From owner-freebsd-current Mon Mar 27 13:57:56 2000 Delivered-To: freebsd-current@freebsd.org Received: from mass.cdrom.com (pyramid.cdrom.com [204.216.28.136]) by hub.freebsd.org (Postfix) with ESMTP id AD5F537BAE9 for ; Mon, 27 Mar 2000 13:57:53 -0800 (PST) (envelope-from msmith@mass.cdrom.com) Received: from mass.cdrom.com (localhost [127.0.0.1]) by mass.cdrom.com (8.9.3/8.9.3) with ESMTP id OAA00995; Mon, 27 Mar 2000 14:00:20 -0800 (PST) (envelope-from msmith@mass.cdrom.com) Message-Id: <200003272200.OAA00995@mass.cdrom.com> X-Mailer: exmh version 2.1.1 10/15/1999 To: nate@yogotech.com (Nate Williams) Cc: Matthew Dillon , Daniel Eischen , nms@otdel-1.org, freebsd-current@FreeBSD.ORG Subject: Re: Is there spinlocks/semaphores available for drivers? In-reply-to: Your message of "Mon, 27 Mar 2000 10:55:57 MST." <200003271755.KAA26648@nomad.yogotech.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Mon, 27 Mar 2000 14:00:20 -0800 From: Mike Smith Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > > :> The word 'too bad' comes to mind re: shared interrupts. > > : > > :Too bad is not acceptable. If we want to support multi-function > > :PCMCIA/CardBus cards, we *must* do shared interrupts, and multi-function > > :cards are becoming the standard, rather than the exception. > > > > First, each PCI slot has *two* assignable interrupts. Four, actually, although the typical routing setup reduces their effectiveness. > > Second, CardBus cards are so slow that you would see absolutely no > > gain in performance whatsoever by being able to run concurrent interrupt > > threads for a single shared interrupt. > > Huh? CardBus cards are *not* slow. PCMCIA cards are, but CardBus is > pretty dang fast. I think you're at cross purposes here. Matt's point is that you wouldn't be able to run interrupt handler threads for more than one device on a shared interrupt at a time, not that you would never be able to support shared interrupts. -- \\ Give a man a fish, and you feed him for a day. \\ Mike Smith \\ Tell him he should learn how to fish himself, \\ msmith@freebsd.org \\ and he'll hate you for a lifetime. \\ msmith@cdrom.com To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message