From mboxrd@z Thu Jan 1 00:00:00 1970 Received: from mail.ozlabs.org (mail.ozlabs.org [IPv6:2404:9400:2221:ea00::3]) by passt.top (Postfix) with ESMTPS id 452E45A004E for ; Wed, 24 Jul 2024 02:56:08 +0200 (CEST) DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=gibson.dropbear.id.au; s=202312; t=1721782564; bh=Ty0l1B7+6qy2B49v33OIefh6YYo50X2Rt3FUx6mVeuE=; h=Date:From:To:Cc:Subject:References:In-Reply-To:From; b=hLEaTM39+HihZZFVMvP3P/KCYrJoBgESQGDAfMuzHbO046qUKpUS3bS2S1I8k6F10 iCuPZNbY9BnCeXKoTmi9GsEcYMgK7tdQGEAXeFwr6DkNb83u1upXvJScy7oM+gFgnF uP1516na3EJoijSky0y8rdCFC7Nch6CxMQvq5ZrdF6lFTSvej3G2Xx0R/2gPXp/QhA aY7Hb0VSS8PmCvyl9wwSxTZUFEdCDuKZkU9+0iXDJA1PR+t2vS1YzRZsiMatB4L355 hIq4BBCYTL700y846iU6LYe5dNPY1C2eGsfHz1XaiqRzGQzUQhZr7tnSU7TaZWWac2 two7JpWtuGsug== Received: by gandalf.ozlabs.org (Postfix, from userid 1007) id 4WTFv84JNXz4wc4; Wed, 24 Jul 2024 10:56:04 +1000 (AEST) Date: Wed, 24 Jul 2024 10:40:15 +1000 From: David Gibson To: Stefano Brivio Subject: Re: [PATCH v2] tcp: probe for SO_PEEK_OFF both in tcpv4 and tcp6 Message-ID: References: <20240722220937.3663437-1-sbrivio@redhat.com> <20240723222936.1c301d30@elisabeth> MIME-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="xEOrrR9qr7A1zZkG" Content-Disposition: inline In-Reply-To: <20240723222936.1c301d30@elisabeth> Message-ID-Hash: H6JA5G5REBR6YUFYLTYUUAP5R7QJBGSG X-Message-ID-Hash: H6JA5G5REBR6YUFYLTYUUAP5R7QJBGSG X-MailFrom: dgibson@gandalf.ozlabs.org X-Mailman-Rule-Misses: dmarc-mitigation; no-senders; approved; emergency; loop; banned-address; member-moderation; nonmember-moderation; administrivia; implicit-dest; max-recipients; max-size; news-moderation; no-subject; digests; suspicious-header CC: passt-dev@passt.top, Jon Maloy X-Mailman-Version: 3.3.8 Precedence: list List-Id: Development discussion and patches for passt Archived-At: Archived-At: List-Archive: List-Archive: List-Help: List-Owner: List-Post: List-Subscribe: List-Unsubscribe: --xEOrrR9qr7A1zZkG Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On Tue, Jul 23, 2024 at 10:29:36PM +0200, Stefano Brivio wrote: > On Tue, 23 Jul 2024 00:09:37 +0200 > Stefano Brivio wrote: >=20 > > From: Jon Maloy > >=20 > > Based on an original patch by Jon Maloy: > >=20 >=20 > ...so, with this, the probing issue is solved: on a 6.10 kernel, > SO_PEEK_OFF is not used, unless I disable IPv6 (with --ipv4-only / -4). >=20 > However, if I disable it, for some reason, resorting to IPv4, at least > together with the flow table (applying just this patch to HEAD), I get > something that looks like one of the "old" TCP stalls. On the host: >=20 > $ ./passt -f -t 10000 -4 >=20 > and in the guest: >=20 > # ip link set dev eth0 up > # dhclient eth0 > # iperf3 -s -p 10000 >=20 > back to the host: >=20 > $ iperf3 -c 127.0.0.1 -p 10000 > Connecting to host 127.0.0.1, port 10000 > [ 5] local 127.0.0.1 port 39046 connected to 127.0.0.1 port 10000 > [ ID] Interval Transfer Bitrate Retr Cwnd > [ 5] 0.00-1.00 sec 11.2 MBytes 94.3 Mbits/sec 0 5.50 MBytes= =20 > [ 5] 1.00-2.00 sec 0.00 Bytes 0.00 bits/sec 0 5.50 MBytes = =20 > [ 5] 2.00-3.00 sec 0.00 Bytes 0.00 bits/sec 0 5.50 MBytes = =20 >=20 > ...the transfer never recovers. Bother. I've reproduced and am debugging now. > I didn't really have time to debug this further. >=20 > At the moment I would be inclined to temporarily revert commit > e63d281871ef ("tcp: leverage support of SO_PEEK_OFF socket option when > available"), but it's not a good idea if this happens to be hiding some > (unlikely?) issue with the flow table. >=20 --=20 David Gibson (he or they) | I'll have my music baroque, and my code david AT gibson.dropbear.id.au | minimalist, thank you, not the other way | around. http://www.ozlabs.org/~dgibson --xEOrrR9qr7A1zZkG Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEO+dNsU4E3yXUXRK2zQJF27ox2GcFAmagTWoACgkQzQJF27ox 2GfJYw/+PWYs2iUeM5QEQHnsKRpor0l+onVAOrbcAMsf98H/gBO/Os6LJBuI+RjO O5/aZrmp0Natw6hI0q6EQ05LcVpkC7yfaXFKlqxje+Lfie/PKYrlvBNYC5pR6MoQ VkNaGuL716dDoqqhZA0Tg5qy3WD4WCKhR5/b+ufAhWzU4R58JXlSfZ+GoQ7035i9 gA8H2B9+wP1QqEAoMUMNLO5p86liJ9wykMCwQlL6/6fG+8C2wOVM5mlf4D+o9Jl3 /0nj84qvIhOuBEI+RRvT3qz6nYGu0xkWKpknGtZd9vUZf6tEf41T6ItgCAi8CaCY wBt0q0VCfGOnMDdcOGLKzTfcpIiMNYUc3jlXIWniBiGL7NLJ/IP8HQhID5c80brw 0sNVDc6CMf5IAQyvbpWvihqtsstg3/YuhFUugvepx/iUZE8I+NM+MFMcJKM4QIXu HP3YWkc4jQuOkHZI78ChDRw7RFKACYyJgwKz/ghZbAXUgUwGuOp2JCqgOFDZIfJ/ g1eLfbjAZJMVYR1EDkRwG1Rk3B4aB+VlI0cMKdBegHI8k3+kcAZIQMwPmEy7SA2y DdiYdqFLufUdjygb1x/FXZ5eta0l4g/HXpdVEdUbU9eGYQh6dhmeXB3LbpjK7cJs LTVPn7nte6sRzorJ3coERerbeuWHbqqcOwLGXSI3+ykti3GueI4= =vrKz -----END PGP SIGNATURE----- --xEOrrR9qr7A1zZkG--