From owner-freebsd-net Fri Oct 18 10:27:29 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 EDB5337B401 for ; Fri, 18 Oct 2002 10:27:27 -0700 (PDT) Received: from pimout1-ext.prodigy.net (pimout1-ext.prodigy.net [207.115.63.77]) by mx1.FreeBSD.org (Postfix) with ESMTP id 422C543E9C for ; Fri, 18 Oct 2002 10:27:27 -0700 (PDT) (envelope-from kbyanc@posi.net) Received: from gateway.posi.net (adsl-63-201-92-224.dsl.snfc21.pacbell.net [63.201.92.224]) by pimout1-ext.prodigy.net (8.12.3 da nor stuldap/8.12.3) with ESMTP id g9IHR5LE362954; Fri, 18 Oct 2002 13:27:05 -0400 Received: from localhost (localhost [127.0.0.1]) by gateway.posi.net (8.12.6/8.12.5) with ESMTP id g9IHR4OQ001632; Fri, 18 Oct 2002 10:27:04 -0700 (PDT) (envelope-from kbyanc@posi.net) Date: Fri, 18 Oct 2002 10:27:04 -0700 (PDT) From: Kelly Yancey To: Petri Helenius Cc: Luigi Rizzo , Lars Eggert , Subject: Re: ENOBUFS In-Reply-To: <0d0b01c27680$b553ba90$8c2a40c1@PHE> Message-ID: <20021018102515.V1611-100000@gateway.posi.net> MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=X-UNKNOWN Content-Transfer-Encoding: QUOTED-PRINTABLE 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 On Fri, 18 Oct 2002, Petri Helenius wrote: > > > > 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. > > > The thing what is looking suspect is also the "small packet interrupt" fe= ature > which does not seem to get modified in the em driver but is on the define= s. > > If that would be on by default, we=B4d probably see interrupts "too often= " > because it tries to optimize interrupts for good throughput on small numb= er > of TCP streams. > Hmm. Might that explain the abysmal performance of the em driver with packets smaller than 333 bytes? Kelly -- Kelly Yancey -- kbyanc@{posi.net,FreeBSD.org} FreeBSD, The Power To Serve: http://www.freebsd.org/ To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-net" in the body of the message