From mboxrd@z Thu Jan 1 00:00:00 1970 From: Ben Hutchings Subject: Re: [PATCH net-next 3/4] ethtool: Support for configurable RSS hash key. Date: Thu, 23 Jan 2014 15:09:16 +0000 Message-ID: <1390489756.1547.13.camel@deadeye.wl.decadent.org.uk> References: <1390156048.16433.114.camel@deadeye.wl.decadent.org.uk> <1390224028.3651.72.camel@deadeye.wl.decadent.org.uk> <1390455540.3651.136.camel@deadeye.wl.decadent.org.uk> Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha512"; protocol="application/pgp-signature"; boundary="=-Qc6B9jrG3jLjYUaut/c5" Cc: "netdev@vger.kernel.org" To: Venkata Duvvuru Return-path: Received: from shadbolt.e.decadent.org.uk ([88.96.1.126]:44443 "EHLO shadbolt.e.decadent.org.uk" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S932082AbaAWPJa (ORCPT ); Thu, 23 Jan 2014 10:09:30 -0500 In-Reply-To: Sender: netdev-owner@vger.kernel.org List-ID: --=-Qc6B9jrG3jLjYUaut/c5 Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Thu, 2014-01-23 at 13:47 +0000, Venkata Duvvuru wrote: > > -----Original Message----- > > From: Ben Hutchings [mailto:ben@decadent.org.uk] > > Sent: Thursday, January 23, 2014 11:09 AM > > To: Venkata Duvvuru > > Cc: netdev@vger.kernel.org > > Subject: Re: [PATCH net-next 3/4] ethtool: Support for configurable RSS= hash > > key. > >=20 > > On Wed, 2014-01-22 at 12:12 +0000, Venkata Duvvuru wrote: > > [...] > > > > No, what I mean is: > > > > > > > > 1. An RX flow steering filter can specify use of RSS, in which case > > > > the value looked up in the indirection is added to the queue number > > > > specified in the filter. This is not yet controllable through RX > > > > NFC though there is room for extension there. > > > > > > > > 2. Multi-function controllers need multiple RSS contexts (key + > > > > indirection > > > > table) to support independent use of RSS on each function. > > > > But it may also be possible to allocate multiple contexts to a sing= le > > function. > > > > This could be useful in conjunction with 1. But there would need t= o > > > > be a way to allocate and configure extra contexts first. > > > The proposed changes will be incremental so I think this can be done > > > in a separate patch. Thoughts? > >=20 > > The ethtool ABI (to userland) has to remain backward-compatible, and it= is > > preferable if we don't add lots of different structures for this. > >=20 > > So please define the new command structure to include both the key and > > indirection table, and some reserved space (documented as 'userland mus= t > > set to 0') for future extensions. >=20 > I think it=E2=80=99s better to keep key and indirection table settings as > different ethtool commands. We can probably add rss contexts (reserved > space) to both the command structures. > If we mix key and indirection table into one command structure then it > will hamper the compatibility. [...] Right, there is no compatible way to extend struct ethtool_rxfh_indir. I should have thought ahead when defining it! But the new structure doesn't need to have that problem. Ben. --=20 Ben Hutchings compatible: Gracefully accepts erroneous data from any source --=-Qc6B9jrG3jLjYUaut/c5 Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.15 (GNU/Linux) iQIVAwUAUuEwnOe/yOyVhhEJAQrogg//djKvaD1BljAiOz/+v9TPmAY+ZHHonLLC q6WtK7Jpb+PFusYMg3XjpgQfa2IbyFxLAcyazVNUDHjnRp8Q+FOlc98sA3xG6B55 KcZifWBBjQ08L/GpaJdR11xroH5+0+D+JaRc96HUxxmqDtrHqQGolCjFVbhE9uNI taz4e44oYIbzmKTcG4ThOHLEKfgAp/4clZbS3vg3wkDoHdb1tRvd1JLvsJm42eud mC8qRSvLSeqbKl4NDOvfSg7eQw0HVOx/9XLrNocFeSOfbcOg/VDpymNQFwaHqX9X FXYjY2dWp7nRWLQ1EuhY8sljF2w1MWjXq0nghVlqSKHYoHhbZVyS8/nTfBdlOHrZ BipBeuWdGRlgQWPMfTxyAiULpLuzWGXIyZ4whms+YfB5jVBfdFEwg57QRguZsrw1 21MqAfhI1wxJY6x1W/BRRnGRztgDHToQMHtH4Vt2Pqjsd+Pk7qP7bE2WVDhXEmms S/wUqrNOUe8sNksjBlJiLLCO9IYPezcm1468EP/J6KtQmDK6bjBYY+ydyTfnN5ZA ozOrAyF7+rbDlKRx4RHjCtruaJpGijzdS5xAHq6hNoQphZZoaVH8Mp0HvJWe8aR2 pYQepcx/HAR/SDCE/c7y5hjLgtHg1rVqcdtTI5LBcLI+s4YRucQijf+TWshiG/Ns fG7kxubDPDU= =9Aq/ -----END PGP SIGNATURE----- --=-Qc6B9jrG3jLjYUaut/c5--