From mboxrd@z Thu Jan 1 00:00:00 1970 From: Jeff Kirsher Subject: Re: [net-next 11/13] igb: Make Tx budget for NAPI user adjustable Date: Mon, 19 Sep 2011 16:36:29 -0700 Message-ID: <1316475390.2184.8.camel@jtkirshe-mobl> References: <4E776441.9090602@intel.com> <1316448352.2764.27.camel@bwh-desktop> <4E776E92.6090303@intel.com> <20110919.170033.344802441047363137.davem@davemloft.net> <4E77C1D4.503@intel.com> Reply-To: jeffrey.t.kirsher@intel.com Mime-Version: 1.0 Content-Type: multipart/signed; micalg="pgp-sha1"; protocol="application/pgp-signature"; boundary="=-MKJmJ3+9x01L2WoQgQCs" Cc: David Miller , "bhutchings@solarflare.com" , "netdev@vger.kernel.org" , "gospo@redhat.com" To: "Duyck, Alexander H" Return-path: Received: from mga09.intel.com ([134.134.136.24]:13803 "EHLO mga09.intel.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1750901Ab1ISXgo (ORCPT ); Mon, 19 Sep 2011 19:36:44 -0400 In-Reply-To: <4E77C1D4.503@intel.com> Sender: netdev-owner@vger.kernel.org List-ID: --=-MKJmJ3+9x01L2WoQgQCs Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable On Mon, 2011-09-19 at 15:27 -0700, Duyck, Alexander H wrote: > On 09/19/2011 02:00 PM, David Miller wrote: > > From: Alexander Duyck > > Date: Mon, 19 Sep 2011 09:32:18 -0700 > >> The fact is ixgbe has been using this parameter this way for over 2 > >> years now and the main goal of this patch was just to synchronize how > >> things work on igb and ixgbe. > >> > >> Our hardware doesn't have a mechanism for firing an interrupt after X > >> number of frames so instead we simply have modified things so that we > >> will only process X number of frames and then fire another > >> interrupt/poll if needed. As such we aren't that far out of > >> compliance with the meaning of how this parameter is supposed to be > >> used. > > All I can say is this was a huge mistake you therefore need to revert > > the IXGBE change, these ethtool settings are not for changing NAPI or > > software interrupt behavior. > > > > And if you guys plan to be difficult on this and refuse to remove the > > IXGBE bits, I'm letting you guys know ahead of time that I'll do it > > for you. > > > > If the hardware can't support this facility, neither should these > > ethtool hooks, because the whole point is to avoid hardware interrupts > > from firing using these parameters. > > > > Propose new mechanisms to control NAPI behavior if you want. > I'll remove the ixgbe code if that is what you want. It may be a month= =20 > or so before I can get to it though since I am slammed with work so if= =20 > you are in a hurry for it you might want to work with Jeff Kirsher to=20 > have the code removed. Alex- I will work on this to resolve the issues the Ben and Dave have pointed out. >=20 > As far as this current patch goes I honestly don't have the time to add= =20 > or rewrite yet another ethtool interface so I will probably just see=20 > about dropping the ethtool portion of this patch and update the=20 > description in order to make it acceptable. >=20 > Thanks, >=20 > Alex --=-MKJmJ3+9x01L2WoQgQCs Content-Type: application/pgp-signature; name="signature.asc" Content-Description: This is a digitally signed message part Content-Transfer-Encoding: 7bit -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.4.11 (GNU/Linux) iQEcBAABAgAGBQJOd9H9AAoJECTsCADr/EWUzXoH/iBZ84VtUYWKYrJATeci8G0l oMZCFRbnA8QieypW1ymPF1rRw3RbgZEre6rrZe+44J7pH74SLDK3mLSzae0V+v8E xXqPKOsx6gxos72djdTupo+0WGq52pO+/l8Kty50HNng7nxTawHN2Zmi+w7Hqdjd TIlr7nVdSRxD3JJMXdeBFZGwZRHGs/s5bRx8tcbsnsJLJprBEMtpjAm9MEpfCzYG TuWEIaG2uVHLWPjypQgxKuv8M8bguSB+mBTPBN2Za0zHgOcCuqV7A8uJwa4Ld+uR jPuGk+N3fke4q2HNB6qulUS6buIqgKGfD3MW/NImlCfzcZExHSwO3yoOgNGWd8o= =bAHc -----END PGP SIGNATURE----- --=-MKJmJ3+9x01L2WoQgQCs--