From owner-freebsd-net Fri Oct 18 8:21:46 2002 Delivered-To: freebsd-net@freebsd.org Received: from mx1.FreeBSD.org (mx1.freebsd.org [216.136.204.125]) by hub.freebsd.org (Postfix) with ESMTP id 8143437B401 for ; Fri, 18 Oct 2002 08:21:43 -0700 (PDT) Received: from silver.he.iki.fi (silver.he.iki.fi [193.64.42.241]) by mx1.FreeBSD.org (Postfix) with ESMTP id 3127843E65 for ; Fri, 18 Oct 2002 08:21:42 -0700 (PDT) (envelope-from pete@he.iki.fi) Received: from PHE (silver.he.iki.fi [193.64.42.241]) by silver.he.iki.fi (8.12.6/8.11.4) with SMTP id g9IFL8Yj085103; Fri, 18 Oct 2002 18:21:25 +0300 (EEST) (envelope-from pete@he.iki.fi) Message-ID: <00b001c276ba$1533dbf0$3500080a@PHE> From: "Petri Helenius" To: "Jim McGrath" , "Luigi Rizzo" Cc: "Lars Eggert" , , References: Subject: Re: ENOBUFS Date: Fri, 18 Oct 2002 18:21:37 +0300 MIME-Version: 1.0 Content-Type: text/plain; charset="iso-8859-1" Content-Transfer-Encoding: 8bit X-Priority: 3 X-MSMail-Priority: Normal X-Mailer: Microsoft Outlook Express 6.00.2800.1106 X-MimeOLE: Produced By Microsoft MimeOLE V6.00.2800.1106 Sender: owner-freebsd-net@FreeBSD.ORG Precedence: bulk List-ID: List-Archive: (Web Archive) List-Help: (List Instructions) List-Subscribe: List-Unsubscribe: X-Loop: FreeBSD.org (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