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 3110423DEBA for ; Tue, 10 Dec 2024 12:03:07 +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=1733832188; cv=none; b=SiSqfaakUkNZtfpJjQ8lXUqiB9ekv8MwhP1S7JrnljN/v3B54vqX+etLeU/BusDb2AURiUqH71TobsgGQz7K70TUYPmfesMOdGlPatJgENygAMdzpsZn+SbUQufKoOM790qonzBnZvOe4fwplVu0SmCiVQ/CVheJo+KmgdZrlGE= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1733832188; c=relaxed/simple; bh=MSLmfQbkb1ZLQVnwXt1z/jWB1ffxioY5hZN3b/u8wnI=; h=Message-ID:Date:MIME-Version:Subject:To:References:From:Cc: In-Reply-To:Content-Type; b=kXl/l1NOC+lmvNg7HemIXpZAz0wbDo2/zdBvi8mKPVqTymGcGnaQ4snoWUb7C158JqIU+DPZAA+vMZ/izW3iBy2reCkxwcmkwgJ3MJUD8/jHMd49/rm+AmvtiiaILHFUx33nVbhTriDVgshcEQ3Zxa4jIsvPaJGCxM8Bw9kQ9Kg= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=GFOGqt/v; 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="GFOGqt/v" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 38C74C4CEDE; Tue, 10 Dec 2024 12:03:07 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1733832187; bh=MSLmfQbkb1ZLQVnwXt1z/jWB1ffxioY5hZN3b/u8wnI=; h=Date:Subject:To:References:From:Cc:In-Reply-To:From; b=GFOGqt/v0x2n8JGZgs3D+3BPsiN8CAj1MUJwOCG9c9UE0V80ZjbCctd9FgJR6cO66 /CzOsyZ3XdCRorEdJ0asUa7IfyOXYs3q9ee/bAyukwt3u6rtRW81eNgfYsbIIKqvft clkCUNdyJde+DB++G5hLLL/DdRpGWpR8lGyqhwgFKdv6tRhIbqr1I1rJf9FyvZIuFK vJpQ9732t7l73TtqJgN3cAnMrlYtYoJ8kMlouL9npWUQADhYRncqJeehDbxmSL6qCP UmcN0+KaxuoMFal7dE6gHAUOu8KgDrZ01Q25WbEUDCsVAZrgH9q/xnNB8lQfSPo4Jq mb+UUDltfsXdg== Message-ID: <70d5e604-26e1-43f0-a36d-504d2b99c584@kernel.org> Date: Tue, 10 Dec 2024 13:03:05 +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 mptcp-next v2 1/7] mptcp: prevent excessive coalescing on receive Content-Language: en-GB To: Paolo Abeni References: <9c5947ad3b55695cb6000900acad5471b7314195.1733486870.git.pabeni@redhat.com> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Paolo, On 06/12/2024 13:10, Paolo Abeni wrote: > Currently the skb size after coalescing is only limited by the skb > layout (the skb must not carry frag_list). A single coalesced skb > covering several MSS can potentially fill completely the receive > buffer. In such a case, the snd win will zero until the receive buffer > will be empty again, affecting tput badly. Good idea! Thank you for having looked at this! > Signed-off-by: Paolo Abeni > --- > No fixes tag because the problem is not very visible in practice > currently, but will be apparent after the rx refactor. > Still I hope this could affect positively the simlut flows self-tests The modification looks safe enough to me: it should not make thing worst. If it helps, a Fixes tag can be added and next to the 'Cc: stable' tag, we can ask to backport this patch after a few weeks, no? e.g. Cc: # after -rc6 Cheers, Matt -- Sponsored by the NGI0 Core fund.