From owner-freebsd-current Mon Mar 27 9:56:16 2000 Delivered-To: freebsd-current@freebsd.org Received: from ns.yogotech.com (ns.yogotech.com [206.127.79.126]) by hub.freebsd.org (Postfix) with ESMTP id 5BD2037B80A for ; Mon, 27 Mar 2000 09:56:12 -0800 (PST) (envelope-from nate@yogotech.com) Received: from nomad.yogotech.com (nomad.yogotech.com [206.127.79.115]) by ns.yogotech.com (8.9.3/8.9.3) with ESMTP id KAA06106; Mon, 27 Mar 2000 10:55:57 -0700 (MST) (envelope-from nate@nomad.yogotech.com) Received: (from nate@localhost) by nomad.yogotech.com (8.8.8/8.8.8) id KAA26648; Mon, 27 Mar 2000 10:55:57 -0700 (MST) (envelope-from nate) Date: Mon, 27 Mar 2000 10:55:57 -0700 (MST) Message-Id: <200003271755.KAA26648@nomad.yogotech.com> From: Nate Williams MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit To: Matthew Dillon Cc: Nate Williams , Daniel Eischen , nms@otdel-1.org, freebsd-current@FreeBSD.ORG Subject: Re: Is there spinlocks/semaphores available for drivers? In-Reply-To: <200003271753.JAA41782@apollo.backplane.com> References: <200003271731.JAA41585@apollo.backplane.com> <200003271746.KAA26582@nomad.yogotech.com> <200003271753.JAA41782@apollo.backplane.com> X-Mailer: VM 6.34 under 19.16 "Lille" XEmacs Lucid Reply-To: nate@yogotech.com (Nate Williams) Sender: owner-freebsd-current@FreeBSD.ORG Precedence: bulk X-Loop: FreeBSD.ORG > :> :> *not* preempted except when being interrupted, so there are no > :> :> 'priorities', per say. Or, rather, the relative priority is strictly > :> :> that the interrupt takes priority over supervisor code except when > :> :> disabled by said supervisor code. > :> : > :> :But locks with owners wouldn't have to disable interrupts (given that > :> :we have interrupt threads). What about shared interrupts? You could > :> :still field and process the interrupt as long as it was for a different > :> :device. > :> :Dan Eischen > :> > :> 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. > : > :Nate > > First, each PCI slot has *two* assignable interrupts. > > 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. Nate To Unsubscribe: send mail to majordomo@FreeBSD.org with "unsubscribe freebsd-current" in the body of the message