Date: Fri, 18 Oct 2002 18:21:37 +0300 From: "Petri Helenius" <pete@he.iki.fi> To: "Jim McGrath" <jimmcgra@bellatlantic.net>, "Luigi Rizzo" <rizzo@icir.org> Cc: "Lars Eggert" <larse@ISI.EDU>, <freebsd-net@FreeBSD.ORG>, <freebsdnic@mailbox.cps.intel.com> Subject: Re: ENOBUFS Message-ID: <00b001c276ba$1533dbf0$3500080a@PHE> References: <NDBBKKEELKBCJJBEGDECCEHJCGAA.jimmcgra@bellatlantic.net>
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(IŽll throw in the address found in the README of the driver, maybe somebody there has access to appropriate documentation / is willing to work on documenting tunables and optimizing the performance) > I have to tread carefully here because I was under NDA at my previous > company. My work was with the wx driver, but hardware problems are hardware > problems. There are a lot of performance enhancing features in the 82544. The chips I have are 82546. Is your recommendation to steer away from Intel Gigabit Ethernet chips? What would be more optimal alternative? > You will notice that the em driver does not use them. This may be for a > reason :-( Our implementation ran with transmit interrupts disabled, so I > can't comment on TIDV and am not allowed to comment on RIDV. > Maybe IŽll play with the value and see what happens. Any comments on the question how to access the adapter structure from userland? > The Receive Descriptor Threshold interrupt showed promise under high load > (Rx interrupts disabled) but you would need to add a timeout function, 1 > msec. or faster, to process receive descriptors under low load. > LuigiŽs polling work would be useful here. That would lead to incorrect timestamps on the packets, though? Pete > > > -----Original Message----- > > From: owner-freebsd-net@FreeBSD.ORG > > [mailto:owner-freebsd-net@FreeBSD.ORG]On Behalf Of Luigi Rizzo > > Sent: Friday, October 18, 2002 12:56 AM > > To: Jim McGrath > > Cc: Petri Helenius; Lars Eggert; freebsd-net@FreeBSD.ORG > > Subject: Re: ENOBUFS > > > > > > On Fri, Oct 18, 2002 at 12:49:04AM -0400, Jim McGrath wrote: > > > Careful here. Read the errata sheet!! I do not believe the em > > driver uses > > > these parameters, and possibly for a good reason. > > > > as if i had access to the data sheets :) > > > > cheers > > luigi > > > 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 tunable? At > > > > > > > > just reading the source code, yes, it appears that the card has > > > > support for delayed rx/tx interrupts -- see RIDV and TIDV definitions > > > > and usage in sys/dev/em/* . I don't know in what units are the values > > > > (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. > > > > 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
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