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 BBF2929B778 for ; Tue, 11 Nov 2025 18:43:49 +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=1762886629; cv=none; b=al49sygyIFR3JtkNVoi0PbT8Q6LOskuMRSxy1utpTwJSHg8njGwDDwV8gpsa1w853YpegewQoFwaEwry9GHANQSd/3ingFnqSqWyDkCjn/fyhWv/gUh+YrSIYbmIC6bpzBPLvthEs9t9/c7iTbvuWKqioJxsUmofMR4+OBYj+Us= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1762886629; c=relaxed/simple; bh=vyyXyd7tBM34oR2vONwYUNFKJuNtRJLepQMsmBIQhRg=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=p5I5Yyhz+crjhn2Y6lwPYrLd4u9ScQdrhuermA4LEHKV0F6pTI9qFNWPuFJMqBxylvVMFOjMaq7WntvrDNu3MowpPolCgsI2/0YwzEMbg3LvQKkfNmbM5FozTJiSNquOwXj9VyJEp4t8xJrgR8iDWSzP6pc1XfiqX31mryDFV94= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=fGFN9lnp; 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="fGFN9lnp" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9C2BEC4CEF5; Tue, 11 Nov 2025 18:43:48 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1762886629; bh=vyyXyd7tBM34oR2vONwYUNFKJuNtRJLepQMsmBIQhRg=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=fGFN9lnp1MHOnKHNSH1SS8GizCuakUEJjWT8oXKYruIVaTIjrBNBVZP+x/9FWsiwe z6yxUwbUrwtT1FfitRxQ/U5bYemo1hy+Z7h/yNqvdqOejaTx9kwFmnkmfMwKWFa8pS q/2eA82qy2cq6uFQAyD6VU53aVUIxjXUgrktyv3uZ4v5NcMv/3YqMh93HSXhLlLmya 6NkyIFc55n3xeBecZrEHhAWlhHilUe0qgQuHV6YB2Bln/CZzbSIbKkAu8awnBUiOeE d/QwDM5wsA/AgCL5WNoTPQMRXEOtZk77Dn7bDShpeYNa5s7MWBWDCfrLy7X8mER5b4 ML5ktHUu2Ti3Q== Message-ID: Date: Tue, 11 Nov 2025 19:43:46 +0100 Precedence: bulk X-Mailing-List: mptcp@lists.linux.dev List-Id: List-Subscribe: List-Unsubscribe: MIME-Version: 1.0 User-Agent: Mozilla Thunderbird Beta Subject: Re: [PATCH v3 mptcp-next 2/7] mptcp: avoid unneeded subflow-level drops. Content-Language: en-GB, fr-BE To: Paolo Abeni , mptcp@lists.linux.dev Cc: Mat Martineau References: <6af807a4d56bcac85d0908e30251ffa6d28ea38f.1762504059.git.pabeni@redhat.com> 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: <6af807a4d56bcac85d0908e30251ffa6d28ea38f.1762504059.git.pabeni@redhat.com> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Paolo, On 07/11/2025 09:32, Paolo Abeni wrote: > The rcv window is shared among all the subflows. Currently, MPTCP sync > the TCP-level rcv window with the MPTCP one at tcp_transmit_skb() time. > > The above means that incoming data may sporadically observe outdated > TCP-level rcv window and being wrongly dropped by TCP. > > Address the issue checking for the edge condition before queuing the data > at TCP level, and eventually syncing the rcv window as needed. > > Note that the issue is actually present from the very first MPTCP > implementation, but backports older than the blamed commit below will range > from impossible to useless. Thank you for this patch! It looks good to me: Reviewed-by: Matthieu Baerts (NGI0) > Before: > nstat >/dev/null ;sleep 1; nstat -z TcpExtBeyondWindow > TcpExtBeyondWindow 14 0.0 > > After: > nstat >/dev/null ;sleep 1; nstat -z TcpExtBeyondWindow > TcpExtBeyondWindow 0 0.0 Should we eventually track this MIB counter in mptcp_connect.sh? > Fixes: fa3fe2b15031 ("mptcp: track window announced to peer") While there are still discussions on patch 6/7, to ease things, I suggest already applying only this patch in our tree (fixes for -net), the only material for 'net' from what I understood. Cheers, Matt -- Sponsored by the NGI0 Core fund.