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 4FFFF145320 for ; Mon, 22 Apr 2024 10:31:30 +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=1713781891; cv=none; b=OrAbbyTdsfC5uCfpZg3oPQlNy+IsMiRCio8WC0oaTHE1yTax+YgYmga+ez5eIhFIK9TdjiwFV/G9WY4c/exY2sTtmOx8scQslITMO2ikVSMp0atPX8TYKilfvtWxuYfO3lNEGemqwlyIq5vteVEzhpPWS7HCnwEp29lqZ1VKVfg= ARC-Message-Signature:i=1; a=rsa-sha256; d=subspace.kernel.org; s=arc-20240116; t=1713781891; c=relaxed/simple; bh=4oygYQwHfuoEoklI7/Qgzhik9hlSOYSR0H7M21jj1KA=; h=Message-ID:Date:MIME-Version:Subject:To:Cc:References:From: In-Reply-To:Content-Type; b=cNodTWrr35rYlRRj50OK8swJu8nHxsL6YnWFygJsrtciWEhp/dqF+I6Vg1N34+WTnjLnMOSpDhtS9PYBZ7b8MZXHWa7/T9P6xto3vUPU1IgJckMxuyvsRmjEV/6xxzW19HY6z/GSO9AN94rMAl1BdcBvio5+LvOAnbMuQVJcIe0= ARC-Authentication-Results:i=1; smtp.subspace.kernel.org; dkim=pass (2048-bit key) header.d=kernel.org header.i=@kernel.org header.b=QMFCyaw8; 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="QMFCyaw8" Received: by smtp.kernel.org (Postfix) with ESMTPSA id D541AC113CC; Mon, 22 Apr 2024 10:31:28 +0000 (UTC) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/simple; d=kernel.org; s=k20201202; t=1713781890; bh=4oygYQwHfuoEoklI7/Qgzhik9hlSOYSR0H7M21jj1KA=; h=Date:Subject:To:Cc:References:From:In-Reply-To:From; b=QMFCyaw8Cl4ZUGQw62HPi7ZJ+UtUJXl/jlGWuF9XRCP8cocmC0KDjZ2fThp0dnUXb aXy0QBJuOWEimt/peqjZygUCgxlZbXgE86S0PlA/JWL01BHNIYSa7b2cKh0pu2K8jT Rqfv2YRIqKGoJPxcafQWLqdtG+GMJqJZdey4ceDnbqtmlWNtSkuIZ1+4ahYwoaKkDm WLv9HlkHBqukcNonBf9UpN/TnYi1HL1ABUGBHCCIW2t1v/06RnG7Qb4SfC/WRETCof 5jXNWaEfCa9G3ddAr+gnsuZloJXAb/9gRIXruvkI1r/6QWZALJdIepjZ9X/yBM8+9T PXP6pN0WQefJA== Message-ID: <0017e477-3fcd-45de-917b-b58b3781ca9b@kernel.org> Date: Mon, 22 Apr 2024 12:31:26 +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 bpf-next v4 3/3] selftests/bpf: Support nonblock for send_recv_data Content-Language: en-GB To: Geliang Tang , Mat Martineau Cc: mptcp@lists.linux.dev References: <9cd358958245f8ec87c4f553779aa4243f967a2f.1712729342.git.tanggeliang@kylinos.cn> <12aab271-da72-49b4-ac91-2091b6889856@linux.dev> <9475c2259b3d32774bc1488dd0d6004f7ddfbf13.camel@kernel.org> <52673f90-84c6-4e3d-9967-a3d0a7335c46@kernel.org> <7732f129e5c1c2ff128878be9b865115e1319b85.camel@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: <7732f129e5c1c2ff128878be9b865115e1319b85.camel@kernel.org> Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit On 22/04/2024 12:04, Geliang Tang wrote:> On Mon, 2024-04-22 at 11:45 +0200, Matthieu Baerts wrote: (...) >> I might be wrong, but with MPTCP schedulers, it is different: with >> non-blocking IO, EAGAIN can be seen, and this case needs to be >> handled. >> Actively waiting by retrying directly in the loop in case of EAGAIN >> is >> not recommended, but probably OK for the tests (still, might be good >> to >> add a comment to recommend polling instead). So here as well, such >> modifications can stay in our tree for the moment. >> >> Also, what is not clear to me is where we set the socket as the >> non-blocking one. Is it only done for MPTCP servers/clients? > > I didn't set the socket as non-block in the end. > > EAGAIN will be got no matter non-block flag is set or not. That's strange, no? When the userspace sends data with a blocking IO socket, it should not get EAGAIN, no? > In old version like "[mptcp-next,v7,0/5] setsockopt per subflow: BPF": > > https://patchwork.kernel.org/project/mptcp/cover/cover.1712571740.git.tanggeliang@kylinos.cn/ > > "set_nonblock" is added in patch 2, and invoked in run_subflow() in > patch 3. I see, but the commit message of patch 2 doesn't explain why set_nonblock() is needed for MPTCP. I see it is used in patch 3, but is it really necessary? Maybe it was added for other reasons, that are no longer valid today? >>> I added a issue #487 to trace this issue. Please also note that we didn't have this issue for a while. When we had it, it is when KVM was not supported on the CI: $ /opt/virtme/virtme-run (...) Could not access KVM kernel module: No such file or directory qemu-system-x86_64: failed to initialize kvm: No such file or directory qemu-system-x86_64: falling back to tcg Maybe we had this issue because the VM was abnormally too slow, and we reached the 3 seconds timeout described by Martin in a previous message? If this is due to the "abnormally slow setup", maybe we don't need to do anything? In other words, can you (easily) reproduce the issue on your side? With or without KVM support? Cheers, Matt -- Sponsored by the NGI0 Core fund.