Return-Path: Received: (majordomo@vger.kernel.org) by vger.kernel.org via listexpand id S1751114AbXBRD7d (ORCPT ); Sat, 17 Feb 2007 22:59:33 -0500 Received: (majordomo@vger.kernel.org) by vger.kernel.org id S1751126AbXBRD7c (ORCPT ); Sat, 17 Feb 2007 22:59:32 -0500 Received: from ebiederm.dsl.xmission.com ([166.70.28.69]:46937 "EHLO ebiederm.dsl.xmission.com" rhost-flags-OK-OK-OK-OK) by vger.kernel.org with ESMTP id S1751019AbXBRD7b (ORCPT ); Sat, 17 Feb 2007 22:59:31 -0500 From: ebiederm@xmission.com (Eric W. Biederman) To: Benjamin Herrenschmidt Cc: Russell King , linux-arch@vger.kernel.org, linux-kernel@vger.kernel.org, Linus Torvalds , Andrew Morton , Andi Kleen , Ingo Molnar , Alan Cox , Arnd Bergmann Subject: Re: [RFC] killing the NR_IRQS arrays. References: <200702162045.58857.arnd@arndb.de> <20070216195256.GE2572@flint.arm.linux.org.uk> <1171747222.5644.143.camel@localhost.localdomain> Date: Sat, 17 Feb 2007 20:58:26 -0700 In-Reply-To: <1171747222.5644.143.camel@localhost.localdomain> (Benjamin Herrenschmidt's message of "Sun, 18 Feb 2007 08:20:22 +1100") Message-ID: User-Agent: Gnus/5.110006 (No Gnus v0.6) Emacs/21.4 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Sender: linux-kernel-owner@vger.kernel.org X-Mailing-List: linux-kernel@vger.kernel.org Content-Length: 1064 Lines: 28 Benjamin Herrenschmidt writes: > >> We might need this. But I don't think we need reference counting in >> the traditional sense. For all practical purpose we already have >> dynamic irq allocation and it hasn't proven necessary. I would >> prefer to go to lengths to avoid having to expose that kind of >> an issue to driver code. > > I think we do need proper refcounting, but I also think that most > drivers will not need to see it. > > For example, a PCI driver will most probably just do something along the > lines of the existing request_irq(pdev->irq), the liftime of pdev->irq > is managed by the PCI core. > > Same goes with MSIs imho, the MSI core can manage the lifetime > transparently. Yes. I'm optimistic that we won't find a case where refcounting will be needed. Eric - To unsubscribe from this list: send the line "unsubscribe linux-kernel" in the body of a message to majordomo@vger.kernel.org More majordomo info at http://vger.kernel.org/majordomo-info.html Please read the FAQ at http://www.tux.org/lkml/