From owner-freebsd-hackers Fri Feb 27 19:15:16 1998 Return-Path: Received: (from majordom@localhost) by hub.freebsd.org (8.8.8/8.8.8) id TAA01918 for freebsd-hackers-outgoing; Fri, 27 Feb 1998 19:15:16 -0800 (PST) (envelope-from owner-freebsd-hackers@FreeBSD.ORG) Received: from cynic.portal.ca (root@cynic.portal.ca [204.174.36.7]) by hub.freebsd.org (8.8.8/8.8.8) with ESMTP id TAA01870 for ; Fri, 27 Feb 1998 19:15:06 -0800 (PST) (envelope-from cjs@portal.ca) Received: from localhost ([[UNIX: localhost]]) by cynic.portal.ca (8.8.5/8.8.5) with SMTP id TAA18850; Fri, 27 Feb 1998 19:14:50 -0800 (PST) X-Authentication-Warning: cynic.portal.ca: cjs owned process doing -bs Date: Fri, 27 Feb 1998 19:14:50 -0800 (PST) From: Curt Sampson To: Mike Smith cc: Dan Janowski , hackers@FreeBSD.ORG Subject: Re: "Best" Fast Ethernet Card In-Reply-To: <199802280243.SAA00310@dingo.cdrom.com> Message-ID: MIME-Version: 1.0 Content-Type: TEXT/PLAIN; charset=US-ASCII Sender: owner-freebsd-hackers@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG On Fri, 27 Feb 1998, Mike Smith wrote: > > > The question is how to measure CPU overhead, since that is the issue at > > > hand. > > > > netperf has done this for ages. > > It can measure interrupt handler execution time for just the adapter > driver? No. But you don't need that. You just need to run netperf on the same completely idle system with each network card and see the overall difference in CPU utilisation. This has the added advantage that this will catch other problems with the driver, such as having to copy due to bad alignment or things like that. (This is probably not a big deal on i386, but the Intel chipset's ability to pad the in-memory Ethernet header by a couple of bytes is a godsend on Alphas, where you generally want the IP header to be aligned.) cjs Curt Sampson cjs@portal.ca Info at http://www.portal.ca/ Internet Portal Services, Inc. Through infinite mist, software reverberates Vancouver, BC (604) 257-9400 In code possess'd of invisible folly. To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-hackers" in the body of the message