From owner-freebsd-current@FreeBSD.ORG Thu Nov 17 14:59:58 2011 Return-Path: Delivered-To: freebsd-current@freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:4f8:fff6::34]) by hub.freebsd.org (Postfix) with ESMTP id 6E8881065674 for ; Thu, 17 Nov 2011 14:59:58 +0000 (UTC) (envelope-from jhb@freebsd.org) Received: from cyrus.watson.org (cyrus.watson.org [65.122.17.42]) by mx1.freebsd.org (Postfix) with ESMTP id 46B578FC1A for ; Thu, 17 Nov 2011 14:59:58 +0000 (UTC) Received: from bigwig.baldwin.cx (66.111.2.69.static.nyinternet.net [66.111.2.69]) by cyrus.watson.org (Postfix) with ESMTPSA id EF5CD46B06; Thu, 17 Nov 2011 09:59:57 -0500 (EST) Received: from jhbbsd.localnet (unknown [209.249.190.124]) by bigwig.baldwin.cx (Postfix) with ESMTPSA id 96DB98A051; Thu, 17 Nov 2011 09:59:57 -0500 (EST) From: John Baldwin To: freebsd-current@freebsd.org Date: Thu, 17 Nov 2011 09:53:58 -0500 User-Agent: KMail/1.13.5 (FreeBSD/8.2-CBSD-20110714-p8; KDE/4.5.5; amd64; ; ) References: In-Reply-To: MIME-Version: 1.0 Content-Type: Text/Plain; charset="iso-8859-1" Content-Transfer-Encoding: 7bit Message-Id: <201111170953.58151.jhb@freebsd.org> X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.2.6 (bigwig.baldwin.cx); Thu, 17 Nov 2011 09:59:57 -0500 (EST) Cc: Matteo Landi Subject: Re: ixgbe and fast interrupts X-BeenThere: freebsd-current@freebsd.org X-Mailman-Version: 2.1.5 Precedence: list List-Id: Discussions about the use of FreeBSD-current List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Thu, 17 Nov 2011 14:59:58 -0000 On Thursday, November 17, 2011 6:38:21 am Matteo Landi wrote: > Hi everybody, > > trying to measure the interrupt latency of a 10G Intel network > adapter, I find out that the the used driver (ixgbe) can can be > configured to work with both fast and standard interrupts. From my > understanding of the BUS_SETUP_INTR(9) man page and > sys/kern/kern_intr.c file, it seems that drivers in need of > registering fast interrupts should call bus_setup_intr() specifying a > filter function instead of a handler. > > My question is: why ixgbe_allocate_legacy() says it is allocating a > fast interrupt (comments and error messages say so) but instead passes > a handler instead of a filter to pci_setup_intr()? Is there anything I > am not taking into account? It is not a fast handler and is not using the fast handler stuff. OTOH, you probably want to be using MSI-X for a 10G NIC instead of INTx anyway. -- John Baldwin