Date: Fri, 18 Oct 2002 09:53:27 -0700 From: Eli Dart <dart@nersc.gov> To: "Jim McGrath" <jimmcgra@bellatlantic.net> Cc: "Petri Helenius" <pete@he.iki.fi>, "Luigi Rizzo" <rizzo@icir.org>, "Lars Eggert" <larse@ISI.EDU>, freebsd-net@FreeBSD.ORG Subject: Re: ENOBUFS Message-ID: <20021018165327.559193B1AE@gemini.nersc.gov> In-Reply-To: Message from "Jim McGrath" <jimmcgra@bellatlantic.net> of "Fri, 18 Oct 2002 09:21:37 EDT." <NDBBKKEELKBCJJBEGDECOEHJCGAA.jimmcgra@bellatlantic.net>
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--==_Exmh_128925830P Content-Type: text/plain; charset=iso-8859-1 Content-Transfer-Encoding: quoted-printable In reply to "Jim McGrath" <jimmcgra@bellatlantic.net> : > = > > Where could I get the errata sheet? > = > Product Specification Updates i.e. errata, and the Product Specificatio= n > itself are available from Intel under a Non Disclosure Agreement. Unle= ss > you work for a company that is doing business with Intel, they are prob= ably > not obtainable. > > > > Could the numbers be packet thresholds? 28 and 128 packets respective= ly? > > > I can't answer that directly because of NDA. Let us apply some logic h= ere. > If they were packet counts, under very low load conditions e.g. a singl= e > telnet session, the telnet link would be unusable. This leads us to th= e > conclusion that they must be time values. Based on the source code for the sk driver (look for "interrupt = moderation" in if_sk.c) I would suspect that those values represent = time in microseconds. My guess (based on no privileged information = whatsoever) is that if we've not interrupted in <timeout> = microseconds and we have something to send (or we've received = something) go ahead and raise an interrupt..... Just a guess. I'm perfectly willing to be wrong about this.... --eli > = > Jim > > Anything else that can be done? Does PCI width/speed affect the amoun= t of > > time spent in the kernel interrupt or are the PCI transfers asynchron= ous? > > > > Pete > > > > ----- Original Message ----- > > From: "Jim McGrath" <jimmcgra@bellatlantic.net> > > To: "Luigi Rizzo" <rizzo@icir.org>; "Petri Helenius" <pete@he.iki.fi>= > > Cc: "Lars Eggert" <larse@ISI.EDU>; <freebsd-net@FreeBSD.ORG> > > Sent: Friday, October 18, 2002 7:49 AM > > Subject: RE: ENOBUFS > > > > > > > Careful here. Read the errata sheet!! I do not believe the em > > driver uses > > > these parameters, and possibly for a good reason. > > > > > > Jim > > > > > > > -----Original Message----- > > > > From: owner-freebsd-net@FreeBSD.ORG > > > > [mailto:owner-freebsd-net@FreeBSD.ORG]On Behalf Of Luigi Rizzo > > > > Sent: Thursday, October 17, 2002 11:12 PM > > > > To: Petri Helenius > > > > Cc: Lars Eggert; freebsd-net@FreeBSD.ORG > > > > Subject: Re: ENOBUFS > > > > > > > > > > > > On Thu, Oct 17, 2002 at 11:55:24PM +0300, Petri Helenius wrote: > > > > ... > > > > > I seem to get about 5-6 packets on an interrupt. Is this tunabl= e? At > > > > > > > > just reading the source code, yes, it appears that the card has > > > > support for delayed rx/tx interrupts -- see RIDV and TIDV definit= ions > > > > and usage in sys/dev/em/* . I don't know in what units are the va= lues > > > > (28 and 128, respectively), but it does appear that tx interrupts= are > > > > delayed a bit more than rx interrupts. > > > > > > > > They are not user-configurable at the moment though, you need > > to rebuild > > > > the kernel. > > > > > > > > cheers > > > > luigi > > > > > > > > > 50kpps the card generates 10k interrupts a second. Sending gene= rates > > > > > way less. This is about 300Mbps so with the average packet size= of > > > > > 750 there should be room for more packets on the interface queu= e > > > > > before needing to service an interrupt? > > > > > > > > > > What=B4s the way to access kernel adapter-structure? Is there > > an utility > > > > > that can view the values there? > > > > > > > > > > > Pete > > > > > > > > > > > > > > > > > > To Unsubscribe: send mail to majordomo@FreeBSD.org > > > > with "unsubscribe freebsd-net" in the body of the message > > > > > > > > > > > > > > > = > = > To Unsubscribe: send mail to majordomo@FreeBSD.org > with "unsubscribe freebsd-net" in the body of the message --==_Exmh_128925830P Content-Type: application/pgp-signature -----BEGIN PGP SIGNATURE----- Version: GnuPG v1.0.6 (FreeBSD) Comment: This is a comment. iD8DBQE9sDyHLTFEeF+CsrMRAj3SAKDnmZM7GH1u8JAajyz6boZB7oeLEQCgiQJJ 5jP8QSLOwQE2OcI/xd9xbuo= =PgrR -----END PGP SIGNATURE----- --==_Exmh_128925830P-- To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message
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