Date: Tue, 03 Sep 2019 14:07:48 -0000 From: "Andrey V. Elsukov" <bu7cher@yandex.ru> To: Slava Shwartsman <slavash@FreeBSD.org>, src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Subject: Re: svn commit: r341586 - head/sys/dev/mlx5/mlx5_en Message-ID: <a1ff0879-abae-25c5-9350-809186d2cf85@yandex.ru> In-Reply-To: <201812051425.wB5EP38T004562@repo.freebsd.org> References: <201812051425.wB5EP38T004562@repo.freebsd.org>
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This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --Gc4FCLxF5RLpVDUgQhYnJWt4CbwtXFWML Content-Type: multipart/mixed; boundary="CkT7XhrlVpnZaZvea4uGJsDAgElFOplO3"; protected-headers="v1" From: "Andrey V. Elsukov" <bu7cher@yandex.ru> To: Slava Shwartsman <slavash@FreeBSD.org>, src-committers@freebsd.org, svn-src-all@freebsd.org, svn-src-head@freebsd.org Message-ID: <a1ff0879-abae-25c5-9350-809186d2cf85@yandex.ru> Subject: Re: svn commit: r341586 - head/sys/dev/mlx5/mlx5_en References: <201812051425.wB5EP38T004562@repo.freebsd.org> In-Reply-To: <201812051425.wB5EP38T004562@repo.freebsd.org> --CkT7XhrlVpnZaZvea4uGJsDAgElFOplO3 Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 05.12.2018 17:25, Slava Shwartsman wrote: > Author: slavash > Date: Wed Dec 5 14:25:03 2018 > New Revision: 341586 > URL: https://svnweb.freebsd.org/changeset/base/341586 >=20 > Log: > mlx5en: Implement backpressure indication. > =20 > The backpressure indication is implemented using an unlimited rate ty= pe of > mbuf send tag. When the upper layers typically the socket layer has o= btained such > a tag, it can then query the destination driver queue for the current= > amount of space available in the send queue. > =20 > A single mbuf send tag may be referenced multiple times and a refcoun= t has been added > to the mlx5e_priv structure to track its usage. Because the send tag = resides > in the mlx5e_channel structure, there is no need to wait for refcount= s to reach > zero until the mlx4en(4) driver is detached. The channels structure i= s persistant > during the lifetime of the mlx5en(4) driver it belongs to and can so = be accessed > without any need of synchronization. > =20 > The mlx5e_snd_tag structure was extended to contain a type field, bec= ause there are now > two different tag types which end up in the driver which need to be d= istinguished. > =20 > Submitted by: hselasky@ > Approved by: hselasky (mentor) > MFC after: 1 week > Sponsored by: Mellanox Technologies > @@ -587,27 +609,33 @@ mlx5e_xmit(struct ifnet *ifp, struct mbuf *mb) > struct mlx5e_sq *sq; > int ret; > =20 > - sq =3D mlx5e_select_queue(ifp, mb); > - if (unlikely(sq =3D=3D NULL)) { > -#ifdef RATELIMIT > - /* Check for route change */ > - if (mb->m_pkthdr.snd_tag !=3D NULL && > - mb->m_pkthdr.snd_tag->ifp !=3D ifp) { > + if (mb->m_pkthdr.snd_tag !=3D NULL) { > + sq =3D mlx5e_select_queue_by_send_tag(ifp, mb); > + if (unlikely(sq =3D=3D NULL)) { > + /* Check for route change */ > + if (mb->m_pkthdr.snd_tag->ifp !=3D ifp) { > + /* Free mbuf */ > + m_freem(mb); > + > + /* > + * Tell upper layers about route > + * change and to re-transmit this > + * packet: > + */ > + return (EAGAIN); > + } Hi, I just discovered something strange and found that this commit is the cause. The test system has mlx5en 100G interface. It has two vlans: vlan500 and vlan100. Via vlan500 it receives some packets flows. Then it routes these packets into vlan100. But packets are dropped in mlx5e_xmit() with EAGAIN error code. # dtrace -n 'fbt::ip6_output:return {printf("%d", arg1);}' dtrace: description 'fbt::ip6_output:return ' matched 1 probe CPU ID FUNCTION:NAME 23 54338 ip6_output:return 35 16 54338 ip6_output:return 35 21 54338 ip6_output:return 35 22 54338 ip6_output:return 35 24 54338 ip6_output:return 35 23 54338 ip6_output:return 35 14 54338 ip6_output:return 35 ^C # dtrace -n 'fbt::mlx5e_xmit:return {printf("%d", arg1);}' dtrace: description 'fbt::mlx5e_xmit:return ' matched 1 probe CPU ID FUNCTION:NAME 16 69030 mlx5e_xmit:return 35 23 69030 mlx5e_xmit:return 35 26 69030 mlx5e_xmit:return 35 25 69030 mlx5e_xmit:return 35 24 69030 mlx5e_xmit:return 35 21 69030 mlx5e_xmit:return 35 26 69030 mlx5e_xmit:return 35 ^C The kernel config is GENERIC. 13.0-CURRENT #9 r345758+82f3d57(svn_head)-dirty --=20 WBR, Andrey V. Elsukov --CkT7XhrlVpnZaZvea4uGJsDAgElFOplO3-- --Gc4FCLxF5RLpVDUgQhYnJWt4CbwtXFWML Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- Comment: Using GnuPG with Thunderbird - https://www.enigmail.net/ iQEzBAEBCAAdFiEE5lkeG0HaFRbwybwAAcXqBBDIoXoFAly16TMACgkQAcXqBBDI oXoZfAf9Glf7TAruR75X9vsJ2J7jytk8xLTYCTW+U3kmjOToyIWEpmy1HNUDWN7p jjBvOijhFwZSXzV6mLL/Iy7D3xtomzl/a2Dn4sCKoM5TvYvHim2aQZtPlDnG3BI6 o4Qs705lnCl0li46Ilpmvv9wtdXCXqf9U9ayJe+3BPLojy/ryiXSrdT0EJyI0F3B d+pyntzQDw1EHlFXrn1paHiTkBjt1V+Hk7gwPP+w8jH6MnIj+Z2Awx6UpGbHfQ36 29JI087K98zG4AIadH0YPj0+myk2eVFzMSQj5Sr/LPU1HwPBtZzLVYD4zEjeRgKk GnzVIEoAWxkKU4Q3l2FgfM1csAMhWw== =yi8C -----END PGP SIGNATURE----- --Gc4FCLxF5RLpVDUgQhYnJWt4CbwtXFWML--
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