From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from smtp.kernel.org (aws-us-west-2-korg-mail-1.web.codeaurora.org [10.30.226.201]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by smtp.subspace.kernel.org (Postfix) with ESMTPS id E820F155321; Tue, 23 Jul 2024 14:40:20 +0000 (UTC) Authentication-Results: smtp.subspace.kernel.org; arc=none smtp.client-ip=10.30.226.201 ARC-Seal:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721745621; cv=none; b=YghRTXdK2+2KH3upF8gy5aXc7tD96KoDR7h9nWbpzZVmcoyMYwghOPcgXjKy9b4bL3MfO+RsGPbCP/1wBJOsiHV0QDlaYTuqB1cV5eeZmrmG3mAAm9HmyzNN+5CQL6yc3LUOQCqizTwhgfizuOG2A094ZFlwI4f90acmPwLRyqQ= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1721745621; c=relaxed/simple; bh=N8ZTdNmUIqz46MN1E8bCcCXKIVjipICXzUH6FEPlH+A=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=NxcJZ9pZtdlUoRULEvFCfukvZC568sWIxRZh1+SxfOOHeSA7OTq3YoIIMuW9+L3vye2SPOLBFRAsj8RCU5odj7lrPnbLgQyf2hx/IYP1fLOUMX848y85uMNR/QVmmVwiMBswa0JOKz2bNDVJckkahf04caVsPhHQ+XTJknxgWeU= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=r83cRjq8; arc=none smtp.client-ip=10.30.226.201 Authentication-Results: smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b="r83cRjq8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 50F45C4AF09; Tue, 23 Jul 2024 14:40:18 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1721745620; bh=N8ZTdNmUIqz46MN1E8bCcCXKIVjipICXzUH6FEPlH+A=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=r83cRjq8zL5dGH2mSTsXbVvYysAjvKNHVPhYRD+xsmj6r9UeouHF81UVh1PhtJdxa BsoMn7WytP2wEODGPB2Mt8PmGwx8E1z5Bg2V0eBvFpYjLUdXu9VnaUrub8B4mM0uFL y2eUXA83RY7dGnqxIgLgEt27cyANq5kXFC1p1lYOHTBpZQYesT+li2Y5EU14DV8Pti 1Ahomm1bMqyI/ecdCG1vqL7KjDCVef7GqzScZrF0MCVkYWkmB4zWrjTumLcou11oZX 9Aicvl99c0XCmwbys8Va9t/Tc9itI3UCOZtm+jeSUIYivS+WdNdDmAKuaOIcBz0ljx Q4J/uhxoNRMCw== Message-ID: Date: Tue, 23 Jul 2024 16:40:08 +0200 Precedence: bulk X-Mailing-List: linux-kernel@vger.kernel.org List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH net v2 2/2] tcp: limit wake-up for crossed SYN cases to SYN-ACK Content-Language: en-GB To: Eric Dumazet Cc: "David S. Miller" , David Ahern , Jakub Kicinski , Paolo Abeni , Kuniyuki Iwashima , Jerry Chu , netdev@vger.kernel.org, mptcp@lists.linux.dev, linux-kernel@vger.kernel.org References: <20240718-upstream-net-next-20240716-tcp-3rd-ack-consume-sk_socket-v2-0-d653f85639f6@kernel.org> <20240718-upstream-net-next-20240716-tcp-3rd-ack-consume-sk_socket-v2-2-d653f85639f6@kernel.org> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; keydata= xsFNBFXj+ekBEADxVr99p2guPcqHFeI/JcFxls6KibzyZD5TQTyfuYlzEp7C7A9swoK5iCvf YBNdx5Xl74NLSgx6y/1NiMQGuKeu+2BmtnkiGxBNanfXcnl4L4Lzz+iXBvvbtCbynnnqDDqU c7SPFMpMesgpcu1xFt0F6bcxE+0ojRtSCZ5HDElKlHJNYtD1uwY4UYVGWUGCF/+cY1YLmtfb WdNb/SFo+Mp0HItfBC12qtDIXYvbfNUGVnA5jXeWMEyYhSNktLnpDL2gBUCsdbkov5VjiOX7 CRTkX0UgNWRjyFZwThaZADEvAOo12M5uSBk7h07yJ97gqvBtcx45IsJwfUJE4hy8qZqsA62A nTRflBvp647IXAiCcwWsEgE5AXKwA3aL6dcpVR17JXJ6nwHHnslVi8WesiqzUI9sbO/hXeXw TDSB+YhErbNOxvHqCzZEnGAAFf6ges26fRVyuU119AzO40sjdLV0l6LE7GshddyazWZf0iac nEhX9NKxGnuhMu5SXmo2poIQttJuYAvTVUNwQVEx/0yY5xmiuyqvXa+XT7NKJkOZSiAPlNt6 VffjgOP62S7M9wDShUghN3F7CPOrrRsOHWO/l6I/qJdUMW+MHSFYPfYiFXoLUZyPvNVCYSgs 3oQaFhHapq1f345XBtfG3fOYp1K2wTXd4ThFraTLl8PHxCn4ywARAQABzSRNYXR0aGlldSBC YWVydHMgPG1hdHR0YmVAa2VybmVsLm9yZz7CwZEEEwEIADsCGwMFCwkIBwIGFQoJCAsCBBYC AwECHgECF4AWIQToy4X3aHcFem4n93r2t4JPQmmgcwUCZUDpDAIZAQAKCRD2t4JPQmmgcz33 EACjROM3nj9FGclR5AlyPUbAq/txEX7E0EFQCDtdLPrjBcLAoaYJIQUV8IDCcPjZMJy2ADp7 /zSwYba2rE2C9vRgjXZJNt21mySvKnnkPbNQGkNRl3TZAinO1Ddq3fp2c/GmYaW1NWFSfOmw MvB5CJaN0UK5l0/drnaA6Hxsu62V5UnpvxWgexqDuo0wfpEeP1PEqMNzyiVPvJ8bJxgM8qoC cpXLp1Rq/jq7pbUycY8GeYw2j+FVZJHlhL0w0Zm9CFHThHxRAm1tsIPc+oTorx7haXP+nN0J iqBXVAxLK2KxrHtMygim50xk2QpUotWYfZpRRv8dMygEPIB3f1Vi5JMwP4M47NZNdpqVkHrm jvcNuLfDgf/vqUvuXs2eA2/BkIHcOuAAbsvreX1WX1rTHmx5ud3OhsWQQRVL2rt+0p1DpROI 3Ob8F78W5rKr4HYvjX2Inpy3WahAm7FzUY184OyfPO/2zadKCqg8n01mWA9PXxs84bFEV2mP VzC5j6K8U3RNA6cb9bpE5bzXut6T2gxj6j+7TsgMQFhbyH/tZgpDjWvAiPZHb3sV29t8XaOF BwzqiI2AEkiWMySiHwCCMsIH9WUH7r7vpwROko89Tk+InpEbiphPjd7qAkyJ+tNIEWd1+MlX ZPtOaFLVHhLQ3PLFLkrU3+Yi3tXqpvLE3gO3LM7BTQRV4/npARAA5+u/Sx1n9anIqcgHpA7l 5SUCP1e/qF7n5DK8LiM10gYglgY0XHOBi0S7vHppH8hrtpizx+7t5DBdPJgVtR6SilyK0/mp 9nWHDhc9rwU3KmHYgFFsnX58eEmZxz2qsIY8juFor5r7kpcM5dRR9aB+HjlOOJJgyDxcJTwM 1ey4L/79P72wuXRhMibN14SX6TZzf+/XIOrM6TsULVJEIv1+NdczQbs6pBTpEK/G2apME7vf mjTsZU26Ezn+LDMX16lHTmIJi7Hlh7eifCGGM+g/AlDV6aWKFS+sBbwy+YoS0Zc3Yz8zrdbi Kzn3kbKd+99//mysSVsHaekQYyVvO0KD2KPKBs1S/ImrBb6XecqxGy/y/3HWHdngGEY2v2IP Qox7mAPznyKyXEfG+0rrVseZSEssKmY01IsgwwbmN9ZcqUKYNhjv67WMX7tNwiVbSrGLZoqf Xlgw4aAdnIMQyTW8nE6hH/Iwqay4S2str4HZtWwyWLitk7N+e+vxuK5qto4AxtB7VdimvKUs x6kQO5F3YWcC3vCXCgPwyV8133+fIR2L81R1L1q3swaEuh95vWj6iskxeNWSTyFAVKYYVskG V+OTtB71P1XCnb6AJCW9cKpC25+zxQqD2Zy0dK3u2RuKErajKBa/YWzuSaKAOkneFxG3LJIv Hl7iqPF+JDCjB5sAEQEAAcLBXwQYAQIACQUCVeP56QIbDAAKCRD2t4JPQmmgc5VnD/9YgbCr HR1FbMbm7td54UrYvZV/i7m3dIQNXK2e+Cbv5PXf19ce3XluaE+wA8D+vnIW5mbAAiojt3Mb 6p0WJS3QzbObzHNgAp3zy/L4lXwc6WW5vnpWAzqXFHP8D9PTpqvBALbXqL06smP47JqbyQxj Xf7D2rrPeIqbYmVY9da1KzMOVf3gReazYa89zZSdVkMojfWsbq05zwYU+SCWS3NiyF6QghbW voxbFwX1i/0xRwJiX9NNbRj1huVKQuS4W7rbWA87TrVQPXUAdkyd7FRYICNW+0gddysIwPoa KrLfx3Ba6Rpx0JznbrVOtXlihjl4KV8mtOPjYDY9u+8x412xXnlGl6AC4HLu2F3ECkamY4G6 UxejX+E6vW6Xe4n7H+rEX5UFgPRdYkS1TA/X3nMen9bouxNsvIJv7C6adZmMHqu/2azX7S7I vrxxySzOw9GxjoVTuzWMKWpDGP8n71IFeOot8JuPZtJ8omz+DZel+WCNZMVdVNLPOd5frqOv mpz0VhFAlNTjU1Vy0CnuxX3AM51J8dpdNyG0S8rADh6C8AKCDOfUstpq28/6oTaQv7QZdge0 JY6dglzGKnCi/zsmp2+1w559frz4+IC7j/igvJGX4KDDKUs0mlld8J2u2sBXv7CGxdzQoHaz lzVbFe7fduHbABmYz9cefQpO7wDE/Q== Organization: NGI0 Core In-Reply-To: Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Hi Eric, Thank you for the review! On 23/07/2024 16:32, Eric Dumazet wrote: > On Thu, Jul 18, 2024 at 12:34 PM Matthieu Baerts (NGI0) > wrote: >> >> sk->sk_socket will be assigned in case of marginal crossed SYN, but also >> in other cases, e.g. >> >> - With TCP Fast Open, if the connection got accept()'ed before >> receiving the 3rd ACK ; >> >> - With MPTCP, when accepting additional subflows to an existing MPTCP >> connection. >> >> In these cases, the switch to TCP_ESTABLISHED is done when receiving the >> 3rd ACK, without the SYN flag then. >> >> To properly restrict the wake-up to crossed SYN cases, it is then >> required to also limit the check to packets containing the SYN-ACK >> flags. >> >> While at it, also update the attached comment: sk->sk_sleep has been >> removed in 2010, and replaced by sk->sk_wq in commit 43815482370c ("net: >> sock_def_readable() and friends RCU conversion"). >> >> Fixes: 168a8f58059a ("tcp: TCP Fast Open Server - main code path") >> Suggested-by: Kuniyuki Iwashima >> Signed-off-by: Matthieu Baerts (NGI0) >> --- >> Notes: >> - The above 'Fixes' tag should correspond to the commit introducing the >> possibility to have sk->sk_socket being set there in other cases than >> the crossed SYN one. But I might have missed other cases. Maybe >> 1da177e4c3f4 ("Linux-2.6.12-rc2") might be safer? On the other hand, >> I don't think this wake-up was causing any visible issue, apart from >> not being needed. > > This seems a net-next candidate to me ? Fine by me! I modified this line mainly because Kuniyuki mentioned that it was the same check as the new one, modified in patch 1/2. I didn't find any visible issue with the wakeup, so I guess it can go to net-next. Cheers, Matt -- Sponsored by the NGI0 Core fund.