Skip site navigation (1)Skip section navigation (2)
Date:      Mon, 23 Mar 2015 16:42:14 -0700
From:      hiren panchasara <hiren@strugglingcoder.info>
To:        freebsd-net@freebsd.org, jfv@freebsd.org, erj@freebsd.org
Cc:        Adrian Chadd <adrian@freebsd.org>, Jason Wolfe <nitroboost@gmail.com>
Subject:   Full 32bit flowid from igb(4)
Message-ID:  <20150323234214.GU53237@strugglingcoder.info>
In-Reply-To: <20150323233908.GT53237@strugglingcoder.info>
References:  <20150323233908.GT53237@strugglingcoder.info>

next in thread | previous in thread | raw e-mail | index | archive | help

--R7Dyui215VKdTDYA
Content-Type: text/plain; charset=us-ascii
Content-Disposition: inline
Content-Transfer-Encoding: quoted-printable

Correcting Eric's email and subject line.

On 03/23/15 at 04:39P, hiren panchasara wrote:
> scottl@freebsd.org
> Bcc:=20
> Subject: Full 32bit flowid from igb(4) [was: Re: Unbalanced LACP link]
> Reply-To:=20
> In-Reply-To: <20150319175145.GH53237@strugglingcoder.info>
>=20
> On 03/19/15 at 10:51P, hiren panchasara wrote:
> > On 03/17/15 at 12:34P, Adrian Chadd wrote:
> > > On 17 March 2015 at 11:33, Jason Wolfe <nitroboost@gmail.com> wrote:
> > > > On Mon, Mar 16, 2015 at 2:43 AM, Hans Petter Selasky <hps@selasky.o=
rg> wrote:
> > > >> On 03/16/15 10:37, Vitalii Duk wrote:
> > > >>>
> > > >>> I've changed use_flowid to 0 and it helped! But isn't it setting
> > > >>> significant? In a description it says "Shift flowid bits to preve=
nt
> > > >>> multiqueue collisions".
> > > >>
> > > >>
> > > >> Hi,
> > > >>
> > > >> Maybe your ethernet hardware is not properly setting the m_flowid =
=2E..
> > > >>
> > > >> --HPS
> > > >>
> > > >
> > > > Flip use_flowid back to 1 and try setting
> > > > net.link.lagg.default_flowid_shift / net.link.lagg.X.flowid_shift t=
o 0
> > > > as Hiren suggested.  r260179 added this shift, which has caused us
> > > > balancing issues with the i350/igb.
> > > >
> > > > https://svnweb.freebsd.org/base?view=3Drevision&revision=3D260179
> > > >
> > > > Based on Adrian's comment about igb/ixgbe not setting the 'full
> > > > flowid' under normal conditions, does that mean this shift should b=
e 0
> > > > by default to ensure we don't break balancing for devices that only
> > > > set the CPU/MSIX queue?
> > >=20
> > > Or we can just see if there's anything wrong with putting the full 32
> > > bit RSS flowid in received packets that have them.
> >=20
> > It'd be nice to have but for now I am proposing following to fix a known
> > broken case because of an optimization:
> > https://reviews.freebsd.org/D2098
>=20
> Turns out, setting flowid_shift to 0 is not the correct solution. Please
> look at the review above for more details.=20
>=20
> Looking at the code, we have a way to get full flowid but it's hidden
> under "ifdef RSS":
>     rxr->fmp->m_pkthdr.flowid =3D le32toh(cur->wb.lower.hi_dword.rss);
>=20
> Using just this line gives me good hash on I350 igb(4) chipset that we
> have.
>=20
> Is it possible to expose this outside RSS? Would this break other
> things/chips?
>=20
> Cheers,
> Hiren


--R7Dyui215VKdTDYA
Content-Type: application/pgp-signature

-----BEGIN PGP SIGNATURE-----
Version: GnuPG v2.0.22 (FreeBSD)
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=
=F6OG
-----END PGP SIGNATURE-----

--R7Dyui215VKdTDYA--



Want to link to this message? Use this URL: <https://mail-archive.FreeBSD.org/cgi/mid.cgi?20150323234214.GU53237>