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 45E0C13C83E for ; Tue, 7 May 2024 08:12:45 +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=1715069565; cv=none; b=RqQcRVPigq+S9VEhX/VMyCU4R8Wmso6OscxTa5cEgYXvGkKwtFCS0/WCZaKPS8/QlTgmx2WZj3XxP1EckSy0KlCTn1zn8RIw/9/tRN1ZzcK7e5XrU6wZ2iff+yGtd+RvdwIObJrAzqtl0U5eeRk6CVBPUGVBn4K3xNbTbH1Ebzw= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1715069565; c=relaxed/simple; bh=NXh+amqcHZFILwCx51DtFWxrj2ewpyihCsc2qrgHac4=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=Mqrh1MhRvinl5CAggewFVjd6BnjRwv8OP59TT6QTKbNo60FPNF8pV6GELcyGJLN98UGoVA1lhyyebKNGVLqbd2vJVF75McqGFJjGj4Vz2Pu5NTbqw1v58yg/GoAHgFUuIigOvUVtpDC1f+nykRkDjyj9cHGOhhWenoLwGrGf02o= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=Ygffgf25; 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="Ygffgf25" Received: by smtp.kernel.org (Postfix) with ESMTPSA id 9CAD4C2BBFC; Tue, 7 May 2024 08:12:43 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1715069565; bh=NXh+amqcHZFILwCx51DtFWxrj2ewpyihCsc2qrgHac4=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=Ygffgf25C8DRPPj5FhxuFrrNc3XODCoYxilfbPmY0jyAMh7WizuVAFm44eZfRtbX0 MwwK1/FqPChCM3L/rnUReEMPte6d4B57xf78fiNcF4A3z4rpF9BcC6pn1JnQkHZp8r /o50XfzSmX17iFDiVCz9J+N8KzRk+p/jdlROVg2ohQPyav6LTUbdNx5FnJpvtOPp3r 87CEcqQBitUua9KNaRN9h7lSH5qIyMSER0Gqs/CRNdD87Ak0bhFvEpBDDgGe2xWO8R xDdgyPYEFZ00P4S3W2ae3K2BgZ8EQYa6d8gTM6cZGM/IsyxR30uXumpGiVh6551rNp 7Ajn0Lm7kxt8w== Message-ID: <7f9f2b7f-9bb5-4c17-bdef-c96fe2707d27@kernel.org> Date: Tue, 7 May 2024 10:12:41 +0200 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-net v2] mptcp: fix the default value of scaling_ratio Content-Language: en-GB To: Geliang Tang , mptcp@lists.linux.dev Cc: martin.lau@kernel.org, Geliang Tang , Paolo Abeni References: <0ccc1c26d27d6ee7be22806a97983d37c6ca548c.1715053270.git.tanggeliang@kylinos.cn> From: Matthieu Baerts Autocrypt: addr=matttbe@kernel.org; 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charset=UTF-8 Content-Transfer-Encoding: 7bit Hi Geliang, (+cc Paolo who wrote the commit mentioned by the "Fixes" tag) On 07/05/2024 05:46, Geliang Tang wrote: > From: Geliang Tang > > BPF tests fail sometimes with "bytes != total_bytes" errors: > > test_default:PASS:sched_init:default 0 nsec > send_data:PASS:pthread_create 0 nsec > send_data:FAIL:recv 936000 != 10485760 nr_recv:-1 errno:11 > default: 3041 ms > server:FAIL:send 7579500 != 10485760 nr_sent:-1 errno:11 > send_data:FAIL:pthread_join thread_ret:-11 test_default:PASS: \ > has_bytes_sent addr_1 0 nsec > test_default:PASS:has_bytes_sent addr_2 0 nsec > close_netns:PASS:setns 0 nsec > > In this case mptcp_recvmsg() gets EAGAIN errors. This issue introduces > by commit b8dc6d6ce931 ("mptcp: fix rcv buffer auto-tuning"). The default > value of scaling_ratio should be TCP_DEFAULT_SCALING_RATIO, not U8_MAX. It looks like you are modifying the max value, not the default one. Also, please always explain the reason: why should it be X, not Y? > > Fixes: b8dc6d6ce931 ("mptcp: fix rcv buffer auto-tuning") > Closes: https://github.com/multipath-tcp/mptcp_net-next/issues/487 > Signed-off-by: Geliang Tang > --- > v2: > - I finally found the root cause of this issue. > - cc Martin too. > --- > net/mptcp/protocol.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/net/mptcp/protocol.c b/net/mptcp/protocol.c > index 579031c60937..d00cd21e8d3f 100644 > --- a/net/mptcp/protocol.c > +++ b/net/mptcp/protocol.c > @@ -1981,9 +1981,9 @@ static int __mptcp_recvmsg_mskq(struct mptcp_sock *msk, > */ > static void mptcp_rcv_space_adjust(struct mptcp_sock *msk, int copied) > { > + u8 scaling_ratio = TCP_DEFAULT_SCALING_RATIO; With this modification, you are limiting msk->scaling_ratio to TCP_DEFAULT_SCALING_RATIO. That's probably not what you want. See below: (...) mptcp_for_each_subflow(msk, subflow) (...) scaling_ratio = min(tp->scaling_ratio, scaling_ratio); (...) msk->scaling_ratio = scaling_ratio; Do you mean that in your case, msk->scaling_ratio was assigned to U8_MAX? Or it was assigned to a too high value (>TCP_DEFAULT_SCALING_RATIO)? Please add such info in the commit message as well. > struct mptcp_subflow_context *subflow; > struct sock *sk = (struct sock *)msk; > - u8 scaling_ratio = U8_MAX; > u32 time, advmss = 1; > u64 rtt_us, mstamp; > Cheers, Matt -- Sponsored by the NGI0 Core fund.