Date: Mon, 30 Mar 2015 15:59:45 -0700 From: hiren panchasara <hiren@strugglingcoder.info> To: Adrian Chadd <adrian@freebsd.org> Cc: Jack F Vogel <jfv@freebsd.org>, FreeBSD Net <freebsd-net@freebsd.org>, erj@freebsd.org, Jack Vogel <jfvogel@gmail.com>, Jason Wolfe <nitroboost@gmail.com> Subject: Re: Full 32bit flowid from igb(4) Message-ID: <20150330225945.GI10892@strugglingcoder.info> In-Reply-To: <CAJ-Vmo=ajfWokQ3bdu1Ww8kV3AdVwwsDpoS9y_%2Bywk%2BgcrbBvQ@mail.gmail.com> References: <20150323233908.GT53237@strugglingcoder.info> <20150323234214.GU53237@strugglingcoder.info> <CAFOYbc=f3OT85z50uqYEnBUkEej=8FRnRP8TpQuTStgqUEoDTA@mail.gmail.com> <20150324154931.GC53237@strugglingcoder.info> <CAJ-Vmo=ajfWokQ3bdu1Ww8kV3AdVwwsDpoS9y_%2Bywk%2BgcrbBvQ@mail.gmail.com>
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--+PbGPm1eXpwOoWkI Content-Type: text/plain; charset=us-ascii Content-Disposition: inline Content-Transfer-Encoding: quoted-printable On 03/24/15 at 01:51P, Adrian Chadd wrote: > Hi, >=20 > The main reason I didn't add it outside of RSS is that I didn't want > to impact the behaviour that was there before. Before, it wasn't using > the flowid - only the msix/queue id. It'd break things if not all igb chips behave the same way in this regard. In which case, we'd have to fix them on per-case basis by pointing broken ones to the old behavior. >=20 > I read the intel datasheets about that particular field - I'm pretty > sure that by default we'll only see RSS hashed packets for IPv4/IPv6, > however non v4/v6 packets won't have a flowid. I guess that'd be okay for tiny traffic going through non-hashed. > There are also cases of > the flow director or some hardware checksum config using the same > field as the flowid. I don't understand your point here. Which field do you refer to as "the same field"? Can you please explain a bit more? >=20 > The /full/ solution would very carefully check the return status and > ensure what's in the flowid field is a flowid. Yes, I am waiting for Eric or Jack to comment on it. >=20 > The "sometimes it may have a flowid, sometimes it won't" problem isn't > so bad with kernel RSS enabled - it'll just software hash it. True. Cheers, Hiren --+PbGPm1eXpwOoWkI Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v2.0.22 (FreeBSD) iQF8BAEBCgBmBQJVGdVgXxSAAAAAAC4AKGlzc3Vlci1mcHJAbm90YXRpb25zLm9w ZW5wZ3AuZmlmdGhob3JzZW1hbi5uZXRBNEUyMEZBMUQ4Nzg4RjNGMTdFNjZGMDI4 QjkyNTBFMTU2M0VERkU1AAoJEIuSUOFWPt/l5EMH/31tknnYUFrwNRKdm5+mIrnR fg0sgMfFed113f4/qVYLp1JwaY8oRCl+uSnQUgGdYAAyr7/8D6z/qLC71VhrWLjU 9V+mzK6Eqq5Q+uIDvZVAsTULYvR83PxiyjxjACWTDT3FR0RSf0uzf3PMABGAMVk9 BXl7qN/3Dz84yQ8zOb6PuqeYMXW93z/qWL28giAvytdcfG+1eZkPSgH2HCR1frWB UUtwecCcDELYbUpTSob9N8Z5hnTw/D/GmkwKnFvC/YozX4nwmOkHT7lwTT+GpVve NBRbmrN0uBv38KkGfApWwtoZ+jKhoxRyvwAyoLT/OarEntcqxgsa1nQblADrYdI= =7y9Z -----END PGP SIGNATURE----- --+PbGPm1eXpwOoWkI--
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