0-window probes.
> 
> This patch is similar to the one that made TCP_USER_TIMEOUT accurate for
> RTOs in commit b701a99e431d ("tcp: Add tcp_clamp_rto_to_user_timeout()
> helper to improve accuracy").
> 
> Signed-off-by: Enke Chen <enchen@paloaltonetworks.com>
> Reviewed-by: Neal Cardwell <ncardwell@google.com>

This is targeting net, any guidance on Fixes / backporting?